First post, by waterbeesje
- Rank
- Oldbie
I've got this Multitech MPF-PC 552 for about 4 years now, but never got it to work as expected.
It's an IBM PC clone. It came with original Multitech keyboard and Multitech monochrome CGA screen (composite).
I think it's something special, because I have only seen exactly one more.
Specs:
D8088 processor,
256kB RAM,
FDD controller onboard
5.25 "FDD (tested in different 8088 system, working),
CGA graphics card,
DTC 5150BX 2 MFM controller
MFM hard disk (Shugart 712, 10MB).
Original keyboard
Monochrome monitor (Composite connection for image, with such a lovely high pitch).
This computer came in as not working, plug-in cards and FDD cable were loose and the MFM cables (control and data) were missing.
(mfm controller left out here)
I have put everything together and the computer:
- gives a picture, ram is tested (motherboard, CGA card and monitor therefore work)
- the FDD is being initialized (and tested on my Philips XT computer: works fine)
- the HDD is marked as present by the controller (and tested on my Philips XT computer: works fine)
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Question and story one: the boot floppy.
With the HDD disconnected / controller removed and a floppy disk in the diskdrive (both PC-DOS 3.3 and PC-DOS 5.02 tried) it reads the floppy, and says 'DIOS.COM NOT FOUND' It seem to need this to boot, because the system hangs.
At this pont hitting a random key makes the computer retry to read the floppy disk and returns the same error.
The boot floppys work perfectly with my Philips.
I tried:
1. With my Philips XT I made a fresh boot floppy with PC-DOS 3.30 (using the Multitech FDD to eliminate drive incompatibility). Then I put some standard external commands on the floppy (debug, format etc) and tried to boot the Multitech. No success.
2. Next I copied the IBMBIO.COM as DIOS.COM (just some trial and error, assuming this wouldn't work but who knows) The Multitech turns on, and without the HDD I get the message "DISK BIOS LOADING", followed by the message that it is the wrong version (duh ...) and I have to press [ctrl] [alt] [del] to reboot and get the same error ofc. Conclusion: the floppy drive and floppy both work. DIOS.COM not yet.
3. dug up a bunch of DOS boot disk images on WinWorldPC and checked them for a DIOS file: zero success.
4. dug even deeper on Google, Bing, Yahoo and DuckDuckGo. DIOS.COM seems untraceable: (the only clues are a thread on VCFED.COM and vintagesbc.it where someone also ran into this.
5. Downloaded a CP/M 86 image and it will acyually boot until it hits i/o port errors when trying to initialize them... and hangs.
Now I know that there are people here who also have a lot of old/odd/irregular computers. So my question: Does anyone have this DIOS.COM for the Multitech MPF-PC? I only need this file, however a DOS disk image would be convenient.
Could it be that I need a revised BIOS for this computer? (the chip is a M5L2764k labeled "Multitech BROM 1.1" so perfectly replacable)
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Question and story two: the keyboard.
The hard disk came with this computer and I hooked it up to see if it did something: it only was reported presend by the controller, but did not boot.
As part of my search for a solution, I hooked drive and controller up to my Philips XT and again: hard disk presend, no boot. From boot floppy the drive was not recognized and not readable.
Any AT computer or higher wouldn't help me at all, the ROM was not initialised.
Back to the Philps: I hooked up fdd and hdd (with the controller) from my Multitech and booted from PC Dos 5.02 and after low level + high level format the hard disk did actually boot and seems to have very little bad sectors.
Put FDD/HDD/controller back to the Multitech and it boots from HDD immediately!
And the the keyboard does no longer respond.
Put the boot floppy in (see problem above) and rebooted: any key stroke retries to load DIOS and fails again. Keyboard must be working...
Do I need to preparate some settings / driver to be able to use the keyboard?
side note 1: I really want PC-DOS 5.02 because it's able to use Interlnk / Intersvr and the Scandisk from the Win98 boot disk)
side note 2: Due to this keyboard error I have put PARK.COM into Autoexec.bat, which I can exit by pressing a key. Safe to turn off the computer, and the best test to see if the keyboard does *anything at all* after booting
side note 3: the Multitech keyboard is a standard XT type and works flawless on my Philips. The Philips XT keyboard works fine but also refuses when connected to my Multitech.
Side note 4: I can toggle the caps lock: the LED on the keyboard switches on and off.
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Found a quite similar board in this thread:
Need help identifying 8088 motherboard
For a bit more information about this computer (in Italian, use your favourite translatorwhen convenient):
http://www.vintagesbc.it/?page_id=151
For a little discussion on VCFED:
http://www.vcfed.org/forum/showthread.php?261 … -8088-need-help
(last post is mine 😀 )
Stuck at 10MHz...