KIM-1 repair advice wanted

[Dwight K. Elvey]

>From: ard at p850ug1.demon.co.uk
>
>> 
>> 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.

Hi Tony
 This is not totally true. I don't recall just what
it was but there are some mask options that are not easily
handled from the outside of the part. I just don't
recall what it was. I was looking at doing something
similar rather than pay about $120 to replace a sound
board on my Gottlieb Genie pinball machine.
 As I recall it was an inversion of one of the data port's
outputs as a mask option or something like that.
Dwight