1 Jun
2013
1 Jun
'13
3:31 p.m.
On 2013-05-31 20:50, ard at p850ug1.demon.co.uk (Tony Duell) wrote:
I asusme you have a dump of the boot ROM? If not I think I can find it.
Have you looked at the hardware and the system tracks on the disk? This
thing, for all it claims to be the disk drive for the HX20, etc, is
actually a full Z80-based computer running something very close to CP/M
(!). I often wonder how hard it would be to use it as such (there's a
second serial port too, if you need it).
Yes. fasinating. I am trying to disassemble it, but started with the
boot ROM. The TFDOS as it is called, will be next. As it has everything; enough RAM, disk controller,
serial port, there
should be no reason why it should not work. I might try it, maybe even
before retirement ;-). With the information in "The Programmer's CP/M
Handbook" it should be no problem.
It should eb fairly easy. There's absolutely nothign custum on there. All
standard chips, easy to get data sheets for them. A schematic exists, so
figurign ot uthe addresses of the I/O devices is not hard either.
I have never looked, there is that second serial port at TTL levels (th
TXDB and RSDB piads on the serial daughterboard). Does anything ever come
out of there in normal operation?
-tony