[Coco] Am9511 Arithmetic Processing Unit Cartridge Pak for the Color Computer

[Don Barber]

Sorry, I should clarify. I should say I did not design my Pak to have 
direct memory access.

Evidently it is doable to pair the Am9511 with a DMA controller to do 
such, as described in figure 7.5 of the APU manual (Page 45 of 
https://raw.githubusercontent.com/barberd/coco9511pak/main/docs/Am9511A-9512FP_Processor_Manual.pdf). 
But this design is for the 8080.

I don't recall seeing any add-ons to the CoCo for DMA (other than the 
VDG doing that by design); I'd think the SAM/GIME would get in the way 
of such? Maybe something could be hacked together by sending the HALT* 
line high and doing direct memory manipulation?

Anyone have access to IEEE publications? 
https://doi.org/10.1109/MM.1981.290914 
<https://doi.org/10.1109/MM.1981.290914> might be interesting.

Thanks,

Don

On 3/14/23 19:06, Don Barber via Coco wrote:
> No, the Am9511 does not have direct memory access. Think of it like a peripheral that you need to read from and write to.
>
> Thanks
>
> Don
>
> Sent from my iPhone
>
>> On Mar 14, 2023, at 6:51 PM, Steve C. via Coco<coco at maltedmedia.com>  wrote:
>>
>> Does it speed bit block transfers throughout memory? That might make for
>> things like smooth scrolling.
>>
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>