LisaList2

General Category => LisaList2 => Topic started by: AlexTheCat123 on May 27, 2021, 07:23:35 pm

Title: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: AlexTheCat123 on May 27, 2021, 07:23:35 pm
You guys helped me fix my heavily corroded Lisa a while back, but unfortunately it's having problems again. I started having problems where it wouldn't turn on and when it occasionally would power up, it would give error beeps indicating that the I/O board was bad and the CRT wouldn't display anything. I got tired of the corroded and flaky I/O board, so I ordered a bare I/O PCB from John at VintageMicros around a week ago and got it fully assembled. I also made an X/COPS to replace the COP421. Now the computer will turn on when I press the power switch and the CRT turns on, which is an improvement, but clearly things still aren't working right (see the attached picture). There is also no sound of any kind from the speaker (no clicks or beeps). I'm assuming that this problem has something to do with the CPU board since it handles video generation, but I can't really probe it with the oscilloscope to figure anything out since it's inaccessible while the card cage is installed. Does anyone have any tips or suggestions of what to try next? Thanks for the help!
Title: Re: Lisa Video Issue
Post by: rayarachelian on May 27, 2021, 08:49:09 pm
It could be something to do with the VSROM which is used by the video state machine to generate the horizontal and vertical sync signals.
Could also be an issue with the RAM.

But both of these would indeed point to the CPU board, if there's not even a beep it could be the CPU never starts (although a bad COPS VIA6522 would stop it from beeping even if the CPU is running.)

See if you can hook up your scope to ground + one of the CPU pins, maybe A1 or D0 and see if anything is moving there. That would at least tell you if anything's running.
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on May 28, 2021, 02:19:47 pm
I just probed the address and data lines of the CPU and there's definitely activity. What should I try next?
Title: Re: Lisa Video Issue
Post by: rayarachelian on May 28, 2021, 03:34:24 pm
I just probed the address and data lines of the CPU and there's definitely activity. What should I try next?

That's a good sign. I'm guessing the RAM boards are ok as they worked before, right? You could also try with just one CPU board or the other if you happen to have two.
Without RAM, there's nothing that can be displayed.

I'd look at the CPU board schematics and locate the VSROM and the things it talks to - that's the video state machine. Something around there's not working - though it could be something related to the analog board. I do see some diagonal lines on the display, those are a sign that some horizontal retrace is happening.

I take it you've played around with the trimpots on the video board using a plastic screwdriver already.

Some other things to try, pin #19 (CB2) on VIA #1 (with the other end to GND) produces sound via a timer + shift register output so I'd attach the scope to that and power it on, it might be trying to beep some codes but if the speaker isn't working you won't hear them. The scope should be able to pick up the tones graphically and you could figure out what they're trying to say: https://lisafaq.sunder.net/single.html#lisafaq-hw-rom_beeps - you might have trouble telling high vs low tones apart graphically if they're all high or all low, so you might need to guess around those codes. Might help if the scope has some audible mode to help you with that, or if you have something you could attach to that pin that leads to an amplifier - but be careful not to fry your VIA.  An old pen style logic probe that beeps might do the trick to get sound out also.

If you see nothing, either the CPU can't talk to the VIA or something else is broken along the path from the CPU board to the I/O board.

If you have a spare VSROM to swap out that would help eliminate that. If not you might try this one: https://www.ebay.com/itm/142796459701 - but it could also be something else around there.

Inserting a blank or PC formatted floppy might be useful too though it might also eat it and not let go until you fix the problem - the idea here is that it will see the floppy as unreadable and should eject it. That would tell you that the 68000 and the Boot ROM are working.

Another thought which you might be able to verify if you don't detect any beeps: Since you're not seeing video, and you're not hearing beeps or clicks or anything like that, it might also be the motherboard. Perhaps some contacts aren't touching or are dirty and so the CPU board video state machine can't read the RAM and turn it into a video signal and it can't talk to the I/O board so it can't beep.

Checking for broken solder joints on the motherboard where the CPU connector is might help, as would cleaning the contacts, reflowing the solder, etc.

Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on May 28, 2021, 05:16:07 pm
Good news! It lookes like one of the address lines going to the CPU was broken, so I patched the trace and now it actually displays something meaningful on the screen! It's great to have the Lisa at least sort of working again after months of attempts to fix it. Both the CPU and memory boards pass the self test, but the I/O board takes around 20 seconds to test (I remember it testing almost instantly back before I started having problems with the computer) and it gives an error code of 57. I also hear a beep code, so the speaker seems to be working as well. I looked up error 57 and it seems to be related to the floppy disk controller, but the schematic for the disk controller section of the I/O board looks pretty complicated and I'm not really sure where to start for troubleshooting this section of the board. Also, the ROM revision for the CPU board correctly shows up in the upper right hand corner of the screen as revision H, but the I/O ROM shows up as revision 00, which definitely isn't right. Please note that I am using the Sun Remarketing 800K ROM instead of the original Apple one.
Title: Re: Lisa Video Issue
Post by: rayarachelian on May 28, 2021, 06:52:24 pm
Good news! It lookes like one of the address lines going to the CPU was broken, so I patched the trace and now it actually displays something meaningful on the screen! It's great to have the Lisa at least sort of working again after months of attempts to fix it. Both the CPU and memory boards pass the self test, but the I/O board takes around 20 seconds to test (I remember it testing almost instantly back before I started having problems with the computer) and it gives an error code of 57. I also hear a beep code, so the speaker seems to be working as well. I looked up error 57 and it seems to be related to the floppy disk controller, but the schematic for the disk controller section of the I/O board looks pretty complicated and I'm not really sure where to start for troubleshooting this section of the board. Also, the ROM revision for the CPU board correctly shows up in the upper right hand corner of the screen as revision H, but the I/O ROM shows up as revision 00, which definitely isn't right. Please note that I am using the Sun Remarketing 800K ROM instead of the original Apple one.

So for sure, showing version 00 is not right, it means the 6504 failed to report the version. The 6504 runs from the I/O ROM. They share about 1KB of RAM - so when the Boot ROM tried to talk to the I/O ROM it failed to get what it wanted, so next you should check that the CPU can access the shared floppy RAM. Error 57 actually means "57 = bus error accessing disk controller" - which explains both the slow access as well as the 00.

Here's the code for it:
Code: [Select]
1136|                       ;  Check disk alive indicator
1136|
1136| 4282                          CLR.L   D2              ;clear for use                          CHG022
1138| 227C 00FC D901                MOVE.L  #VIA2BASE,A1    ;set ptr to parallel port 6522
113E| 0229 00BF 0010                ANDI.B  #$BF,DDRB2(A1)  ;ensure bit 6 is input
1144| 203C 001C 8000                MOVE.L  #DSKTMOUT,D0    ;set up timeout count for 15 secs
114A| 0811 0006             @2      BTST    #DSKDIAG,IRB2(A1) ;check indicator
114E| 6606                          BNE.S   @3              ;skip if set
1150| 5380                          SUBQ.L  #1,D0           ;else loop until timeout (about 8 us per loop)
1152| 66F6                          BNE.S   @2
1154| 7439                          MOVEQ   #EDISK,D2       ;error if not set                       CHG022

There's also some code that decides what type of machine it is by reading the I/O ROM version from 00FCC031 - if you go in service mode you can try to read from this address and see what's there.  It should be A8 for a 2/5, or 88 for a 2/10 - even with the 800k drive.

