Re: Crosspost: Did the cpu influence the display?

[The Wizard of Oz <wizard@emeraldcity.gov>]

On Mon, 26 Dec 2005 04:09:32 -0800, Bill H wrote:

<snip> 
> Relying on my memory and a cursory check on a number of websites it
> appears that the majority of Z80 cpu based computers had black and
> white displays, where as the majority of 65xx computers had a color
> display.
> 
> Now there are exceptions to this, but it makes me wonder, did the CPU
> influence the display?
<snip>

	There is something nobody has talked about yet. Possibly because it might
not have made it out of Winnipeg. M$ made a CP/M card for the Apple//. It
worked in my ][+, sort of worked with my //e clone, and wouldn't work in
my GS. It was intended to be a text only display using the Apple as a
display unit. I think someone locally wrote a unit for Turbo Pascal which
used the Apples memory to display HGR graphics. I took a look at the calls
and figured out how the author did it. The M$ card had a special routine
which allowed the programmer to directly access the Apples soft switches.
The RAM wasn't on the CP/M card. The card just rearranged the available
memory from the Apple and had a limited amount of RAM and I guess ROM to
replace what was used by the Apple. The memory was allocated and the unit
was a series of routines which built on the plot of a single point. It
still displayed graphics in colour.

	The whole process was slower than an Assembly program on the Apple, but
faster than Applesoft.

				Later
				Mike