Page 1 of 1

Gigatron schematics error?

Posted: 22 Jul 2019, 15:41
by maca134
Hey, first post, so id like to say hello!

Been mess around recently with DIY cpu's etc and came across the Gigatron and decided to give it a shot building it in Logisim.

After look the schematics here: https://cdn.hackaday.io/files/207818890 ... matics.pdf, I started on making the ALU (as the multiplex approach is pretty interesting).

It looks like the pins on the top 4 bits (U17-U20) look like they may be abit backwards. After building the thing in logisim, things did not make sense with the top 4 bits (bottom 4 bits worked fine).

https://dl.dropboxusercontent.com/s/qvv ... b7a928.png

I could be completely wrong, im a programmer and not an electronic pro.

Moved from "Kit assembly" by moderator.

Re: Gigatron schematics error?

Posted: 26 Jul 2019, 21:17
by marcelk
It makes sense on the PCB. I wouldn't follow the same layout in Logisim :-)