This is COLE-1, my first 6502-based SBC. The name doesn't stand for anything; I just needed a name and decided to name it after my late cat.
Specs:
WD65C02-14, originally clocked at 2 MHz but currently running stable at 4 MHz
WD65C22S VIA, running a jiffy timer and both ports brought out to headers for future expansion
MC68B50 ACIA connected to TTL serial running at 115.2 kbps
62256-70 32K RAM
AT28C256-12 32K EEPROM (30K usable owning to taking a chunk for I/O space)
MAX1232 for reset circuit and watchdog timer (though i ended up disabling the watchdog by clocking it from Phi2; I wanted my VIA pin back)
All of the discrete components except for a BAT85 diode are 0805 surface mount components on the back of the board.
I went with the 6850s because I have a dozen or so of them in my personal stock, from when I was buying up parts with plans to build one of each of Grant Searle's SBCs. The MAX1232 was kinda overkill too once I disabled the watchdog, but I already had them so I went with it.
The schematic and PCB layout were done in KiCad. It's a 100x100mm 4 layer board, fabbed by PCBWay. In retrospect I probably could've squeezed all this onto two layers, but I wanted the ground plane, and I also was kinda anxious to try a four layer design.
The funky contraption in the lower left is because I messed up doing my layout, and didn't realize that I'd picked a 10mm wide footprint for the ACIA instead of the normal 15mm footprint. Rather than toss out otherwise perfectly good boards I rigged up a converter with some single-row headers and double-sided perf board. It's ugly, but it works, and needless to say I will not be making that mistake again! I should've printed out the layout and did a test fitting, but my ink jet printer is still disconnected to make room for my 3D printer.
I had a lot of fun designing and building this; I've wanted to build my own custom computer since I was a young kid. I learned a great deal along the way, largely thanks to all the posts by everyone on this forum. Going forward I am going to be experimenting with adding video and sound to this SBC, and also start doing some preliminary work on COLE-2, which will be 65816-based.