My guess is you might have yet another address line somewhere, this time one that leads to the floppy controller that is broken. However, that timeout loop above that sets code EDISK also happens if FDIR isn't responding. So that might be an issue with VIA #2.
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on May 28, 2021, 07:39:30 pm
I tried swapping the two VIAs around and the problem didn't go away, so I think that the VIAs are fine. I checked all of the data lines coming from the floppy RAM (BD0-BD7) and they all look fine, but the 8th address line that connects to the floppy RAM, the ROM, and the 6504 is showing some weird behavior. All of the other lines are around 5 volts peak to peak, but this address line is only around 1 volt peak to peak. It looks like this behavior is coming from the line MA8 (I'm not really sure about its purpose) that feeds into the multiplexer at U4C that in turn connects to the RAM, ROM, and 6504 address lines. I'm assuming that this is likely the source of the problem, right? If I hit the reset switch, the address line looks normal for around half a second, but then it goes right back to this weird one volt peak to peak behavior again.
Title: Re: Lisa Video Issue
Post by: rayarachelian on May 28, 2021, 08:33:05 pm
I tried swapping the two VIAs around and the problem didn't go away, so I think that the VIAs are fine. I checked all of the data lines coming from the floppy RAM (BD0-BD7) and they all look fine, but the 8th address line that connects to the floppy RAM, the ROM, and the 6504 is showing some weird behavior. All of the other lines are around 5 volts peak to peak, but this address line is only around 1 volt peak to peak.

Maybe something's pulling it down to (near) ground. MA8 is just the 8th address line going to the 6504. I see it's on the I/O ROM EEPROM, no?
Yeah U4C is yet another mux, likely used in address decoding/chip selection.

A thought occurs, likely this mux is used in allowing access from the 68000, if so, maybe something on the CPU board leading to it is the cause of the issue? Maybe A9 since both MA8 and A9 are inputs to adder 2 on that mux?

Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on May 28, 2021, 10:14:11 pm
Since the only things connected to MA8 are the 6504 and the ROM, I would guess that one of them is causing the weird problem. I think I might just try replacing the 6504 and the ROM to see if that does anything unless you can think of any other reasons for MA8 to be acting strangely.
Title: Re: Lisa Video Issue
Post by: rayarachelian on May 29, 2021, 10:32:36 am
Since the only things connected to MA8 are the 6504 and the ROM, I would guess that one of them is causing the weird problem. I think I might just try replacing the 6504 and the ROM to see if that does anything unless you can think of any other reasons for MA8 to be acting strangely.

Yeah, but the 68k does get shared access to that bus, that's why there's the FDIR and DISKDIAG lines - to gate access, but for whatever reason MA8 + A9 go through U4C LS157 ( https://www.ti.com/lit/ds/sdls058a/sdls058a.pdf?ts=1622261683812 ) as 2A and 2B and output as 2Y which goes to RA8 and the U1B + U2B 444C-3 SRAMs, perhaps there's something there with A9 to check.

I'm assuming 444C-3's are SRAM because the pinouts of these two seem a lot like what you'd see in an 4 bit SRAM, and their power goes to the battery backed up +5B which matches the HWG, however I wasn't able to find a datasheet for these by searching the web.

A9 has an address of 512, however the 68000 accesses only the odd bytes of the shared memory, it's going to hit address 256+(A1-A8) which is in the range of the shared 1K SRAM, not just the 6504's ROM.

So what I'm trying to say is that if, and that's a big if, A9 is stuck on, and the I/O lines bypass the usual shared address semantics, it would interfere with the 6504's access to the bus, and we've already seen a similar issue with your Lisa, so maybe this is more of the same? So if the 6504 is blocked by lines from the 68000 stuck on, then it wouldn't be able to go through it's power on test and it wouldn't be able to write it's ROM version in the shared SRAM address or do much else, and then when the Lisa Boot ROM reads it, it would see 00 for the version number.

I mean, unless I'm misreading the schematic? https://lisaem.sunder.net/cgi-bin/bookview2.cgi?zoom=0?page=8?book=6?Go=Go
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on May 29, 2021, 12:56:28 pm
I see what you're saying now. I just checked A1-A10 at the inputs to the muxes and five of them (A5, A7, A8, A9, and A10) are stuck either high or low, which doesn't seem normal, so you were probably right about the problem being on the CPU board after all. Now it's just a matter of figuring out what exactly the problem is.

Edit: It actually looks like those five address lines have activity up until the Lisa starts testing the I/O board. They only get stuck after the I/O board test begins.
Title: Re: Lisa Video Issue
Post by: rayarachelian on May 29, 2021, 01:24:22 pm
Edit: It actually looks like those five address lines have activity up until the Lisa starts testing the I/O board. They only get stuck after the I/O board test begins.

:( that is truly bizarre, is there something on the I/O board doing that? I don't see how anything other than the CPU should be able to set the address lines, and why would they lock?

Do you have a spare CPU (not board) to swap out with?

I can understand the CPU hitting addresses 00fcxxxx as it touches I/O space, but it should also go back and forth with the ROM which is at 00fexxxx and lower RAM - at least where the video display page is, which should be the highest 32K of the physical RAM, so those lines should be bouncing around, not fixed.
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on May 29, 2021, 01:56:03 pm
I have two spare known-good CPUs and they both do the exact same thing as this one. I also have a spare CPU board, but something's wrong with it and there isn't any activity on the CPU's address or data buses. This is a really weird problem! Maybe the CPU's getting stuck in some sort of a loop as a result of not being able to read the contents of the shared floppy RAM?
Title: Re: Lisa Video Issue
Post by: rayarachelian on May 29, 2021, 03:34:30 pm
There is a STOP opcode, but it's unlikely to be invoked. Generally it's used to sit in an idle state until an interrupt happens.

Even if things so south, generally in the Lisa Boot ROM, you should still be able to use the mouse and keyboard, and so the CPU should still function and the address lines shouldn't be locked down, even then, it should switch between reading from the boot ROM, accessing RAM, COPS, VIA, etc.

Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on May 29, 2021, 05:24:55 pm
Both the mouse and keyboard are inoperative for me. I don't know if it's a COPS error (unlikely, since it has been replaced with a brand new and freshly assembled X/COPS) or if it's something related to the strange address line behavior. I hope that the replacement 6504 and I/O board ROM that I ordered will free up that stuck MA8 line and maybe get everything working again, but I'm not too confident about that. The 6504 does get pretty hot, so maybe something is wrong with it.
Title: Re: Lisa Video Issue
Post by: rayarachelian on May 30, 2021, 08:19:08 pm
Quote
The 6504 does get pretty hot, so maybe something is wrong with it.

That doesn't sound good at all. :( Hope your replacements arrive soon.
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on May 30, 2021, 09:00:12 pm
Quote
Hope your replacements arrive soon.

