[Coco] [Color Computer] Re: POKE 65495,0

[James Diffendaffer]

--- In ColorComputer at yahoogroups.com, "James Diffendaffer"
<jdiffendaffer at ...> wrote:

>

> 

> >> Could it even be that different production runs of the SAM have

> >> different behaviors?

> >>

> >> JCE

> >>

> >

> >There was a second generation of the SAM chip called 74LS785 that I 

> >think appeared in the

> >Coco2. One of its main features was to extend the refresh counter from 

> >7 bits to 8 bits. This

> >allowed the usage of 64Kx1 dram chips. Since I don't have a spec sheet 

> >on the 74LS785, so

> >I can't verify that any other functions have changed. From what I have 

> >read the 74LS785 is

> >pin for pin compatible with the 74LS783/MC6883.

> >

> >james 

> 

> Actually, I think the newer SAM included a built in latch to reduce

> the motherboard parts count.  I don't think the pinout would change

> much but it would function differently.


Or was it the new version of the VDG that added the latch... not sure.