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Olivetti M203 motherboard (from M290-S computer) will not load anything

Glen M

Experienced Member
Joined
Apr 27, 2020
Messages
57
Location
Belfast, Northern Ireland
I managed to get this old board powered up but for the life of me I cannot get it to boot a floppy.

This board was given to me in unknown condition. After hacking up an ATX power supply I got the board to post but when I connect a floppy drive it won't read anything. The drive is detected and you get the normal seek. After the bios checks the drive lights up, tries to read, but then fails with "non-system disk or disk error replace disk and strike and key". The drive and disk are both fine, both verified working on other systems. I have also tried other drives, disks and cables all with the same result.

Someone suggest to me that you need the riser card fitted to the board or it will not work. I don't have the riser but I didn't think this would matter as its just an extension of the ISA bus, surely leaving it off is no different than having empty ISA slots and shouldn't effect the operation of the machine.

There are 2nr 34pin headers on the board. The drive is only detected when connected to the top header and only when using a straight through cable. Using a twisted cable I still get the seek but the drive isn't detected in the bios.

Any idea whats going on here, why this board won't boot from floppy?

Also what is the second 34 pin header for?

Picture of the board for reference, note the battery has since been replaced.

https://i.imgur.com/ljTLxPi.jpg
 
Try putting two drives on the same cable. A: and B:
 
I'll try 2 drives on the one cable but I don't see how that could effect it, worth a shot though.

As for the pocket guide, I've looked through all of it and don't see my board on there. It seems to be pretty much undocumented online.

It was also suggested to me to try chenging the drive to DS0. As DS0 the drive isn't detected on a straight through cable but on a twisted cable it sees 2 drives. The one drive connected does the seek test twice.

I'm starting to lean towards a hardware failure, possibly the floppy controller but could be anything. Next thing I want to try is to take the 40mb hdd out of my olivetti 386 and see if this board will try and boot it.
 
It should be early systems,

cap22.pdf:M290-30 BA 278

or

cap32.pdf:M290-25 BA-08

Not sure, I have such a M290S but not tested/opened yet.
 
I don't know a lot about the M290S. It's a 286 PC from 1989 that was released either in late '89 or early 1990, 1990 seems more likely. It was the first PC to use the BU chassis.

The second header is another disk drive header, used for a two-drive configuration. I don't know which one is for the first drive, maybe the one closest to the chipset? Or maybe it doesn't matter? I think the cables Olivetti supplied with the system were simple one end, no twists cables.

Make sure you configure the BIOS properly. From memory, you use the function keys to select the setting you want to change, space to select the parameter, enter to confirm it and enter again to save the BIOS settings and exit. Do not exit the settings by pressing the escape key as that will not save anything.

I have fragments from an M290S document. I doubt it could be of use to anyone, but if you want it anyway here it is: http://www.filedropper.com/j1
 
Last edited:
Well I figured it out in the end. It wasn't anything to do with settings after all but rather cracked solder joints on the motherboard.

Must have taken me 5 hours before I noticed the damage on what looks like a factory bodge board. Its installed on pins above the RAM slots with 4 wires running off to various points around the board. It was the joints at the pins that had cracked. Repaired that and it booted no problem.

The PDF document is fantastic. It will certainly come in handy, thank you.
 
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