I hope so too! The only place that I could find a replacement 6504 was in China, so it could take around two weeks to get here. The 2732 ROM will arrive on Wednesday or Thursday, though. I'll keep you posted about the results of installing the new parts!
Title: Re: Lisa Video Issue
Post by: rayarachelian on May 30, 2021, 10:26:04 pm
Yeah, it could have gone bad, but, any chance there's a short somewhere on the 6504's socket, or an output being sent to something that only the 6504 itself should output like address lines?

If you pull out the 6504 and put it on a breadboard and give it +5V and GND, does it also heat up? I'd worry about these before replacing the 6504 with another - if something on the I/O board is causing it to fry, it will damage the replacement too.

Sadly, yeah, 6504s are rare. They're just 6502s with extra I/O lines, but ofc you can't easily replace them with a 6502.
Title: Re: Lisa Video Issue
Post by: patrick on May 31, 2021, 05:12:52 am
6502 and 6504 are based on the same die, they just have different packages. So you could use a 6502 with an adapter socket. Connect A12..15 low and /SO high. Certainly you don't want piggiback boards in a vintage machine, but for a quick check this should be acceptable.

Have you checked the reset signal on the CPU board? Sometimes capacitor C8 gets leaky and the NE556 will stick low. To confirm this, you could disconnect C8 and use the manual reset button on the back of the machine.


For the COP421 I have designed a replacement board a few years ago: http://john.ccac.rwth-aachen.de:8000/patrick/COPSreader.htm (http://john.ccac.rwth-aachen.de:8000/patrick/COPSreader.htm). This was intended as a tool for software analysis, but could also be used as a replacement for a defective part.
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on May 31, 2021, 10:35:54 am
Quote
Yeah, it could have gone bad, but, any chance there's a short somewhere on the 6504's socket, or an output being sent to something that only the 6504 itself should output like address lines?

I've checked the socket and there aren't any shorts or any signals going places that they shouldn't.

Quote
If you pull out the 6504 and put it on a breadboard and give it +5V and GND, does it also heat up?

Yep. It still heats up on the breadboard.

Quote
Have you checked the reset signal on the CPU board?

The reset signal looks good. It goes low for around a second to reset the 6504 and then it goes high again.

Quote
For the COP421 I have designed a replacement board a few years ago

I made one of your COP421 replacement boards a few days ago and I have it installed in my Lisa right now. I think I accidentally called it the X/COPS in a few previous posts because I was browsing eBay and saw one that seems to be made by VintageMicros that's called X/COPS and I just got the names mixed up. It doesn't seem to be relaying signals from the keyboard and mouse to the VIA, but it's definitely sending signals to the LS153 mux that connects to the keyboard and mouse and it's sending sync pulses to the keyboard as it should. I'm guessing that this is related to the I/O board error 57 that I'm getting and that it will start sending these signals to the VIA once the Lisa can pass the self-test without any errors.
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on May 31, 2021, 05:16:22 pm
Finally I've got some good-ish news! The disk controller problem is still a thing, but I did get the keyboard and mouse working! I decided to desolder the COP421 from my original I/O board and move it to the new board and that fixed the keyboard and mouse problems. I guess something's wrong with my COP421 replacement board, but I'm not sure what it could be since I have verified that the contents of the EPROM are correct and I've checked that all of the connections on the adapter board are good. With the keyboard and mouse working, I'm now able to enter service mode and I checked the memory location that you specified for where version of the I/O ROM is located. It matches the 00 that is displayed in the upper right hand corner of the screen during the self-test. With this problem fixed, I guess it's just a matter of getting the floppy controller working and figuring out what's wrong with my COP421 replacement board. The COP421 issue is particularly weird because my COP replacement seems to handle soft power-on just fine, making it seem like it's executing code properly, but the keyboard, mouse, and soft power-off don't work.
Title: Re: Lisa Video Issue
Post by: Lisa2 on May 31, 2021, 05:23:37 pm
Let it be known that the 6507 CPU is a direct replacement for the 6504 CPU on the Lisa I/O board.   The 6507 may be a little easier to find since it was used in millions of Atari video games. There is a minor difference on one or two of the pins but they are not used on the Lisa.  As already was mentioned the Die is a 6502 on both the 6504 and the 6507, just with different pins brought out in the package.
HTH,
Rick
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on May 31, 2021, 05:47:52 pm
Quote
Let it be known that the 6507 CPU is a direct replacement for the 6504 CPU on the Lisa I/O board.

That's good to know! I wish I'd realized that before I bought a 6504 from China...
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 01, 2021, 08:22:42 pm
I just got the replacement 2732 I/O board EPROMs in the mail today, but my TL866II Plus programmer won't program the chips because they require a 21V Vpp when programming, but my programmer can only go up to 18V. The weird thing is that I've programmed 2716s that also require a 21V Vpp on this programmer in the past and it has worked fine, but now I'm stuck since I can't write to these EPROMs. Hopefully I can find a solution quickly and get the code into this chip!
Title: Re: Lisa Video Issue
Post by: jamesdenton on June 01, 2021, 11:43:37 pm
Can you read the ROM and compare the checksum? Wonder if that would be enough to confirm.
Title: Re: Lisa Video Issue
Post by: blusnowkitty on June 02, 2021, 01:34:47 am
I just got the replacement 2732 I/O board EPROMs in the mail today, but my TL866II Plus programmer won't program the chips because they require a 21V Vpp when programming, but my programmer can only go up to 18V. The weird thing is that I've programmed 2716s that also require a 21V Vpp on this programmer in the past and it has worked fine, but now I'm stuck since I can't write to these EPROMs. Hopefully I can find a solution quickly and get the code into this chip!

I'll throw in my two cents here; since I do so much with all kinds of old computers I went and bought myself a Willem programmer. Fairly cheap, supports the really common 27-series EPROMs. Software can be annoying to set up, though, and you need a PC with a built-in parallel port. Probably doesn't hurt to wire up a 5 volt adapter as well, otherwise you'll be trying to step up 5v at 500ma from the USB port (power only) to at most 28 volts...
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 02, 2021, 09:44:28 am
I found a strategy that, while incredibly inelegant, seems to be getting the EPROM to program. I just made a simple shell script that programs the EPROM over and over again and, after letting it run for a couple hours and then reading the contents of the chip, it seems to have successfully programmed around half the EPROM. Hopefully it will be completely programmed within a few more hours. I'm not sure how good these repeated writes are for the chip, but I bought 10 of them, so I'll still have 9 more if this somehow damages it.
Title: Re: Lisa Video Issue
Post by: patrick on June 02, 2021, 11:13:12 am
So you program 15 minutes at 18 V instead of 50 milliseconds at 21 V? Could work.

