liber@darth.UUCP (Eric Liber) (11/16/88)
To the poster who asked about windows on a compaq (sorry about subject line) and trashing his screen when writing to floppy disks. I mentioned a problem that i had with the award bios on my gateway 386 which would hang the computer if you accessed the hard drives. I traced that problem to a bios bug which does not disable interrupts at the correct time when writing or reading from the floppies. I had exactly the same problem in a hard disk device driver I wrote for another system (custom hardware) a couple of years ago where any interrupt activity while reading from the HD would instantly crash the system. While i do not know for sure about the COMPAQ bios i know personally of one other site that is using a COMPAQ 386 machine for a file server on a network that will crash if you try to read the floppy drive when the server is running.... sound familiar? I would suspect the bios first but it could be an interrupt conflict between the video card and the floppy controller also. Call COMPAQ and bitch , bitch , bitch until they do something. Realistically I have found that you have to persue these things until you find just the right person at the vendor who "knows" about the problem and/or is willing to help. Once you find that person usually you can solve your problem. Another possible method would be to buy, borrow, beg or steal :-) a periscope or atron debugging card and software and trace thru the bios to find the confilct. I have used the periscope system and it can be a big help in finding these types of bugs. Using the periscope card with the hardware break point and buss cycle trace facility you could simply set a break when ever the buss address was in the video memory then execute a small program that continually hit the floppy. When the screen gets trashed the periscope card would execute a break and with any luck you will be looking at the memory location that caused the glitch. If it is in the BIOS then you can really yell at COMPAQ. GOOD LUCK Eric