[sdiy] SID 6581/2 source

[Rainer Buchty]

>Ebay!
>I got 4 C64's for 20$ 

*Working*? Then the prices must have dropped extraordinarily over the 
last years... (Ok, depending on which statistics you believe, there are 
up to 20 million C64 out there.)

Anyway, the C64 is also a great resource for DIY, in case you got a 
defective one (mostly related to a dead PLA or one of the RAMs having 
died). Apart from the SID you get

- videochip with up to 320x200 resolution (must be bus-master in a 6502 
  system; for other bus timings you need an arbitration logic); 
  unfortunately 15kHz timing, so no good with current monitors

- 2 I/O chips with serial line, timer, real-time clock, and 8-bit port. 
  Careful with this guy, it likes to die from static. Always buffer it.

- CPU with separate 6-bit port (useful for memory banking)

Rainer