torsdag 15 januari 2009

Mod's and add-ons

Some pictures of early modifications and add-ons:
- 8K memory (adding 4 k, 8 x 2114's)
- Extended video (32x48 characters, original was 16x48. Adding 1 k memory, some wiring and new decoding logic)
- The RUN-led (shows if the uP is executing or if its hangs, just like VAXes of the 80's! Yepp, I'm an old DEC employee....)
- The PIA adapter (parallell interface adapter, 6821. Connected to J1 directly, mods to IC17)

Other mods were:
- 600 baud cassette-speed (later retrograded to 490), switchable for printing
- RS232 interface (adding some components)
- SCART cable (the most recent mod, interfacing to TV-sets of today!)

Future mods would be:
- The uP running at 2 MHz clock (a Go/Nogo test...we'll see...)
- Getting rid of dark lines during scrolling (procedure exist on web)

1 kommentar:

  1. Wow, what a piece of pure nostalgia.
    The UK101 was my first computer and I spent huge amounts of time disassembling the BASIC, figuring out how it worked and entering pure hex bytes to add commands to it (I think it was tapping into some self modifying code executed at 00BCh - But might remember badly after all this time).
    I just wish I'd kept some of that work.