General Category > LisaList2
Another Prototype Lisa Card
blusnowkitty:
--- Quote from: stepleton on July 21, 2020, 06:35:11 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.
--- End quote ---
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.
patrick:
--- Quote from: stepleton on July 21, 2020, 06:35:11 pm ---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. :)
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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.
stepleton:
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...
patrick:
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.
stepleton:
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).
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