Hand-rolling a CP/M machine

[Allison]

>
>Subject: Re: Hand-rolling a CP/M machine
>   From: woodelf <bfranchuk at jetnet.ab.ca>
>   Date: Wed, 25 Apr 2007 13:24:17 -0600
>     To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>
>>> You can copy the screen logic for TRS80 as that is a basic 64x16 as well.
>> Good thing to keep in mind.
>
>Well if anybody is doing VDM-1's the big problem is that you can't find
>the Character ROM any more. I like the idea of TTL display like VDM-1
>but since this is not the late 70's a 80x24 screen is reasonable
>and the data out is a simple VGA format, since the monitors are easy to
>come by.

You have to be kidding me.  All you need is a 2764 and a programmer.
It's a ROM and the pattern is in the manual, what could be easier?
Actually if someone were building I'd suggest using a 2764 over the
part used on the VDM1 as that was a two or three voltage part and 
27C64(or even a 27C256) is common as flies plus lower power.

Allison