You will run into problems if you ever try to erase this chip again. But since your Lisa is supposed to last forever, this will never be necessary  ;D
Title: Re: Lisa Video Issue
Post by: rayarachelian on June 02, 2021, 12:30:04 pm
But since your Lisa is supposed to last forever, this will never be necessary  ;D

Heh, the only immortal Lisa is LisaEm ;) - and some day the only way to run it is running it inside an emulator. Yes, that may happen one day.
Title: Re: Lisa Video Issue
Post by: D.Finni on June 02, 2021, 07:55:24 pm
But since your Lisa is supposed to last forever, this will never be necessary  ;D

Heh, the only immortal Lisa is LisaEm ;) - and some day the only way to run it is running it inside an emulator. Yes, that may happen one day.
Sure, but first you'll have to finish writing the emulator and fix all of its bugs.  :P :P

*ducks and runs*
Title: Re: Lisa Video Issue
Post by: rayarachelian on June 02, 2021, 09:41:11 pm

Sure, but first you'll have to finish writing the emulator and fix all of its bugs.  :P :P

*ducks and runs*

It is open source, you can submit patches via pull reuqests. :)
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 03, 2021, 08:43:19 am
The EPROM finally finished programming after around 12 hours or so, but the problem with MA8 is exactly the same with the new chip. I guess it's just a matter of waiting for the 6504 to arrive from China now. The good news is that I just got a broken 5MB ProFile in the mail that I can try to fix in the meantime. The power supply is dead, so I'll try to test the rest of the electronics with an ATX power supply just to see if it works at all.
Title: Re: Lisa Video Issue
Post by: rayarachelian on June 03, 2021, 09:47:51 am
The EPROM finally finished programming after around 12 hours or so, but the problem with MA8 is exactly the same with the new chip. I guess it's just a matter of waiting for the 6504 to arrive from China now. The good news is that I just got a broken 5MB ProFile in the mail that I can try to fix in the meantime. The power supply is dead, so I'll try to test the rest of the electronics with an ATX power supply just to see if it works at all.

Actually that might be a good hack - if you could take photos of the ATX power supply and connection to the ProFile board, etc. could make a good HOWTO/Wiki article "Replace ProFile Power Supply with ATX PS", etc.
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 03, 2021, 12:26:45 pm
Quote
Actually that might be a good hack - if you could take photos of the ATX power supply and connection to the ProFile board, etc. could make a good HOWTO/Wiki article "Replace ProFile Power Supply with ATX PS", etc.

That's a good idea! I can take some pictures once I get everything fully connected and working. I gave the controller board the 5V and 12V that it needs from one of my ATX PSUs and tried powering it up without the hard drive connected (the drive has some problems). There's processor activity and after around 20 seconds the Ready light blinks three times, then pauses, and blinks another two times. I'm assuming this is some sort of error code related to the disk not being connected, but I couldn't find any documentation anywhere to support this.

The hard drive itself seems to have trouble spinning up. I tried spinning the motor on the bottom of the drive manually to free it up and now it at least tries to spin, but it goes really slow and the TIP120 transistors that drive the motor get very hot. Thinking that maybe the grease in the motor is just dried up, I used a hair dryer to heat up the motor and after a few minutes of the hair dryer it spun up just fine, although it was a good bit slower to get up to speed than the ProFiles that I've seen on YouTube. I was goint to let it run upside down overnight to redistribute the grease inside the motor, but then I discovered that as the motor cooled off again and the effects of the hair dryer wore off, the drive would slow down and eventually stop. One of the driver transistors popped when this happened, but I fortunately have some replacement TIP120s. Now I'm scared to try again without somehow lubricating the motor in fear that another transistor will blow. Does anyone know how to solve a problem like this? Is there a way that I can lubricate the motor?
Title: Re: Lisa Video Issue
Post by: rayarachelian on June 03, 2021, 08:00:33 pm
The hard drive itself seems to have trouble spinning up. I tried spinning the motor on the bottom of the drive manually to free it up and now it at least tries to spin, but it goes really slow and the TIP120 transistors that drive the motor get very hot. Thinking that maybe the grease in the motor is just dried up, I used a hair dryer to heat up the motor and after a few minutes of the hair dryer it spun up just fine, although it was a good bit slower to get up to speed than the ProFiles that I've seen on YouTube. I was goint to let it run upside down overnight to redistribute the grease inside the motor, but then I discovered that as the motor cooled off again and the effects of the hair dryer wore off, the drive would slow down and eventually stop. One of the driver transistors popped when this happened, but I fortunately have some replacement TIP120s. Now I'm scared to try again without somehow lubricating the motor in fear that another transistor will blow. Does anyone know how to solve a problem like this? Is there a way that I can lubricate the motor?

Sadly I've not had to do this with ProFiles, just a couple of Widgets which did start spinning up properly after that. I don't know if you'd need to open it up to lubricate it or not, or you might have to open up just the motor, not sure.

* http://www.minuszerodegrees.net/manuals/Seagate/Seagate%20ST506%20-%20Service%20Manual%20-%20May82.pdf might help?
* https://stardot.org.uk/forums/viewtopic.php?t=6954
* https://www.vcfed.org/forum/forum/genres/pcs-and-clones/29157-st-225-longevity?p=361534#post361534

The ST225 one mentions using a single drop of 3-in-1 oil, maybe that would work for the ST506?
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 04, 2021, 09:00:38 am
I just fixed the problem and now it spins up without the transistors overheating, but the method that I used was hilariously stupid. I figured that it just needed to be spun for a while to loosen things up, so I rigged up a contraption using my dad's drill press, a hole saw, and a roll of electrical tape (don't worry, the electrical tape, not the hole saw, was the thing that actually touched the motor) that would spin the drive for me. I let it run for a few hours and the spindle motor felt a lot easier to spin afterwards. I tried powering it up and it spun up much quicker than with the hair dryer and now the transistors are running much cooler. It's really loud, so I'm going to let it run upside down for a few hours to redistribute the grease and quiet it down and then I'll reconnect the analog and controller boards and see what happens. After all of this work getting the spindle motor to spin, I sure hope that the drive is good!
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 04, 2021, 10:42:34 am
I connected the drive to the controller board and fed everything the correct voltages from the ATX power supply, but the ready LED still does the three flashes, pause, and two more flashes thing that it did with no drive connected after it waits around 20 seconds for the drive to spin up. I'm assuming this is an error code of some sort, but I can't find any documentation on it, so what does this mean exactly?
Title: Re: Lisa Video Issue
Post by: rayarachelian on June 04, 2021, 01:25:58 pm
Congrats on the motor spinner you've rigged up.

Wondering if maybe you missed a cable or if something's loose? You saw that 3 blink error before when you powered on without the drive present...
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 04, 2021, 01:46:44 pm
Quote
Wondering if maybe you missed a cable or if something's loose? You saw that 3 blink error before when you powered on without the drive present...

I've checked and reseated the cables and they all look fine, but I'm still getting those blinks. The stepper motor for the heads isn't moving at all, so maybe there's something wrong with the circuitry that drives it?
Title: Re: Lisa Video Issue
Post by: patrick on June 05, 2021, 05:18:23 am
I connected the drive to the controller board and fed everything the correct voltages from the ATX power supply, but the ready LED still does the three flashes, pause, and two more flashes thing that it did with no drive connected after it waits around 20 seconds for the drive to spin up. I'm assuming this is an error code of some sort, but I can't find any documentation on it, so what does this mean exactly?

The Ready LED just indicates the state of the /PBsy pin. The controller does not provide any fault codes.

After Reset the controller waits 18 seconds for the spindle motor to spin up and tries to read the spare table. If this works, all 0x2600 block are read one after another.


