5 Aug
2007
5 Aug
'07
9:29 a.m.
On Saturday 04 August 2007 17:42, Tony Duell wrote:
Agreed.
Thanks for all
the information everyone. I'm really looking into
everything now, as far as building a computer from an off the shelf CPU
such as a Z80 or 6502. One thing that has occurred to me is that I will
likely need an EPROM Burner. Where can I get such a device for a modern
PC?
IMHO, more important than the EPROM programmer is an EPROM emulator. This
is a box of RAM that connectes to the EPROM socket of the target system
(the board you'be just made) and also to a host machine (PC, parallel
port, serial port, USB?). YOu can quickly download perogams into the
emulator, which then appears exactly as the EPROM does ot the target, and
the latter can therefroe run said programs. The advantage over using EPROMs is that you can
re-write the RAM as many
times as you like (EPROMS have a limited number of program cycles) and
rewrite it quickly. Unless your programming is a lot better than mine,
you will go mad if you have to wait 20 minutes for an EPROM to be erased
and reprogammed. each time you want to make a change!
Unless you have a pile of EPROMs handy... :-)
There have bnen seceral desings for such devices in
Elektor magazine over
the years (and I guess elesewhere). The one I put together (using the
Elektor PCB) was just a handful of TTL parts and a couple of 32K SRAMs.
It links to a PC parallel port (which downloads bytes into the RAM).
I remember seeing one magazine article for such a device, but I wasn't that
thrilled with the design of it. It used some sort of counter chips to step
through the addresses of the target RAM, and wasn't very flexible in its
approach to things.
I started giving some serious thought to building one of those boxes, but
never did finish it.
Do you know of designs on the web?
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin