Memotech MTX 512
Petteri Jäntti
Has anyone had any in-depth experience with Memotech's machines? I have
a MTX 512 non-disk unit. The machine has also been available with floppy
and/or hard disk configuration (although as I recall, that version had a
separate box for the computer and a separate keyboard. Mine is the 'all-in
one' version with the RF modulator. I was wondering if this machine could
utilize the CP/M supplied with the disk system. There were some other
differences besides the disk controller. The disk units had 80 column
cards and also 1 channel sound (as opposed to the 3 channel version in
this version). Didn't the disk units have the same TI sound chip? Am I
having a wet dream thinking it wouldn't be too hard to run CP/M on this?
Any one has any appropriate technical documents for the MTX?
-Petteri "piling up the old antique until my home is saturated" Jantti
--
Petteri Jantti ! e-mail: p...@ichaos.nullnet.fi
Hirsipadontie 3 E 25 !
FIN-00640 Helsinki, Finland ! "Bell Labs Unix -- Reach out and grep someone"
Jan Bredereke
: Has anyone had any in-depth experience with Memotech's machines?
I still do run a MTX500/FDX system.
: I have
: a MTX 512 non-disk unit. The machine has also been available with floppy
: and/or hard disk configuration (although as I recall, that version had a
: separate box for the computer and a separate keyboard. Mine is the 'all-in
: one' version with the RF modulator.
There are several versions:
- a basic BASIC version: MTX500 with 32k Memory, which can be upgraded
to 64k; or MTX500 with 64k on board.
- And additional FDX box with one or two disk drives, a CP/M boot prom
and an 80 column card. It can be used with BASIC too, but it is more
sensible to run CP/M on it. It needs 64k, of course.
- The reduced SDX version, which is plugged in the left side of the
MTX and contains a single drive. As far as I know, it was not very
successfull.
CP/M was included with all the disk versions.
Until last year or so, there was a very lively user group here in
Germany, which did a lot on hardware and software support.
There was even a Finnish member. :-)
Because of this support, my machine now has:
- .5M main memory
- .5M SRAM disk
- 1M DRAM disk
- 3 floppy disk drives
- A Bios that supports (at least) 1M main memory
- ZCPR3 command processor replacement
- ...
If you want to upgrade your machine to CP/M, I could provide you
with some addresses of people who probably still stock some parts.
: I was wondering if this machine could
: utilize the CP/M supplied with the disk system.
So, why not? Just just need the FDX disk box and the software.
: The disk units had 80 column
: cards and also 1 channel sound (as opposed to the 3 channel version in
: this version). Didn't the disk units have the same TI sound chip?
The 'sound' on the 80 column board actually is just a 'beep' for
the ASCII bell character. But you can still use the sound chip on
the mainboard.
Good luck,
Jan
--
Jan Bredereke E-mail: bred...@informatik.uni-kl.de
Universitaet Kaiserslautern, FB Informatik Tel. : +49 (0)631 205 3287
Postfach 3049, D-67653 Kaiserslautern Fax : +49 (0)631 205 2640
Bernd U Meyer
>Has anyone had any in-depth experience with Memotech's machines? I have
>a MTX 512 non-disk unit. The machine has also been available with floppy
>and/or hard disk configuration (although as I recall, that version had a
>separate box for the computer and a separate keyboard).
You got yourself a wonderful piece of hardware here! But let me first
correct one misconception: The floopy/harddisk was an add-on that, yes,
came with a new, big box, a new power supply, an 80 column card, serial
connections (I believe) and a new sound system. But you could still use the
original, nice MTX-512, and there was a CPM program with it that allowed you
to switch all the extra stuff off and do MTX basic ( or NODDY, or assembler,
or whatever you liked) on the RF output.
>Mine is the 'all-in
>one' version with the RF modulator. I was wondering if this machine could
>utilize the CP/M supplied with the disk system.
It can - but only if you get the disk controller. I used to have a diskless
MTX, but then IBM (yeah, _that_ IBM) destroyed it and had to buy me another
one, but this was far after Memotech had folded up, so I dug up a used one
that fortunatly included the disk controller. I had it run for some time,
and even started WordStar, but then I got my first "real" PC and got fed
up with the old system. This might be due to the fact that my old trusty
MTX was heavily modified whereas this new one was just plain boring (and
slow, that is :-)).
The best thing about those beasties was the complete circuit diagram at
the back of the manual, plus the fact that nearly everything was just plain
74xx logic. They were really hard to kill, and even if I killed it, well,
no prob, just replace the chip. Of course, the errors got more subtle once
I had put a Hitachi HD64180 CPU, static RAM, a shared memory connection and
some more logic on an extra board, but intimate knowledge of the machine and
carefull tapping of the wire chaos always got it running again....
I remember one day when we were showing our home-built multiprocessor system
on the Hannover Messe in Germany, and I had forgotten the power supply for
it, we just hooked up four processors to the MTX's power supply (the MTX
was used as an intelligent communication processor), and though the RF signal
was lost everytime all 4 processors had their status LED on "ON", it worked
like a charme. Ah, yes, that was the same day I became really frustrated
because after setting up the system, the MTX wuld not work, and the usual
patting did not help. Took me about an hour to find out that it actually
_did_ work, but that the video chip (which was then in a low cost socket,
but not for very much longer :-) had a bad contact....