You can disconnect the controller cable and leave only the motor connected. Then move the step motor manually while the spindle is running.  This should not require much force and should not generate unusual noises. Move it back to its parking position is at the outside, far away from the track zero sensor, before stopping the spindle.

Never move the heads when the drive is not spinning at nominal speed!

Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 05, 2021, 11:09:56 am
Quote
The Ready LED just indicates the state of the /PBsy pin. The controller does not provide any fault codes.

After looking at the ProFile schematic and the disassembly of the Z8 code yesterday, I started to realize that. I guess it's just trying and failing to read the spare table and the three flashes just happen to be the behavior of the /PBsy line in this situation.

Quote
You can disconnect the controller cable and leave only the motor connected. Then move the step motor manually while the spindle is running.  This should not require much force and should not generate unusual noises. Move it back to its parking position is at the outside, far away from the track zero sensor, before stopping the spindle.

I tried this and it seems to move fine without any resistance or weird noises.

I decided to probe the two ULN2074B chips that drive the stepper on the controller board and discovered that, while all four inputs to the the chips have activity on them when the ready light is flashing, only one of the four outputs going to the stepper has any activity on it. After swapping the two chips around, the single good output moved with the chip, so I'm guessing that one of the ULN2074s is completely dead and the other has only that one working output. I ordered new chips from Mouser that should be here on Monday or Tuesday, so hopefully that will fix the stepper problem.
Title: Re: Lisa Video Issue
Post by: rayarachelian on June 05, 2021, 11:30:22 am
I decided to probe the two ULN2074B chips that drive the stepper on the controller board and discovered that, while all four inputs to the the chips have activity on them when the ready light is flashing, only one of the four outputs going to the stepper has any activity on it. After swapping the two chips around, the single good output moved with the chip, so I'm guessing that one of the ULN2074s is completely dead and the other has only that one working output. I ordered new chips from Mouser that should be here on Monday or Tuesday, so hopefully that will fix the stepper problem.

Oh sorry. But I'm very glad you can still find a replacement, and glad you've found it.
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 06, 2021, 07:53:56 am
While waiting for those chips to come in the mail, I directed my attention to the ProFile's power supply. The fuse was blown and I'm assuming this happened because the hard drive drew too much current since it couldn't spin at all when the eBay seller turned it on to test it and they said that it powered on for a few seconds before the PSU died. I replaced it with a new one, connected the PSU to a load (a dead Macintosh SCSI hard drive since I didn't want to accidentally fry the ProFile if it didn't work), and it powered up just fine! All the voltage rails looked great, but around a minute later, one of the dreaded RIFA safety caps blew up, blew the fuse, and now the whole house smells terrible. I should have replaced those caps before even turning it on, but at least it's an easy fix. Using the original power supply will be much easier and cleaner than the horrendous setup I have right now with the ATX PSU.
Title: Re: Lisa Video Issue
Post by: rayarachelian on June 06, 2021, 10:40:34 am
All the voltage rails looked great, but around a minute later, one of the dreaded RIFA safety caps blew up, blew the fuse, and now the whole house smells terrible. I should have replaced those caps before even turning it on, but at least it's an easy fix. Using the original power supply will be much easier and cleaner than the horrendous setup I have right now with the ATX PSU.

Ouch! Sorry.

I guess I should recap my ProFiles also. They've never been recapped, so those "RIFA The Destroyer" caps are likely due to pop. Thanks for the reminder.
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 07, 2021, 05:17:06 pm
Great news! I got the new ULN2074s for the ProFile in the mail today and after I installed them, the head stepper came to life and started performing the surface scan! The scan seemed to finish successfully and the ready light stayed on solid like it should. I plugged it into the Lisa and the ProFile came up under the "Startup From" menu, but it gave an error 84 when I tried to boot from it. This seems to mean that the boot blocks are damaged, so I'm assuming that I can just reformat it once I get the floppy drive working and then reinstall LOS and have everything working fine, right?
Title: Re: Lisa Video Issue
Post by: rayarachelian on June 07, 2021, 05:58:49 pm
I'd poke at it with BLU or NeoWidex and check the status of the drive as this will give you more detailed info, but yeah, reinstalling the OS seems like a good next step.

And most importantly, congrats!
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 07, 2021, 06:24:29 pm
Quote
And most importantly, congrats!

Thanks! It feels great to get this lucky with an "untested" ProFile from eBay! Now it's just a matter of replacing the RIFA caps in the PSU and the ProFile will be fully repaired.

Quote
I'd poke at it with BLU or NeoWidex and check the status of the drive as this will give you more detailed info, but yeah, reinstalling the OS seems like a good next step.

Good idea. I'll give that a shot once I get the floppy controller fixed and can boot from a floppy disk. The tracking info says that the 6504 just departed from China this morning even though I ordered it a while ago, but hopefully it will be here soon!

Do you think it would be worth trying to recover any data off the ProFile before formatting it? This would be tough since I'm almost certain that my serial ports don't work due to corrosion on the motherboard so I couldn't image it with BLU, but it would suck to accidentally erase some sort of rare or prototype piece of software.
Title: Re: Lisa Video Issue
Post by: rayarachelian on June 07, 2021, 08:38:45 pm
Do you think it would be worth trying to recover any data off the ProFile before formatting it? This would be tough since I'm almost certain that my serial ports don't work due to corrosion on the motherboard so I couldn't image it with BLU, but it would suck to accidentally erase some sort of rare or prototype piece of software.

If your serial port is working, there is a way to type in a mini loader into service mode and transfer BLU over the serial port. You could use that to both probe the status of the ProFile *and* image it to see if there's anything there.

see: http://sigmasevensystems.com/blumanual.html "Lisa Simple Loader"
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 07, 2021, 09:02:02 pm
Quote
If your serial port is working, there is a way to type in a mini loader into service mode and transfer BLU over the serial port. You could use that to both probe the status of the ProFile *and* image it to see if there's anything there.

Based off the amount of corrosion on the resistor packs on the motherboard that connect to the serial ports, I highly doubt that they're working. I can buy a serial cable to try it out, though. I would just need a DB9 to DB25 null modem cable, right?
Title: Re: Lisa Video Issue
Post by: rayarachelian on June 07, 2021, 09:14:01 pm
ard that connect to the serial ports, I highly doubt that they're working. I can buy a serial cable to try it out, though. I would just need a DB9 to DB25 null modem cable, right?

