LisaList2

Advanced search  

News:

2019.06.07 fixed NChat for the "Curve" theme, will eventually move it to its own page and add it to the default theme as well. Other plugins are next. see post in the Meta board for details

Pages: 1 2 3 [4]   Go Down

Author Topic: Another Prototype Lisa Card  (Read 1608 times)

blusnowkitty

  • Sr. Member
  • ****
  • Karma: +28/-0
  • Offline Offline
  • Posts: 75
Re: Another Prototype Lisa Card
« Reply #45 on: July 21, 2020, 08:59:26 pm »

Has anyone seen anything Applenet-related in this collection of auctioned materials? I am slowly beginning to investigate my Applenet cards again. It's probably an off-and-on thing, but it would be nice to have more hardware to make progress, particularly one of these hubs. I don't think it's very complicated inside.

I've been watching the guy's stuff since it first started showing up and I haven't seen any AppleNet cards unfortunately. If we can source a schematic or some internal pics of the hub, I can give it a best shot at cloning the PCB. Just wish I had another Lisa.
Logged
You haven't lived until you've heard the sound of a Sony 400k drive.

patrick

  • Full Member
  • ***
  • Karma: +28/-0
  • Offline Offline
  • Posts: 35
    • Patrick's Hardware Page
Re: Another Prototype Lisa Card
« Reply #46 on: July 22, 2020, 04:02:12 am »

If these Widex copies become more available in a public place (since the LisaList2 files section requires a login), I'll update https://github.com/stepleton/NeoWidEx#other-notes , which says there aren't any "readily available" copies today. :)

That should go to bitsavers.org, where all the other Widget- and ProFile-related stuff is. I was surprised not finding it there.


BTW: Tom was too polite to post a link to his AppleNet repository on Github. Many interesting stuff there!
https://github.com/stepleton/applenet
Cloning the PCB should not be too difficult, integrating it into LisaOS and maybe MacWorks might be a bigger issue.

The physical layer for AppleNet is a transformer-coupled differential signal, similar to EtherNet. That means the internals of the hub will be similar to a passive Ethernet hub. Pulse transformers and some logic to route the Tx signals from one port to the Rx of all others. The 10base-T physical layer patent should explain how this works.
« Last Edit: July 22, 2020, 04:13:18 am by patrick »
Logged

stepleton

  • Sr. Member
  • ****
  • Karma: +38/-0
  • Offline Offline
  • Posts: 103
Re: Another Prototype Lisa Card
« Reply #47 on: July 22, 2020, 05:00:45 am »

PS: as part of resuming my AppleNet investigations over the past couple of days, I've revisited the schematic and corrected a couple of errors, particularly around the network connector. I need to triple-check and re-upload those corrections; hoping to do that in the next week or so!

That network connector is an odd one---it's basically a DIN-7 with the top pin deleted. I was hoping to make a crossover cable for connecting my two network cards to each other, but I realised that I wasn't quite sure how they should work, and that's when I discovered the schematic bugs, and so on...
Logged

patrick

  • Full Member
  • ***
  • Karma: +28/-0
  • Offline Offline
  • Posts: 35
    • Patrick's Hardware Page
Re: Another Prototype Lisa Card
« Reply #48 on: July 22, 2020, 08:41:57 am »

In your current schematic ("2 years ago") you have pin 1 Tx-, pin 3 Tx+ and pin 2 GND on the transmitter side. The receiver side looks somewhat confunsing: you have pin 4 Rx-, pin 5 Rx+ and pin 6 GNDA. And there is a resistor from pin Rx- to GndA which I would expect at the transformer center pin. So this might deserve to be re-checked.

Nevertheless, connect Rx+ to Tx+ (transformer top to transformer top), Tx- to Rx- (transformer bottom to transformer bottom), and (any) Gnd to Gnd and it should work.

If this does not work just reverse + and - on one side. Polarity of the windings might not be reproduced properly in the schematic. This is difficult to see without unwinding the pulse transformers.


