[Techtoolslist] Finally - a use for the TMS9900 pod!

[Mike Coates]

As far as I can remember Looping uses one.

there may have been 1 more, but cannot think of it at the moment.


 From pinout the CRTC looks like a 6845 (rather than the TI one ...) -
usually has the markings removed, along with the 9981

Don't forget the 9981 fetches words as two 8 bit reads, where the 9900
reads all 16 bits at once.

p.s. did you sort the S2650 adapter, did grounding that pin work ?

Mike

On 01/07/2024 03:03, John Robertson via Techtoolslist wrote:
> It turns out that Universal used the TMS9981 CPU in Cosmic Guerilla -
> someone sent the board to me to service. I haven't checked if there are
> any other Universal games that ran that CPU.
>
> Interesting that TI reversed the order of the addresses and Data lines
> from what is now the convention. Their D0 is most folks D7! Our A0 is
> TI's A13 on the 9980/81...
>
> Need to see if I can make a simple adapter 9900 <--> 9981, unless
> someone made one and is willing to sell me a copy...
>
> Thanks!
>
> John :-#)#
>