>Am I
>having a wet dream thinking it wouldn't be too hard to run CP/M on this?
I'm not sure, but I don't think I have the disk controllers circuit dia-
gram, and without that, it will be pretty hard. If you are really serious
about this, get back to me in about a year, I'll be back with the machine
by then and can dig through whatever I find. Right now, it would cost you
abot $1000 to get me to that machine :-)))
>Any one has any appropriate technical documents for the MTX?
As I said before, the complete circuit diagram was included in the manual,
as well as a good description of the video and the sound chip and other
IO ports. The description of the Z80 peripherals is not that good, but then
those are standard parts and information is easily obtained from other
sources. If you want me to, I can copy this for you next year....
Bernie
P.S.: I have fond memories of that machine, and would use it anytime again
to control some homebuilt stuff.
P.P.S.: Email adress next year: ro...@umibox.hanse.de
--
"And the band played 'Waltzing Mathilda' / as we stopped to bury our slain;
And we buried ours / and the Turks buried theirs | ..... living in Oz ....
And it started all over again" |
(The Pogues, "Waltzing Mathilda", orig by Eric Bogle, "And the band played WM")
Stephen Usher
Bernd U Meyer <ber...@cs.monash.edu.au> wrote:
>The best thing about those beasties was the complete circuit diagram at
>the back of the manual, plus the fact that nearly everything was just plain
>74xx logic. They were really hard to kill, and even if I killed it, well,
>no prob, just replace the chip. Of course, the errors got more subtle once
>I had put a Hitachi HD64180 CPU, static RAM, a shared memory connection and
>some more logic on an extra board, but intimate knowledge of the machine and
>carefull tapping of the wire chaos always got it running again....
>
Seeing that you seen to be the resident MTX hardware techy on a.f.c I wonder
if you could point me in the correct direction with my poor sickly MTX500.
Cause of the problem:-
I was using my MTX as a terminal to an Atari ST using the MTX communications
board when suddenly it hung. Upon power-cycle nothing.. zippo, no output
from the RF, nothing.. The power supply checks out. Oh well.
Any ideas? I'd love to get the old machine back running again, it's the only
machine in my collection no longer running.
Steve
PS. My collection so far:-
ZX81 (Issue 1 PSB, Issue 2 ROM) + 16K RAM pack.
ZX Spectrum, originally 16K, now with 48K RAM & Speccy + case (official
upgrade version) with interface 1 & two microdrives.
Memotech MTX500 + communications board (dead)
BBC-B + DFS & 40/80 track switchable double sided 5.25" disk drive.
Sinclair QL + Trump Card & twin 720K 3.5" floppies.
Atari 520STM + 2.5MB RAM, Atari 720K external disk.
Atari TT030/8 + Third Coast Technologies 85MB HD, external 3.5" disk & SCSI
ethernet box.
Sun 3/80 with internal 424MB hard disk, floppy and bwtwo frame buffer, 16MB
RAM.
Now, if I could get an old 380Z with 256 colour graphics board.... and an
MK14.... and... :-)
--
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Computer Systems Administrator, Dept. of Earth Sciences, Oxford University.
E-Mail: st...@uk.ac.ox.earth (JANET) st...@earth.ox.ac.uk (Internet).
Tel:- Oxford (0865) 282110 (UK) or +44 865 282110 (International).
Stephen Usher
Petteri Jäntti <p...@ichaos.nullnet.fi> wrote:
>
>
>Has anyone had any in-depth experience with Memotech's machines? I have
>a MTX 512 non-disk unit. The machine has also been available with floppy
>and/or hard disk configuration (although as I recall, that version had a
>separate box for the computer and a separate keyboard. Mine is the 'all-in
It was merely an expansion box connected to the keyboard/CPU via a ribbon
cable.
>one' version with the RF modulator. I was wondering if this machine could
>utilize the CP/M supplied with the disk system. There were some other
I doubt it as the expansion box had some extra electronics such as
serial ports (though you could get an extra board to fit inside the
MTX5{00,12} which I had). Also, CP/M would need a disk controller card.
>differences besides the disk controller. The disk units had 80 column
>cards and also 1 channel sound (as opposed to the 3 channel version in
>this version). Didn't the disk units have the same TI sound chip? Am I
>having a wet dream thinking it wouldn't be too hard to run CP/M on this?
I don't think so, I think they merely used a free I/O port to toggle on and
off a line connected to the speaker.
>
>Any one has any appropriate technical documents for the MTX?
>
>-Petteri "piling up the old antique until my home is saturated" Jantti
Steve
andy....@googlemail.com
This thread describes a significantly modded MTX/FDX combo, which I'm sure they be interested in hearing about.
Regarding sound: The MTX has 3 tone channels + 1 noise channel.
The FDX doesn't change this, but the 80 column card in the FDX also supports a single tone beep.
Things have moved on in the Memotech world, we now have
Almost all tapes sampled to .mtx files.
New games ported from other 8 bit micros.
Some MTX games ported to other 8 bit micros.
An emulator that runs on Linux, Windows and MacOSX.
A hardware reconstruction, written in VHDL, running on FPGA.
An add-on for an MTX to add SD Card, RAM Disc and virtual tape support.
Various websites documenting the hardware, software, products, history, etc..
So there are many easy ways to run CP/M on real or virtualised MTX kit.
{{{ Andy