Computer Kit / Plans

From: Richard Erlacher <richard_at_idcomm.com>
Date: Mon Sep 18 20:37:40 2000

Well, with no eprom programmer, I'd say that might be a good place to start.
If you get a set of programming spec's for the EPROMs, EPROM-based MPU's,
and EEPROMs, not to mention FLASH memory devices, that interest you, perhaps
the thing to do would be to build a programmer using a PIC, SCENIX SX, or
whatever you choose. The easy way to interface such a device is thorugh
the parallel port, which has several operating modes, of which I like the
EPP the best, but you can make up your own mind. Keep in mind, that you're
building a tool that you're going to use again and again. Keeping it
flexible might be a real priority. Most programmable parts are VERY easy to
program by comparison with parts dating back to the '80's, and the 2716, in
my opinion, was of all of them the easiest. There are few MCU's easier to
program than the 8748, though you'll have a tough time finding them outside
a scrapyard. Frankly, once you get past the notion of fiddling with
voltages high enough to damage some of your circuitry if it gets where it's
not wanted, you'll find this sort of thing quite straightforward and even
fun.

One advantage to using an SX, is that it's so fast you can use it to perform
pretty accurate timing of the controls on a field programmable part. Whats
more, if the code burden to waste time or synchronize with an external event
is awkward, you can switch the clock speed with a programmable timer, though
you need to take into consideration what that does to the internals, e.g.
timer/watchdog, etc.

Let me know what schematic format(s) you can read and I'll see if I can
generate one of more of them.

Dick



----- Original Message -----
From: Kevin Stewart <stewart_kevin_at_hotmail.com>
To: <classiccmp_at_classiccmp.org>
Sent: Monday, September 18, 2000 5:19 PM
Subject: Re: Computer Kit / Plans


> Well, at first I was thinking I'd look for a kit... but now I'm thinking
> more of starting from scratch. I'd love to look at the plans you have for
> the S100. I have both Z80 and 8085 chips in my collection (at one point a
> friend gave me a Sears parts drawer filled with ICs... there are tons of
> obscure little parts in there, including several processors).
>
> I plan on learning Z80 and 6502 at some point in my lifetime... so I'd
like
> to take a look at both schematics.
>
> I don't have an (E)EPROM programmer at this time.
>
> Thanks,
> Kevin
>
>
Received on Mon Sep 18 2000 - 20:37:40 BST