UPNOD CARD0117 TN64
This repository contains all the knowledge I could gather about a vintage, 80-ies TelCo card marked CARD0117 model TN-135:
- ROM dumps
- Reverse-engineered schematics
- VHDL models & simulation results
- Datasheets of old chips
Complimentary commentary can be found on my blog.
The card appears to have been modded at one point. It's factory marked as TN-104 (despite the actual PCB being marked TN64), but that has been crossed-out and marked TN-135 with a faint marker. The aboundance of blue mod-wires seems to support this.
Ok guys, I think the EEPROM works, let's program this thing.
Top ROM chip's contents are amusing:
00000ea0: 0a0d 5448 4520 5155 4943 4b20 4252 4f57 ..THE QUICK BROW 00000eb0: 4e20 424f 5820 4a55 4d50 5320 4f56 4552 N BOX JUMPS OVER 00000ec0: 2054 4845 204c 415a 5920 4652 4f47 0a0d THE LAZY FROG..
Just use the leftovers, she'll be a'ight.
Some logic gates on the board are used in a sub-optimal way (either combined into another logic gate, or with signals travelling to the other side of the PCB and back). Most likely due to space/money constraints.
I find the idea of Full-Full-Stack Development (FE downto metal) appealing, so I've started making some lateral movements towards it. Also, computer archeology, what's not to like?