Re: Apple and the Holy War

[Roy and/or Janet Miller <millers@inetnebr.com>]

David Empson wrote:

>
> 6801 is a single chip microcomputer, with built-in ROM, RAM and some
> peripherals (serial port, parallel I/O, timer).  It also has CPU
> architectural improvements such as the D register and associated
> instructions.
>

One of the interesting things about the Coleco ADAM was that keyboard,
printer, tape and disk drives were controlled by 6801s, and the ADAM had a
"master" 6801 which shared the Z80's memory space, and it controlled all the
I/O of the computer, thus freeing up time for the Z80 to do it's thing.
Something similar happened in video, because the ADAM used TIs 9918a (or was
it the 9928?) video processor with its own 16k of RAM. The ADAM needed all
this help too, because it did all of it's programs in graphics mode. Unless,
of course, you ran it under CP/M :)

Roy