S100 Board Template for KiCad

[Peter Sterrantino]

Hi All, 

I' not going to be able to make the Zoom call today, but wanted to drop a question for the group. Last weeks call had  lots of discussion on KiCad autorouters and layout first vs schematic first, which was interesting.I enjoyed the debate. 

I have been trying to get a Tarbell cassette interface card, but they seem to be pretty rare and expensive. I was thinking since they are so hard to find that I might build one. I've got a S100 protoboard and all the parts, and the schematic is in the manual, so I might give it a try. Question for the group... Do you think anyone else would be interested in a replica Tarbell? 

I'm debating building a hand soldered prototype first, or going straight to a Rev 0 PCB. I've designed a few PCBs before, but have used OrCAD or Altium. It seems like KiCAD is the choice of the hobby projects I see in the S100 and Altair google groups. I think I could pick it up pretty quickly. To make things easier, it would be helpful to find someone who has done a board before to copy the S100 board template (and maybe some component footprints). 

Does anyone have a KiCad S100 board template they would be willing to share?

I'd like to do a mostly faithful repro first, but update the easy stuff (74L to 74LS, etc.) and get rid of the infamous jumpers on the original. 

Curious what you all think.

Thanks.

Pete

[Joseph Corda]

Peter .. 
First I would be interested in such a board when you get it built !
I will be sure to bring your topic up in today's Zoom meeting as I would also like a S-100 template for kicad as well.

Joe

--
You received this message because you are subscribed to the Google Groups "Altair 8800" group.
To unsubscribe from this group and stop receiving emails from it, send an email to Altair-8800...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/Altair-8800/47cf6df2-1abe-481e-8e30-4cf2bd4e5edcn%40googlegroups.com.

[Peter Higgins]

S100 KiCad template:

https://avitech.com.au/?page_id=3240

John Monahan also provides the KiCad files for all the boards he has designed, from which you can also get an S100 template and many common component footprints. Just look up any of the new board designs at S100Computers.com .

You mentioned that you have already collected all the parts required to build a Tarbell cassette board reproduction. Some of these parts are no longer easy to find. You may be interested in this discussion in the S100Computers Google Groups forum started by Steve Mastrianni, who (at the time) was also interested in designing a reproduction:

https://groups.google.com/g/s100computers/c/qCLZviMBAP4/m/woaT7e2SAQAJ

[Peter Sterrantino]

Hi Peter, 

Thanks for this. I’m relatively new to these forums so was unaware of Steve’s previous efforts. I’ll check in with him… 

I did look at the thread and there was some very helpful information there. I was able to source the 8T20 (Anchor Electronics) and the DM 8131 (eBay - 4 for $12), but I fell into the same 74L86 vs 74LS86 mistake. I now have 10 of them 😁.   Must have gotten dumb cause I thought I checked the output of each gate for fanout and LS compatibility. And was completely unaware of the different pinout, so thanks for that. 

Looks like the 74L86 is going to be hard to find…. I don’t see it in my usual sources. I’d be curious about Steve’s experience and if he did use the 74LS86, but with the adjusted pin out. If I remember my logic, right, the LS stands for low power Schottky, And I thought that was just Schottky diodes in the input stages of the gate. I have to dig into some old data sheets and see if the output stages are similar enough between the families.

I work with a guy who is a long time ET and has a fair collection of old ICs. I’ll also check with him. 

Curious if anyone has a real Tarbell and can show me a scope shot of that U30 output so I can compare. I’m guessing the RC network after U30 does some smoothing of the square wave for audio purposes, so maybe not that critical? 

Again, thanks for the tips!

Pete 

--

You received this message because you are subscribed to the Google Groups "Altair 8800" group.
To unsubscribe from this group and stop receiving emails from it, send an email to Altair-8800...@googlegroups.com.

To view this discussion visit https://groups.google.com/d/msgid/Altair-8800/2f9f1489-3c57-4e3b-8d6b-8bd17fb7d08dn%40googlegroups.com.