Yes, that (null modem cable) and a new Lisa ;)
Title: Re: Lisa Video Issue
Post by: AlexTheCat123 on June 08, 2021, 08:44:41 am
Quote
Yes, that (null modem cable) and a new Lisa ;)

I've had so many issues with this darn Lisa that I've often considered just getting a new one, but I feel like I'm finally on the home stretch with just the serial ports, composite video output (both of these are because of the corroded motherboard), and floppy controller to fix at this point. But of course, it would never hurt to have a second Lisa  ;)

I just looked through one of my boxes of cables and I happened to find an appropriate null modem cable as well as a USB to serial adapter, so I can test the ports once I clean the corroded gunk out of them. If the serial ports don't end up working (they almost certainly won't), do you know of any good sources for a new motherboard? The resistor packs are so corroded that I doubt I'd be able to remove them from the board and the pads would most certainly be fully corroded away. I would rather have a new motherboard than run 30-something bodge wires to patch the traces and connect a new resistor pack. I know that John at VintageMicros has made some brand new unpopulated boards, but I don't really want to pay $250 for a bare PCB and I'd rather have an original for increased authenticity.
Title: Re: Lisa Video Issue
Post by: Lisa2 on June 08, 2021, 12:10:09 pm
Sorry, folks.  While trying to split the topic,  I accidentally moved Ray's last reply/post here:

https://lisalist2.com/index.php/topic,191.0.html (https://lisalist2.com/index.php/topic,191.0.html)

This was his post:

"These days, it's either VintageMicros or eBay. I think we hit the top of the curve about two years ago for parts availability sadly, and now we're at the bottom of the barrel.
You can either keep struggling and repair the boards you have, and I know it's very hard, hence my flippant "and a new Lisa" - and indeed, I feel your pain, or save up for a new mobo, or wait until one becomes available.

The odds of a working 2/5 Mobo showing up on eBay is pretty low, most that will show up will be corroded.

There's another factor here, in that most of the 2/5 machines have had a battery leak at some point in the past, and while at some point they worked despite the leak, or were patched up, the alkaline contents got into the traces of the I/O boards and slowly over time ate those infected traces. So boards that once worked over time will, or have already failed.

Most of these types of Lisas that have been sold on ebay were chopped up into parts, and the parts sold, but if you see photos of them, most are very corroded.

2/10's don't have this issue at all, but 2/10 motherboards are incompatible with 2/5 chassis due to the wiring harness and require the 2/10 I/O board.
The only exception is that it's possible to use a 2/10 I/O board in a 2/5 if you use a modified Lite adapter.

If you try the reverse, a 2/5 motherboard in a 2/10 chassis, the internal widget cables would be shorted out when a Widget is connected, but you will be able to use the external parallel port - one of my two original Lisas was this kind of FrankenLisa which caused lots of other issues.

(I'm using 2/5 and 2/10 here to simplify - 2/5 ofc refers to a Lisa 2 that has a 5MB ProFile and 2/10 refers to a 2/10 Lisa that has an internal Widget, but I'm ignoring the storage medium here to be a bit more clear instead of just saying Lisa 2. AFAIK all the Lisa 2's were "upgraded" from Lisa 1s.)

2/10s are really nice if you replace the Widget with an Aphid/XProFile/IDEFile, etc. as Widgets are pretty flaky. There are also timing issues due to clock changes on the 2/10 board, and this causes incompatibilities with 3rd party devices such as some revisions of the FloppyEmu (and the in progress Aphid). The other advantage is that Xenix assumes that if you have a 2/10, the drive must be 10MB in size, which is a problem if you happened to snake a cable out the back to an external ProFile, etc.

But yeah, as in the other thread about the total number of Lisas, most of the existing working ones are at this point owned by collectors, the damaged ones have been either trashed long in the past (sadly) and there's very little stock now. So modern replacements are encouraged when affordable.

I wonder... I don't know if it's easier to repair an existing board than to design one from scratch based on the existing board and have some place print new boards and find replacement parts and then desolder the old board and solder the components to a new board (or use new components). Both are going to be a huge uphill struggle. So given that, I think what Vintage Micros offers is actually a great price. Sure, 10-20 years ago when we thought there were 100K Lisas out, and most were working, there, those prices wouldn't make sense, now they do.

Would it be less work to build/print a replacement PCB vs buying from Vintage Micros? How much is your time and energy worth? This guy seems to have done exactly this and even added SCSI to a Lisa 2 with a D-ROM (replacing the Serial B connector for some reason): https://www.youtube.com/watch?v=Z5DraRVMVFM - but won't released his gerbers, etc.

For some of us, this situation is a lot like owning a house for a very long time  in a city whose real estate has all of a sudden hyperinflated - like San Francisco and now the owners of said house are priced out by taxes and are forced to move - that is kind of analogous to not being able to find replacement parts to keep it working."

----------
Sorry,
Rick
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: AlexTheCat123 on June 08, 2021, 01:33:47 pm
Quote
Would it be less work to build/print a replacement PCB vs buying from Vintage Micros? How much is your time and energy worth? This guy seems to have done exactly this and even added SCSI to a Lisa 2 with a D-ROM (replacing the Serial B connector for some reason): https://www.youtube.com/watch?v=Z5DraRVMVFM - but won't released his gerbers, etc.

Once you put it that way, I guess the one from VintageMicros does sound like it's priced reasonably. I was actually the person who asked that guy in the video for his Gerbers and it sucks that he won't release them.

I hooked up my serial cable and tried loading BLU over it and the Lisa actually seemed to receive the data somehow, despite how awful the motherboard looks in that area! After the entire file was sent, the loader returned control to service mode like it should, but I discovered that while the data at address 9c0 matched what the BLU manual says, the data at the entry point of c14 was very different from what the manual says it should be. I tried sending the file multiple times and I even lowered the baud rate to 9600, but the data at this point is still wrong. What could be going on here?
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: rayarachelian on June 08, 2021, 03:40:19 pm
I'd make sure you're using the latest BLU - beyond that, you could ask @Sigma7 who wrote it.
It's possible the data is not actually making it across properly, or that your cable lacks the proper lines for HW flow control (CTS/DTR/etc.) but you'd need other things working to test that (floppy/profile).
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: AlexTheCat123 on June 09, 2021, 04:04:31 pm
It turns out that the problem was a combination of me being an idiot and the Lisa not liking my USB to serial adapter. Although I checked continuity on the RX and TX lines going from serial port B to the I/O board, I didn't think to check the flow control lines until just now and it turns out that they're faulty. I soldered some wires straight from my serial cable to the appropriate pins on chips on the I/O board and it received more of the data correctly than it did before, but there were still errors. I then tried it with an old Windows 98 laptop that actually has a built-in serial port and BLU fired right up!

I powered on the ProFile and tried to read its contents to the Windows 98 computer over serial and it seemed to work fine. After looking at the disk image in a hex editor, it seems like it was running SOS for the Apple III, which explains why it wouldn't boot on the Lisa. It appears that it was previously owned by a country club in Florida based off some of the other text that I found in the disk image. I then asked BLU to exercise the disk and that seemed to work fine too. To test booting off the ProFile, I selected the option that installs BLU onto your hard disk and now it boots straight into BLU off the ProFile perfectly!

This is some encouraging news, so I guess it's just a matter of recapping the ProFile and Lisa PSUs, getting the actual serial ports working instead of running bodge wires, and fixing that darned floppy controller at this point.
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: AlexTheCat123 on June 11, 2021, 10:20:51 am
Is there a utility that will convert a DC42 image of a ProFile to a BLU image that I could transfer over to my ProFile? Since the floppy drive still isn't working, I was thinking about trying to install LOS in LisaEm, converting the resulting ProFile image to BLU format, and then sending it over to my Lisa, but I can't find a utility that will convert from DC42 format to BLU format.
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: rayarachelian on June 11, 2021, 10:42:15 am
Is there a utility that will convert a DC42 image of a ProFile to a BLU image that I could transfer over to my ProFile? Since the floppy drive still isn't working, I was thinking about trying to install LOS in LisaEm, converting the resulting ProFile image to BLU format, and then sending it over to my Lisa, but I can't find a utility that will convert from DC42 format to BLU format.

