Ufff! Took me 2 weeks, but finally finished my combined RTC and banked RAM card. As usual I used prototyping PCB and point to point soldering using enameled magnet wire. I used this part of project as opportunity to enhance my workbench with better soldering tools - quality soldering station, better wire cutters, PCB holder, solder wick, chisel tips, you name it. The job was more enjoyable thanks to that. I had a little scare at the end because the card didn't work right away, but it turned out to be a missed connection. Fixed it and it works now. I am pleased with the result and I'm looking forward to design and implementation of the User Interface I/O card. (keyboard, display, joystick, sound, mass storage etc.)
Almost 300 soldering points - sometimes it is not fun. It is important to have good quality tools for this kind of work. I know, I am not good at it yet, but I am improving.
This PCB holder proves to be a very handy tool.
Ready to populate with IC-s and battery. Taking this opportunity to show off my new Hakko soldering station :-)
The card is in the mother board here, slot B2, working fine.
The test above shows that timekeeping and memory banking is working. Memory bank selection register is at address $C000, banked RAM starts at $8000. I also powered the computer down and back up and the RTC keeps the time. in a few days I will know if it is accurate.