Hi Everyone
I joined the forum a couple of weeks ago proper as I got stuck on 6522 decoding - and got an answers so quickly and accurately it was awesome.
Anyway, as little gesture of giving back, I thought I would post you my project link (it's on hackaday.io) so you can see how the project is coming along. Happy for any advice, ideas and feedback.
I've been building my homebrew for about 11 months now in the current incarnation. I started very small and simple getting a 6502 to free run etc. The information and links on 6502.org were invaluable and inspiring!
I've made reasonable progress considering I do the odd evening or weekend. The hardware is basically done:
- WDC 65c02 running @ 2.68Mhz
- 44KB addressable RAM
- 8x0.5KB IO space
- 16KB ROM
- 2 x WDC 65c22 @ 2.68Mhz (used for software driven SPIO interface to SD Card, BBC keyboard interface, 8910 interface)
- CMD 6551 ACIA for serial IO
- TMS9918 VDP
- AY-3-8912 for sound and Atari compatible joystick interface
- All done on breadboard, then placed in a BBC micro case (sadly, had to junior hacksaw it to fit the breadboards!)
Now the focus is mainly software:
- Have built my own FAt16 routines for load, save, del of files on SDCard
- Serial input / output routines through a 6551
- Keyboard driver for BBC keyboard (full function, kind of)
- Screen driver routines (text only at the moment)
- Monitor software (memory dump, set, etc.)
The next software challenge now is to design and implement a ROM based interpreter, just like the home micros of the 80s (e.g. Oric, Atari, CBM, BBC).
Thanks again for the help to sort out my hardware issue - it was a silly error, but needed that independent set of expert eyes to spot!
Cheers, Dolo
https://hackaday.io/project/5789-6502-homebrew-computerP.S. I did try and get this link added to the list of projects, but seemed to get a bounce from the webmaster..