LisaList2

Quote from: stepleton on January 24, 2026, 11:56:24 AMI've decided to give this another look. I can confirm that I need to turn 75R termination ON for the Lisa 1 and OFF for the 2/10.

Thank you for confirming this!   

Due to the composite video's analog signal path and 40+ year old Lisa hardware combined with variations in RGBtoHDMI builds, this solution is never going to be plug-and-play.  Some tweaking of the settings is bound to be required for each user. 

Rick

Quote from: stepleton on January 23, 2026, 06:21:27 PMAh yes, that's really good to know :-)
Someday stick the solder side into a flatbed scanner (or just snap a photo) so that we can have a squiz...

Will do!

Quote from: Lisa2 on January 23, 2026, 07:23:52 PMHuxley,
If you want a replacement Dual Par Card, PM me and I will hook you up.
I put together some blue boards to demo the adapter I designed for the ESProfile at VCF midwest last fall and I still have a few around.  The adapter allows you to connect two ESProfiles to the Dual Par Card at the same time.
Rick

Oh wow, that's amazing! I'll PM you now 

Quotesigma7 recommends substituting 3,4 for 2,3 in the geometry= line, preferring a pixel ratio of 4/3 to 3/2 (height/width).

I've not yet tried that myself, and now doubt that it would make an improvement in accurately representing the CRT image. The suggestion was based on calculations using a raster adjusted to fit most of the viewable area through the front panel in conjunction with the observation that the usual recommendation for a 3:2 aspect ratio of pixels does not look right.

Since then, anotherLISAguy measured an actual alignment graticule (a very rare service part) and we found that the "official" CRT adjustments put the aspect ratio of the pixels between 3:2 and 4:3, but closer to 3:2.

I've decided to give this another look. I can confirm that I need to turn 75R termination ON for the Lisa 1 and OFF for the 2/10.

Additionally, I've found that for my profile, the Lisa 1 requires a sampling phase setting between 0 (0 degrees) and 4 (180 degrees), while the 2/10 requires a sampling phase between 3 (135 degrees) and 7 (315 degrees). I've selected 4 then, an arbitrary choice from the two that overlap.

My profile, which I keep on the SD card at Saved_Profiles/6-12_BIT_YUV_Analog/Apple_/Apple_Lisa_.txt, is as follows:

sampling=4,4,4,4,4,4,4,0,1,0,5,0,0,0,1,4,0,1,1,0,64,256,256,256,39,256,256,256
geometry=156,9,720,360,720,368,2,3,1,1,20374338,896,5000,384,4,0,0
palette=Mono_(2_level)
scanline_level=0
Meanwhile, in the thread ried linked, we have

This setting for 8-bit analog YUV by user RolandJuno:
sampling=7,7,7,7,7,7,7,0,1,0,10,0,0,0,0,4,1,1,1,0,79,256,256,256,256,39,256,256
geometry=164,7,552,364,720,364,2,3,1,1,20374338,896,5000,379,4,0,0
palette=Mono_(2_level)
scanline_level=0
sigma7 recommends substituting 3,4 for 2,3 in the geometry= line, preferring a pixel ratio of 4/3 to 3/2 (height/width).

As it is here in this adaptation of the RolandJuno setting by ried:
sampling=7,7,7,7,7,7,7,0,1,0,10,0,0,0,0,4,1,1,1,0,79,256,256,256,256,39,256,256
geometry=164,7,552,364,720,364,3,4,1,1,20374338,896,5000,379,4,0,0
palette=Mono_(2_level)
scanline_level=0
Beyond the thread:

This variant is by DosFox, who made the first operational Lisa clone:
sampling=7,7,7,7,7,7,7,0,1,0,10,0,0,0,1,4,1,1,1,0,49,256,256,256,256,31,256,256
geometry=160,10,712,362,720,368,2,3,1,1,20368338,896,5000,377,4,0,0
palette=Mono_(2_level)
teletext_scaling=0
scanline_level=0
I wonder what the Adrian's Digital Basement variety is like?

Huxley,
If you want a replacement Dual Par Card, PM me and I will hook you up.
I put together some blue boards to demo the adapter I designed for the ESProfile at VCF midwest last fall and I still have a few around.  The adapter allows you to connect two ESProfiles to the Dual Par Card at the same time.
Rick

Ah yes, that's really good to know :-)
Someday stick the solder side into a flatbed scanner (or just snap a photo) so that we can have a squiz...

This is such a lovely and generous reply to this thread. Thank you for providing so much encouragement and knowledge here!

