23 Apr
2007
23 Apr
'07
11:39 p.m.
On 23 Apr 2007 at 11:23, Allison wrote:
To run CP/M you don't need a lot but the minimal
and useful complete
system are not far apart.
Z80: Whatever you have!
RAM: 48-64k of ram 48k will be enough to run a lot of software, but 64k
is only 2 61256s (a 32kx8 SRAM). CP/M will run in 32k but limited
application software will fit. The only requirement is ram starts at
0000h and be contigious for at least 20K(minimum) after boot.
If I were to approach a project like this, I'd probably go find an
old junker credit-card or POS terminal that could be scavenged rather
than try to adapt one of the Z80s and peripherals that infest my
hellbox. Most of these things have lots of SRAM (128-512K) in
addition to flash or EPROM and a Z180/64180 or the like. You also
get an LCD display for debugging and a numeric keyboard. Just buffer
some data and address lines off for a floppy or IDE interface and
you're in business, as all of these things have serial ports already.
Heck, you could even adapt the flash on some of these things for use
as a mass-storage unit and skip IDE drive or floppy altogether.
But then, I'm basically lazy. :)
Cheers,
Chuck