« Last Edit: July 22, 2020, 10:36:22 am by patrick »
Logged

stepleton

  • Sr. Member
  • ****
  • Karma: +38/-0
  • Offline Offline
  • Posts: 103
Re: Another Prototype Lisa Card
« Reply #49 on: July 23, 2020, 06:11:49 pm »

I've diagnosed the problem with my DMA test card: a broken trace, which I fixed.
https://photos.app.goo.gl/TkYWDHunxTMNLtHv9

Starting the Lisa now shows the card's boot icon, which is cute!
https://photos.app.goo.gl/376abXd45SacRPgY9

An attempt to boot from the card shows behaviour similar to what was observed for the I/O test card:
https://photos.app.goo.gl/Ms3inkRd7QdxNXfU9

The Error 90 is a strange one---that means "no card" according to the boot ROM source code, although it also looks like the value is never used by any of the code in the boot ROM! I think it's a red herring. Anyway, you can see parts of the same "WAITING FOR APPLE" message that the other test card had (and which we can see in that ROM dump I shared).
Logged

stepleton

  • Sr. Member
  • ****
  • Karma: +38/-0
  • Offline Offline
  • Posts: 103
Re: Another Prototype Lisa Card
« Reply #50 on: July 23, 2020, 08:23:00 pm »

In re the AppleNet card, I believe the attached image shows a more accurate description of what's going on around the network connector. You can see that the pinout of T1 threw me.

The pinouts of transformers T1 and T2 are still guesses---on the card they are mainly unmarked boxes with no ability to see inside. This evening I made measurements with an ohmmeter on the two AppleNet cards I own in order to figure out which pins were the centre taps. I'm basing my guesses on tiny differences in resistance, but this was remarkably consistent across both cards.

As Patrick noted, connections to pins 3,2 or 5,6 of the connector may need to be swapped, or perhaps even both pairs if the current arrangement puts the pulses upside-down on both sides. I'd like to hope that the it's not the case that a single pair needs flipping: if not, the plug has a nice rotational symmetry, and you can turn a crossover cable into a straight-through cable by flipping it upside down. (You would have to do something about the keying on the shell of the DIN connector, of course.)

The github repo with my schematic has been updated. There are one or two more things I'd like to check, so some additional updates may follow soon.

Unfortunately one of my AppleNet cards seems ill---it hangs during the boot ROM card test some of the time. The problem may be mechanical---it seems like sometimes it'll make it past the test if I flex the card during boot. I'm not certain of this, though.
Logged

blusnowkitty

  • Sr. Member
  • ****
  • Karma: +28/-0
  • Offline Offline
  • Posts: 75
Re: Another Prototype Lisa Card
« Reply #51 on: July 24, 2020, 09:25:52 am »

Here's something I just thought of: Has anyone tried booting their I/O and DMA (and maybe AppleNet?) cards in a Lisa 1, or at least a 2/5 with a 1 ROM? I'd be very interested to find out if all those cards are expecting something in the Lisa 1 ROM that was taken out for the Lisa 2/5 ROM and beyond.
Logged
You haven't lived until you've heard the sound of a Sony 400k drive.

stepleton

  • Sr. Member
  • ****
  • Karma: +38/-0
  • Offline Offline
  • Posts: 103
Re: Another Prototype Lisa Card
« Reply #52 on: July 24, 2020, 11:03:37 am »

Yes, my video was from a Lisa 1 :)

There is not much stuff in the cards' boot ROMs for a very different result, I don't think.

It might be interesting to see what it does when an AppleNet card is also installed. Perhaps it will wait for a test program to come in over the network. I will probably try this soon.


(edited to clarify which boot ROMs I meant.)
« Last Edit: July 24, 2020, 01:11:14 pm by stepleton »
Logged

stepleton

  • Sr. Member
  • ****
  • Karma: +38/-0
  • Offline Offline
  • Posts: 103
Re: Another Prototype Lisa Card
« Reply #53 on: July 26, 2020, 06:40:25 am »

To update: it looks like nothing different happens when an AppleNet card is installed.
Logged
Pages: 1 2 3 [4]   Go Up