KIM-1 repair advice wanted

Tony Duell ard at p850ug1.demon.co.uk
Fri Oct 7 14:46:21 CDT 2005


> 
> On Oct 6 2005, 22:03, Tony Duell wrote:
> > > fear it's more likely a 6530, and I assume they're unobtanium.  Has
> > > anyone ever come up with a kludge to effectively use a 6532
> 
> > My Commodore 8250LP disk drive has an official kludgeboard in what
> seems
> > to be a socket designed for an 6530. It contains a 6532, a ROM, and a
> > simple TTL chip ('04 or something like that).
> 
> Sounds like a start.  I obviously can't get this fixed for, er, today,

Argh, I misremembered it :-(. I've found the schematic I traced out. It 
contains a 6530 (not a 6532), a 2716, and a 74LS04.

The 6530 pins are wirrd to corresponding pins on the header, apart from 
RS0/, which is tied high (to disable the internal ROM of that chip). The 
2716 A0..A9 go to the corresponding header pins, A10 is grounded. D0..D7 
on the 2716 also go to the obvious header pins. OE/ goes to RS0/ on the 
header. CS/ is Phi_2, inverted by one of the gates in the '04.

 I don;t know if you could do a similar thing with a 6532, I think you 
could. At least this would let you use any 6530 with the appropriate 
chip-select polarites, no matter what was in the ROM.

-tony


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