This might work: https://github.com/rayarachelian/lisaem/blob/unstable/src/tools/src/raw-to-dc42.c if not let me know and I'll add an explicit dc42-to-blu command - not sure if BLU checks for the BLU signature or not. BLU is the same format as raw, but with the ffffff block first and in there it has a BLU version #

Easiest way to build this is to build the unstable branch of LisaEm.
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: AlexTheCat123 on June 15, 2021, 11:06:21 am
The 6504 finally came in the mail and after putting it in, the floppy controller seems to be working slightly more than it was before, but it's definitely still broken. I don't get the error 57 anymore and the I/O ROM version is no longer FF, but the version is only reported as A8 every five or six times that I look at its memory address in service mode. Other times, it's seemingly random values. Sometimes, the Lisa lists two floppy drives in the Startup From... menu and other times it just lists one, so clearly something isn't right. It sometimes just hangs and sometimes gives error 39 (drive ROM can't keep up) when I try to boot from the floppy drive and BLU always gives floppy errors whenever I start it up. What should I try next?
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: rayarachelian on June 15, 2021, 12:01:49 pm
The 6504 finally came in the mail and after putting it in, the floppy controller seems to be working slightly more than it was before, but it's definitely still broken. I don't get the error 57 anymore and the I/O ROM version is no longer FF, but the version is only reported as A8 every five or six times that I look at its memory address in service mode. Other times, it's seemingly random values. Sometimes, the Lisa lists two floppy drives in the Startup From... menu and other times it just lists one, so clearly something isn't right. It sometimes just hangs and sometimes gives error 39 (drive ROM can't keep up) when I try to boot from the floppy drive and BLU always gives floppy errors whenever I start it up. What should I try next?

So either there's something wrong between the I/O board bus pins and the CPU board (i.e. motherboard connector) or the SRAM on the floppy controller is broken.

On initialization, the 6504 will write it's version to the shared SRAM. It will do this only once.

So if that value fluctuates, something is wrong either at the bus level (and we've seen this before with your Lisa) or at the SRAM level.
You can swap out the SRAM to be able to tell which.

One thing you could look at is to see the values that show up that are not A8 and map those in binary. This will tell you which bits are either broken in the SRAM or on the bus.

Another thing you could do is piggy back a second identical SRAM chip on top of the existing one. If the problem goes away that might indicate the SRAM.
However, if the existing SRAM is bad and reports "1" values where it should be "0", the 2nd SRAM will not help.

There's a tiny bit of danger to this since you're connecting two outputs together, but it's very small. Worst case you'll cause the new SRAM to burn out as well, but I don't think these are so expensive that it matters that much.

If the randomness issue doesn't go away, it's still either the SRAM or the bus.

If you have a large logic analyzer it may help you debug futher. i.e. the old Agilent/HP ones that you could interface directly to a chip. @Sigma7 introduced me to these early on in the days of LisaEm, but it turned out I didn't need to break out this big gun to work on LisaEm, and indeed I needed very little actual testing on a real Lisa in 99.999% of cases. So I'm not very well versed in how to use such test equipment. However, in this case, if you own one and have it handy it could immediately help you diagnose the issue.

All this said, the amount of time it will take you to diagnose, it might just be quicker to desolder to SRAM, solder in a socket, and then insert a new SRAM. If the problem goes away, you're done in ~30 mins. If it doesn't, you know exactly where to look next. (Well maybe some lines from the area on the I/O board where the SRAM and the logic gates that enable it to be visible to the 68000 - DISKDIAG?, to the fingers on the I/O board, to the motherboard connector, to the traces on the motherboard, to the CPU board connector, to the CPU board itself.


Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: AlexTheCat123 on June 15, 2021, 01:27:09 pm
I just wrote a simple Arduino program that will test these RAM chips by writing every possible value to each address and then reading the value back and both chips passed just fine. I guess this means that it's a bus issue, which will not be very fun to troubleshoot :(.

Quote
If you have a large logic analyzer it may help you debug futher
I have a USB logic analyzer, but the vast amount of data that it produces when connected to the Lisa makes it impossible to go through it all. The text and CSV files that it outputs are so large that I can't open them in any program without it crashing.
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: rayarachelian on June 15, 2021, 04:03:23 pm
Quote
If you have a large logic analyzer it may help you debug futher
I have a USB logic analyzer, but the vast amount of data that it produces when connected to the Lisa makes it impossible to go through it all. The text and CSV files that it outputs are so large that I can't open them in any program without it crashing.

Yeah, those HP ones understand 650x and 68000 busses and can show you what the CPU is doing, what address it accesses, read/write and value and timing.
With a USB one, you'd need specialized software to analyze it.
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: AlexTheCat123 on June 17, 2021, 10:00:40 am
So I played around with the logic analyser some more and it revealed something interesting. I hooked it up to the BD0-BD7 lines as well as the address lines A1-A7 that feed into the muxes that allow the CPU to access the shared floppy RAM. I also connected it to the select signal (S) on the muxes so that I can see when they're allowing the CPU to address the floppy RAM. I then went into service mode and tried to read the I/O ROM version number from location FCC031. Interestingly, every time it successfully read the version number, the select signal went low and stayed low for around 600ns, but each time it failed the select signal only stayed low for around 100ns. You can see this behavior in the two screenshots that I've attached. What could be causing this?
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: rayarachelian on June 17, 2021, 02:48:37 pm
So I played around with the logic analyser some more and it revealed something interesting. I hooked it up to the BD0-BD7 lines as well as the address lines A1-A7 that feed into the muxes that allow the CPU to access the shared floppy RAM. I also connected it to the select signal (S) on the muxes so that I can see when they're allowing the CPU to address the floppy RAM. I then went into service mode and tried to read the I/O ROM version number from location FCC031. Interestingly, every time it successfully read the version number, the select signal went low and stayed low for around 600ns, but each time it failed the select signal only stayed low for around 100ns. You can see this behavior in the two screenshots that I've attached. What could be causing this?

Looking at: https://lisaem.sunder.net/LisaSchem/Lisa1SysIO4.gif (https://lisaem.sunder.net/LisaSchem/Lisa1SysIO4.gif)
(https://lisaem.sunder.net/LisaSchem/Lisa1SysIO4.gif)
By Select you mean !CS on pin 8 of the two SRAMs, yes?

Could be R28 (s/b 47Ohm) or U4C LS157 pin 12 (4Y), or it's input lines 4A, 4B.  4A should go to ground, so that's easy to check.

4B goes to Y0 of U5A S139, so one of it's inputs could be the cause.

That could be the XNOR S02 gate at U8A (pin 10), A11, A12 of the 6504, but likely these aren't it as those come from the 6504 itself.

