Anybody with experience with the TMS9911 DMA controller?

[pnr]

I'm aware of only one (publicly available) design that incorporates the TMS9911 DMA controller, and that is the Powertran Cortex.

 

In particular I was wondering about its clock input. In the Cortex design this is hooked up to the *inverted* CLKOUT signal of the 9995 CPU. From studying the data sheet, I see no particular reason for this inversion. The datasheet does refer to this input as inverted ø, but that is probably because it refers to the inverted ø1 output of the TIM9904 or the inverted ø3 output of the TMS9980/9981 as possible sources for this signal.

 

Does anybody know of other (public) designs using that chip, or have experience with it?

 

[Stuart]

(Major digression - here's a chap who apparently helped to design the 9911 - https://www.linkedin.com/in/longley/. He also claims to have done the product definition for the TMS9909 floppy disk controller, and that that chip was in full production for 8 years. For a chip that was produced for so long, it is mighty hard to get hold of one, and I don't think anyone has seen one that isn't the 'TMX' prototype version.)