Date   : Mon, 29 Dec 2008 00:36:33 -0000
From   : jumbos.bazzar@... (Mark Haysman)
Subject: OT: ZX80 ROM ?

> Mark Haysman wrote:
>> Oops, just need to correct myself there, the TMS2532 has A11 on pin 18
>> instead of 21 compared to a 2732, and some other programming/select pins 
>> are
>> messed with. But according to the diagram I have for the ZX80, the 2732 
>> is
>> the correct type.
>>
>> If for some reason my diagram is wonky, and you DO need a TMS2532, then 
>> let
>> me know, I've got those as well.
>
> I have the actual sinclair ZX80 assembly instructions here (paper based
> no less), and on the component list, it lists IC2 (the rom) as 8232 or
> TMS4732. The circuit diagram also has A11 on pin 18, CS on pin 20 and
> A12 on pin 21, note this is a mask programed rom, so doesn't need a
> programming pin so can have an extra address line. This is the pin I
> needed to cut on my board.
>
> Just found the assembily instructions on the web here :-
>
> http://www.zx81.de/english/zx80_e.htm
>
> I have seen a re-drawn schematic for the ZX80 that does list a 2732, so
> that may be the one you have seen.

Yes, it is a redrawn one I've seen, tsk tsk mod the diagram but not say 
anything about it is naughty...I'll set Robot Santa on it's creator...

Pin 21 doesn't seem to do anything according to the datasheet, apart from 
the programming function. The Sheet also says the TMS2532 is compatible with 
the TMS4732 ROM, so it sounds like that's the one that Rob might need. On 
the diagram it's marked as "CS2", so maybe it's not important?

Rob...if you want to get in touch again and confirm that you do need a 
TMS2532, I'll do you one with the same code.

Mark.