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Super-Slasher
August 10th, 2003, 05:50 PM
Ugh, now I got a new problem...

After successfully getting a 1.44MB drive to work on my AT, I was attempting to install Windows 3.1 which required extended memory. While reaching for my extended memory card, I was horrified to discover while the night before, one of my friends needlessly reset all the switches on the switchblock to OFF... and I don't remember what they were all set to. My system will not post with the card installed.

Can anyone help me with these switch settings? The card is an IBM "DET 55X3544", has serial and parallel ports (which strangely enough never worked), and 12 30-pin SIMM slots (6 low byte, 6 high byte). The switch block has 8 switches.
Super-Slasher
August 11th, 2003, 05:26 PM
Please? Anyone? I really need this card working again. What exactly is a switchblock for on older cards? For memory address'? I really need help here.
Erik
August 11th, 2003, 06:32 PM
The switchblock is probably the starting memory address for the card.

It depends on what is on the card in total as to what the switches might represent. If I were to guess (and this is only a guess) there would be 4 switches dedicated to determining which 64K block the card addressed at. The rest would probably turn on or off some of the other functionality (such as ports, etc.)

Of course, that's only a guess. You really need someone with the manual for this particliar card (or a very close relative of it) to tell you exactly what the switches do.

Failing that, you might be able to "reverse engineer" the card if you can see all the traces from the ISA bus to the switchblock. Unfortunately, it's probably a multi-layer board. . .

Good luck!

Erik
Terry Yager
August 13th, 2003, 12:00 PM
SuperSlasher:

The worst case is you might have to work it out by trial and error. Remember there are only 256 different combinations of 8 switches. Start from 00000000 and work your way to 11111111. This shouldn't take much more than a day or so.

--T
Super-Slasher
August 17th, 2003, 09:12 AM
Took your advice Terry and got it on attempt #13. Thanks. I would have never thought I could have gotten it with any luck at all. :)
Terry Yager
August 17th, 2003, 03:51 PM
Who said 13 was not a lucky number? Glad you got it so easily. BTW, did you manage to enable the serial and parallel ports? Prolly a couple of those switches will do that fr ya...

--T

(WhooHoo! I finally managed to break 100 posts on this board!)
Super-Slasher
August 17th, 2003, 05:10 PM
Who said 13 was not a lucky number? Glad you got it so easily. BTW, did you manage to enable the serial and parallel ports? Prolly a couple of those switches will do that fr ya...

--T

(WhooHoo! I finally managed to break 100 posts on this board!)

No, net yet, the ports on the card still seem to be inactive. I'll try remedying that later on - got a seperate serial/parallel board I can use in the meantime.