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Magitronic PC/XT FDC I/O Card Not Working

kc8eyt

Experienced Member
Joined
Aug 7, 2020
Messages
323
Hello. Last year I picked up a brand new Magitronic PC/XT system on eBay. About a month ago I finally got around to tinkering with it.

The original full length FDC, dual COM, LPT, Game, and RTC card has extensive Varta battery damage but still works. It's this card:

https://stason.org/TULARC/pc/io-cards/P-R/PC-CRAFT-INC-Multi-I-O-card-DISK-I-O-CARD.html

I'll need to replace and repair many of the components on the card. In the mean time I picked up this I/O card on eBay:

https://www.ebay.com/itm/NEW-8-Bit-...-XT-PC/233934700478?ssPageName=STRK:MEBIDX:IT

My question: Does anyone have the correct documentation for this card? The seller's pictures of documentation are incorrect. The only markings on the card that help in identification are JCC and IOS-2. The card appears to be a variant of these two cards I found:

https://stason.org/TULARC/pc/io-cards/M-O/ORBITON-CORPORATION-Multi-I-O-card-ORBIT-XT-I-O-PE.html
https://stason.org/TULARC/pc/io-cards/I-L/JUKO-LABORATORIES-LTD-Multi-I-O-M16-X.html

If you would like to read further here is the problem(s) I am facing:

This is the motherboard (sorry could only find a pdf):

http://www.minuszerodegrees.net/manuals/TurboXT - motherboard.pdf

I removed the original Magitronic MGA/parallel video card and installed an 8bit Oak VGA card:

https://stason.org/TULARC/pc/graphics-cards/M-O/OAK-TECHNOLOGIES-INC-VGA-OAK-VGA-8-BIT-VERSION.html

I removed the original ST412 MFM controller and 10MB ST412 full height HDD and installed a lo-tech XTIDE attached to a CF card reader:

https://www.ebay.com/itm/Lo-tech-XT...Tested/284233499409?ssPageName=STRK:MEBIDX:IT
https://www.amazon.com/gp/product/B000T9QQP0?psc=1

I installed an 8bit Media Vision Thunderboard:

https://stason.org/TULARC/pc/sound-...ON-TECHNOLOGY-INC-Sound-card-THUNDERBOAR.html

Everything works just fine with this setup and the original FDC I/O controller installed. When I replaced the I/O controller with the one I purchased on eBay the CF card failed to boot, "Missing Operating System". I pulled the Lo-Tech XTIDE card and then the new FDC card came up with a menu asking to identify the drives attached. I set the card up for two 360KB 5¼" drives. Putting the Lo-Tech back in yields the same results as before, "Missing Operating System"

Pulling the lo-tech XTIDE back out I realized the new I/O card will not boot from floppy either. The A: drive clicks a few times and then "Non system disk or disk error, replace and press enter to try again". I tried playing the binary shuffle with the jumpers on the I/O card but more often than not was greeted with 601 errors on system startup.

The seller is sending me another card to eliminate the possibility of a bad card. Any ideas/suggestions at this point would be greatly appreciated.
 
Last edited:

SomeGuy

Veteran Member
Joined
Jan 2, 2013
Messages
4,203
Location
Marietta, GA
Well, first thing, it sounds like there is an address conflict between the BIOS on this Magitronic card and your XTIDE. You will have to change the base address on one or the other. Just going by the specs of the similar cards, it looks like there are actually jumpers for that.

Now, the issue with not reading the floppy could be more complicated. I've never trusted a high density 8-bit controller that does not have jumpers/switches for selecting drive types. Where the blazes does it store that information?

This card's BIOS actually prompted you to select drive type? Does it continue to report the same drive types you selected? If not, perhaps it is storing it using something equivalent to CMOS since it seems to have a built in clock - in which case it might need a good battery to work.

Although unlikely, I wonder if perhaps this actually requires an AT? It shouldn't since it has it's own BIOS. Still, one way to check for that kind of BIOS issue is to try booting DR-DOS 5 or 6. DR-DOS has some clever way of working around BIOS, so it may work when PC/MS DOS won't.

Of course, the FDC chip could be dead. I've seen those UM chips fail before.

BTW, dumping the BIOS rom might give some idea of how this card works.
 

kc8eyt

Experienced Member
Joined
Aug 7, 2020
Messages
323
Well, first thing, it sounds like there is an address conflict between the BIOS on this Magitronic card and your XTIDE. You will have to change the base address on one or the other. Just going by the specs of the similar cards, it looks like there are actually jumpers for that.

Yep, my first thought as well. My first hurdle though is to get the FDC controller booting from a floppy on it's own without the XTIDE installed. Both of the similar jumper settings to this card I found reference a JP10 jumper block, which this card does not have.

Now, the issue with not reading the floppy could be more complicated. I've never trusted a high density 8-bit controller that does not have jumpers/switches for selecting drive types. Where the blazes does it store that information?

This card's BIOS actually prompted you to select drive type? Does it continue to report the same drive types you selected? If not, perhaps it is storing it using something equivalent to CMOS since it seems to have a built in clock - in which case it might need a good battery to work.

Yes, the card came up with a prompt asking for the drive types. I placed a new CR2016 battery into the card before installing it for the first time. After each subsequent boot the card reports the drive types on screen as the ones I chose. There is also an option to press ESC to change the options.

Although unlikely, I wonder if perhaps this actually requires an AT? It shouldn't since it has it's own BIOS. Still, one way to check for that kind of BIOS issue is to try booting DR-DOS 5 or 6. DR-DOS has some clever way of working around BIOS, so it may work when PC/MS DOS won't.

I installed the card into a 386DX/40 and it did the same thing. However, this time I was unable to press ESC at any point to change the drive types. It didn't matter if I set the 386's BIOS to the actual drive types, or nothing, same result.

Of course, the FDC chip could be dead. I've seen those UM chips fail before.

I'm hoping it's a defective card. There is another one coming in the mail.

BTW, dumping the BIOS rom might give some idea of how this card works.

If the second card I receive has the same symptoms then investigating further will be needed I agree.

Thank you for the reply :)
 
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