Richard (and Robert and Tony) are right. There are two specific weirdities to the Kaypro format. 1) Kaypro uses a Western Digital disk controller v NEC 765 (or 8272) in PC. Since Kaypro has ten 512 byte sectors per track, things are a little crowded. The WD can start recording sonner after the index than the NEC, and in the Kaypro format, they do. Sometimes the NEC based machines can not read the first sector on a track. The work-around is to either do your own formatting, with a longer gap before the first sector than Kaypro uses, or to ignore the index pulse. Ignoring the index pulse can be done temporarily by putting a piece of opaque tape over the index hole of the jacket of the disk (a write protect tab works great, but PLEASE make sure that it is on solidly and doesn't fall off in the drive!), or for more frequent usage, add a switch in the drive or in the cable to interrupt that signal. 2) The other weirdity (in DS Kaypro formats) is the head number fields in the sector headers. One of the fields in the sector header contains the side number of the disk. With the WD controller, you specify which head you want to read or write with, and can ignore the value in the sector header head number field. With the NEC controller, you specify which head you want to read or write with, and MUST specify what value is expected in the sector header head number field. Kaypro, since they didn't care about what value was in that field, put the wrong value in on the second side of the diskette (only relevant on DS Kaypro formats). Therefore, it is POSSIBLE to read and write Kaypro sectors on the second side with a PC, but NOT using INT13 (unless you replace your INT13 with a somewhat different one). Since it is IGNORING that field, the Kaypro does not mind if you use diskettes that have the correct value in the field. The workarounds: A) Use disks with the correct value in the field by NOT using the Kaypro FORMAT program. a. Modify the Kaypro format program (or write a new one) to put a 1 (the correct value) in the field on the second side of disks. b. Use other software, such as XenoCopy-PC on the PC, to format the Kaypro diskette. B) When reading or writing Kaypro diskettes on a PC, bypass INT13, and talk directly to the hardware. Tell the hardware to look for a 0 in the side 1 head number fields. XenoCopy-PC uses workaround #A. Early versions of Uniform used workaround #B, later versions stopped due to too many PC disk controllers that wouldn't work with it. -- Fred Cisin cisin(a)xenosoft.com XenoSoft http://www.xenosoft.com PO Box 1236 (510) 558-9366 Berkeley, CA 94701-1236 On Wed, 4 Apr 2001, Richard Erlacher wrote: