adf@crosfield.co.uk (alex france) (05/17/91)
Absolute Disk Writes to Floppies ================================ We have a real curious problem here, and I wonder if anyone can help? Basically I have a program (Zortech C and DOS 3.3) which writes to absolute disk sectors on a floppy disk. It writes to logical sectors 1 and 30 on High Density floppies, which equate to second sector on first side first track, and last sector on side 2 track 1. The program also sets the floppy type using BIOS call 0x17 (i.e. type 3) before doing the writes. It also reads back the sectors and compares them to ensure that the data made it down onto the disk OK. Now, on our Dell 325 (386/Cached/Phoenix BIOS) this works just fine and produces lots of disks - the disks are actually used as key protection devices on UNIX machines. But, on this Intel SYP-302 box (386/cached/Phoenix BIOS) that our manufacturing guys insist on using, just now and again to keep us guessing and confused, it will write the data for sector 30 on sector 93. It also then reads it also then reads it back from that sector, so my read confirmation test works fine! The disk writes are done using Zortech's dos_abs_disk_write() function, which is really just a C interface on top of the absolute disk write BIOS interrupt. Anyone ever come across anything like this? Both machines appear to use the same V1.10 Phoenix 80386 ROM BIOS PLUS and there appears to be no pattern as to when it chooses to do this. The disks we use are always freshly formatted before we do this. Dazed and Confused, Alex France, Crosfield Electronics, | Phone: +44 442 230000 xt.3541 Hemel Hempstead, HP2 7RH, England. | Fax: +44 442 232301 adf@crosfield.co.uk or mcsun!cel!adf@uunet.uu.net