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RE: [N8VEM-S100:6779] Reorder of S-100 8-slot Backplane PCB
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- Subject: RE: [N8VEM-S100:6779] Reorder of S-100 8-slot Backplane PCB
- From: "Bob Bell" <bbel...@gmail.com>
- Date: Wed, 22 Apr 2015 17:41:53 -0400
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Todd, I built one of your version 2 8-slot S-100 backplanes about 4 months ago, and I seem to recall offering some upgrade suggestions at the time. I cannot recall where I put my list, but let's see if I can recall the most important ones:
1. As you already have covered, the board thickness needs to be reduced. I had a h*ll of a time with the RNets. The leads just were too short and could not be soldered. I ended up building RNets from discrete resistors. Other components were also problematic, but not so much as the RNets.
2. One of the transistors has it's silk-screen mirrored. I had a heads-up on this prior to construction, so I made sure I put it in correctly.
3. The fuses are only protecting the LEDs. I'm sure that was an oversight, but there's no point to the fuses and I just put in jumper wires.
4. The 0.3" lead-to-lead pitch on the 1/4 Watt resistors is too narrow. I had to bend their leads very sharply to make them fit. I suggest they be 0.4".
5. The schematics are rather difficult to follow. If you want to send me your KiCad file for this, I would be glad to update it and show you how much better it could look.
If I think of anything else, I'll let you know.
From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Todd Goodman
Sent: Wednesday, April 22, 2015 8:48 AM
Subject: [N8VEM-S100:6779] Reorder of S-100 8-slot Backplane PCB
I'm now out of these PCBs (after shipping the last one to someone waiting for it.)
Before I reorder I have three questions:
1) Is anyone working on updates or a new S-100 backplane? I don't want to order a bunch and be stuck with them.
2) I know Don Caprio had two fixes and one improvement. I think things would work out much better if Don or someone else made those changes and updated the board files. If nobody else wants to do that then I'll make the attempt and run the changes past the list.
3) The last time I ordered the boards I ordered a board thickness of
0.126 inch. From measurements it seems to have ended up substantially thicker. I'm going to be reducing the thickness this time. If anyone has input about how thick to order (keeping in mind the finished thickness seems to be thicker than ordered) then please let me know.
Obviously, if anyone has any other input about the board then please let me know.
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