For context, this Lisa is the latest addition to The Retro Roadshow, the pop-up museum my wife and I created. We've just been booked for 2 (possibly 3) events this spring with an Apple theme, including one at a *very* prestigious venue. Having a functional Lisa to exhibit and share alongside some of our other notable Apple (and Apple-related) systems is obviously a pretty big deal. I'll definitely revisit this Parallel card but for now I'm just very excited that the machine itself is functional enough to exhibit!

One more detail before I forget: I did get confirmation that this Parallel card is a modern replica which was put together by the previous owner of this Lisa, and they apparently had some issues with it during the initial build that necessitated un-soldering and redoing the whole thing at least once. Good info to know!

Congratulations! This is good news.

You could replace the 2-port card entirely, but with every single chip socketed like this, you might have a great opportunity on your hands to learn and do some electronics troubleshooting at the component level, without all the hassle of soldering. (I'm assuming this isn't something you've done much of; I hope this is correct, and if not my apologies!) Obviously replacing the 'LS00 is necessary, but this might only bring you back to the point where you were before: a parallel port card that doesn't seem to work.

If you're interested, we could work with you as you go. If the problem really lies on the card (and it may not: could your Lisa motherboard have a problem? did the card come with the computer?), chances are that just replacing one or two chips will be all you have to do. Figuring out a fix like that can be mighty satisfying.

If it were just me talking to you (and maybe it is --- I can't volunteer others on their behalf!), I'd be inclined to go ahead by asking leading questions that might take you down roads I would take if I were troubleshooting the card. The hope would be that this could build some habits of diagnostic thinking that you could apply later. Of course I might also just embarrass myself: there are much better troubleshooters on this forum than me!

----

But before any of that: I think we should make certain that your card isn't going to cause trouble on the power rails even when you stick the card in correctly. If you have a multimeter, I would measure the resistance between the power pins on the card and the ground pins. PDF page 73 of the Hardware Manual shows you which pins carry power (note +5V, +12V, -5V, -12V, and +5V Stdby) and where to find ground (or "Digital Ground").

The card only uses +5V. If there is any less-than-infinite-basically resistance between any other power pin and ground, then that's not supposed to be there!

If the +5V to ground resistance measures quite low (perhaps in the teens of ohms or below), then something is awry, and we should work out what's providing such an easy path for current to flow from +5V to ground.

But if it's higher than that, then you probably won't have to worry about smoke again, provided the card always goes back in the slot correctly!

----

Now for a first leading question. Here is the schematic for the parallel port card. It will look very complicated if you're not used to looking at these things very much. But for now we don't need to understand it. I want to ask: there are 15 chips on this card (and five resistor packs, which look like chips but are just a bunch of resistors in a single package). Why did the 74LS00 at position 2F explode and not one of the other chips?

Note the PDF actually contains two copies of the same schematic, and each copy contains two very similar-looking circuits, because this is a two-port card. But the 74LS00, also called U2F because "U" means "microchip" and 2F is the location, only appears on the first sheet of each copy. It actually appears in multiple places for reasons we don't need to go into now. But observe what the U2F symbols are connected to... and now look back at the locations of all the power pins from the Hardware Manual. Why did U2F suffer so much?

QuoteI am back with a genuinely shocking + delightful update: Lisa lives!

...obvious signs of damage

Congrats!

The hole by the card edge fingers is where a mechanical stop should have been attached. If you attach one (strongly recommended), make sure it does not short out any of the gold fingers.

It looks to me that this is a reproduction rather than an original, but even an original could be missing the stop, so I suppose this is a caution to everyone to look over a new acquisition carefully.

It looks like the 74LS00 near C12 has a bubble on the surface, if so (rather than something stuck to it), that may indicate one of the points of failure (there could be more). Since it is in a socket (sometimes a major benefit of some reproductions!), you could remove it and sniff it separately.

I am back with a genuinely shocking + delightful update: Lisa lives!

As Stapleton suggested, I pulled the Parallel card out and tried again, and to my utter amazement she fired right up as though nothing was ever wrong in the first place. Incredible!

The Parallel card does have a pretty strong smoke smell, but I really can't see any obvious signs of damage. I'll attach a high-res photo of the Parallel card - perhaps someone with more electronics repair experience will spot something I'm missing?

On a very related note... anyone have a spare Parallel card they'd like to sell? 

EDIT: a kind person on Discord pointed out that the 74LC00 chip in position C12 (lower right corner) appears to have burst. I've ordered a replacement for a few bucks from eBay - fingers crossed!