Messing Up

A project log for Commodore CHESSmate Reproduction

The plan is to make a reproduction of the dedicated chess computer CHESSmate released by Commodore in 1978.

michael-gardiMichael Gardi 02/26/2024 at 17:374 Comments

I'll admit that when I get close to finishing a project I can get a little careless. That was the case when I sent the CPU backpack daughter board in for fabrication. There were two issues.

  1. The footprint that I used for the ESP-32 WROOM development board was wrong. The two rows of 19 pins were 2.45 mm too far apart.  No excuses, I usually print a PCB layout on paper when done and set the parts on top to check this. This time I did not and got burned. I love the ESP-32 but I get that distinct impression that there is a lot more variance between boards than there is in the Arduino world. Be careful.
  2. Worse perhaps is that I reversed the VCC and GND lines going to the CHESSmate PCB header. If this was the only problem I could have salvaged the boards with a couple of trace snips and some jumper wires, but with the pins offset wrong there's no point.

At any rate here is the fixed PCB that I just sent off for fabrication.

Sigh. At least I was able to add a power header to the board that I missed in the first version.


Cees Meijer wrote 02/29/2024 at 09:48 point

Yes, this happens. Sometimes the ease and speed at which you can have PCBs made is a curse ;-) ( Remember the days when you had to create the layout using black tape and it took 2 months to produce single board...?)

  Are you sure? yes | no

Ken Yap wrote 02/29/2024 at 10:43 point

That's one advantage of being cheap like me. I check carefully because it's a 2-3 week turnaround. 😛

  Are you sure? yes | no

Michael Gardi wrote 02/29/2024 at 16:04 point

My turn around is usually 7-10 days but that's because I'm too impatient to wait and usually pay a premium for faster shipping. For instance these small PCBs cost $2.71 for 5 but shipping was $25.23. 

  Are you sure? yes | no

Michael Gardi wrote 02/29/2024 at 15:58 point

Oh the good old days...NOT. 

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