There's also some fun components in the center left of the schematic, right under the SRAMs, there's a transistor Q7 with 3 resistors going to capacitor 28.
Not sure if those can pull down the signal or mess with it, doesn't look like it, but who knows, if they're messed up in some way they might.
(R54 is acting as a pullup from the looks of it, and R26 too)
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: Lisa2 on June 17, 2021, 05:27:14 pm
Guys,
Just to clarify, the drawing that Ray linked is actually the 2/10 I/O board with the IWM chip.

I have attached the correct drawing for the 2/5 I/O board.

Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: rayarachelian on June 17, 2021, 06:08:51 pm
Just to clarify, the drawing that Ray linked is actually the 2/10 I/O board with the IWM chip.
I have attached the correct drawing for the 2/5 I/O board.

D'Oh! Thanks for that. That came from here: https://lisaem.sunder.net/cgi-bin/bookview2.cgi?zoom=0?page=8?book=6?Go=Go and is labeled "Lisa 1 I/O Board 4" - are the ones labeled "Lisa210Sys" swapped with the "Lisa1" ones?
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: AlexTheCat123 on June 17, 2021, 06:52:37 pm
Quote
By Select you mean !CS on pin 8 of the two SRAMs, yes?

No. I'm talking about the S signal that feeds into the three LS157 muxes that select between the shared RAM being addressed by the 68000 and the RAM being addressed by the 6504.

The /DTACK signal that comes out of the 8T97 on the schematic also seems to suffer from the same problem where it goes low for a much shorter period of time when the Lisa fails to properly access the shared RAM compared to when it succeeds.
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: Lisa2 on June 17, 2021, 08:35:28 pm
D'Oh! Thanks for that. That came from here: https://lisaem.sunder.net/cgi-bin/bookview2.cgi?zoom=0?page=8?book=6?Go=Go and is labeled "Lisa 1 I/O Board 4" - are the ones labeled "Lisa210Sys" swapped with the "Lisa1" ones?
I/O sheet four for both the 2/5 and 2/10 appear to be the same on the sunder site....
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: AlexTheCat123 on June 19, 2021, 06:53:37 am
I think I fixed it! It looks like the 8T97 that buffers the /DTACK signal was flaky and after replacing it the Lisa boots from floppy just fine!. Unfortunately, the ProFile started dying at around the same time. It takes forever to complete the self-test and the LOS installer will fail to initialize it. Would a low-level format be likely to fix this?
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: rayarachelian on June 19, 2021, 08:09:54 am
I think I fixed it! It looks like the 8T97 that buffers the /DTACK signal was flaky and after replacing it the Lisa boots from floppy just fine!. Unfortunately, the ProFile started dying at around the same time. It takes forever to complete the self-test and the LOS installer will fail to initialize it. Would a low-level format be likely to fix this?

Yeay! Glad you found it.

Maybe. Does NeoWidex tell you how many spared blocks there are? if there are just a few it may help, if there are a lot, it might not help at all (indicating physical damage).
But, if it's not working, and it's not an electrical issue, not much left to lose, right?

Before you do that though, is that VIA ok? Remind me again, before the power issues, was the ProFile working before, or is that an unknown?

So far you've replaced the 8T97, and the 6504, right? that indicates issues on the I/O board, what could have damaged these guys? Any chance the parallel port VIA has gone bad too? Or something from it to the port?

If at least NeoWidex is able to read blocks off the profile, especially the spare table, it should say the name is "PROFILE" at minimum and tell you it's 5MB, etc. and how many spared blocks there are, then there likely isn't a communication issue, but rather a media issue.
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: AlexTheCat123 on June 20, 2021, 11:03:57 am
Quote
Maybe. Does NeoWidex tell you how many spared blocks there are?

It says that all 20 (I'm assuming that this in in hex) spares are in use and that there are 1D bad blocks on the disk. Would a low-level format potentially help or is this drive too far gone?

Quote
Before you do that though, is that VIA ok?

I know that everything on the I/O board is just fine because my Cameo/Aphid works perfectly with it.
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: rayarachelian on June 20, 2021, 02:43:41 pm
Quote
Maybe. Does NeoWidex tell you how many spared blocks there are?

It says that all 20 (I'm assuming that this in in hex) spares are in use and that there are 1D bad blocks on the disk. Would a low-level format potentially help or is this drive too far gone?

...

I know that everything on the I/O board is just fine because my Cameo/Aphid works perfectly with it.


Ok, perfect so the port is known good - that helps a lot. Sadly if the drive has that many bad blocks, you won't be able to install LOS - I think that's the max or near the max.
Since you have the Aphid, you could have installed BLU on the Aphid before you managed to fix the 6504 and 8T97 - then powered off the Aphid and attached the ProFile, but doesn't matter now. :)

So, yes, your only recourse is the low level format procedure. You'll need to burn the piggyback LLF EEPROM for the Z8 and then you can use  BLU to Low Level Format it.

But be ready in case it won't fix the issue as that's a whole lot of spared blocks and could indicate a lot of physical damage. Let's hope they're only bad because the power supply was a bit weak and it caused the overwrote the formatting markers, etc. In that, case the LLF will absolutely fix the drive. Keeping my fingers crossed for you.

Another thing you might do if the formatting fails is to attempt to replace the ST506 with whatever the 10MB drive is and I think it might need a new EEPROM for the Z8 for that, but that's a bigger project.

Once you're ready to do the LLF, make sure you have really good power, high recommend you plug both Lisa + ProFile in a big UPS just incase. Most likely nothing will go wrong, but you'll want to make sure power is nice and clean and no brownout caused by an HVAC or whatever ruins your day.
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: AlexTheCat123 on June 20, 2021, 05:18:15 pm
I'll go ahead and try a low-level format, but there's one problem: I don't have one of the special ROMless Z8s and I can't seem to find any on eBay. @Stepleton, I saw in a previous thread that you had several of these chips that you were spreading around the Lisa community. Do you still have any of these left and if so, how much do they cost?
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: stepleton on June 20, 2021, 07:20:39 pm
Hello, the chips are free as long as they circulate around the community from person to person. So far I've only sent out one of them, and I have several more that I'd be very happy to distribute via post. The only hang-ups these days are that (a) shipping is from the UK so it could take a while unless you live nearby (b) thanks to the new, improved Delta COVID variant and the UK's vaccination scheduling, I'll be aiming to stay out of post offices for about another month or so. There is the option of at-home pickup so that might not matter so much. Feel free to shoot me a PM with your address, and we can at least get the ball rolling.
Title: Re: Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
Post by: AlexTheCat123 on August 08, 2021, 08:25:45 pm
Update: The ROMless Z8 that @Stepleton kindly sent me just arrived in the mail and a low-level format cleared up all of the ProFile issues that I was having! The drive now works perfectly and doesn't seem to have any defects at all!
Title: Re: Lisa Video Issue
Post by: compu_85 on February 09, 2023, 01:40:57 am
Have you checked the reset signal on the CPU board? Sometimes capacitor C8 gets leaky and the NE556 will stick low.

As always, Patrick's hints point in the right direction. My 2/10 had started being "lazy" when turning on, having to run for a minute or so before it would reset. Changing C8 on the cpu board solved the problem.

-J