spence@utcsstat.UUCP (10/27/86)
I'd appreciate hearing from anyone who has used CPYAT2PC (or any similar
program). I use an AT as well as several PCs. The AT has a 1.2 Mb drive
in addition to its hard disk. I don't want to add a 360K drive, but I do
want to be able to write 360K diskettes as well as read them.
Does CPYAT2PC really do the job? Are there other solutions?
Ian Spence {allegra,decvax,ihnp4,seismo,watmath}!utcs!utcsstat!spencetla@kaiser.UUCP (T Anderson) (10/28/86)
I've had good luck writing 360K disks on several varieties of 96TPI drives including 1.2 Mb drives on an AT, 800K drives on an Eagle 1620 and others. The normal difficulty seems to be that the write heads on the 96TPI drives is only half as wide and so when used in the 360K mode only reads and writes half the track used by the normal 360K drives. This means that reading is never a problem, but when you write it only changes the information on half of the track. If read back on a 96TPI drive there is no problem (since it only reads the half anyway), but when read on a normal 360K drive the wider head sees conflicting data on the two halves of the track and concludes that the disk is not formatted. There seems to be no way to write both halves of the track with the narrow heads and keep them aligned accurately enough to read back correctly on 360K disk UNLESS the other half is BLANK. The solution I've used without a failure is to use virgin disks (ones never formatted). Format them on the 1.2M drive requesting the 360k density. This means that the other half of each track is not even formatted (random magnetic patterns). Then write whatever is desired on the disk. It may now be read on a 360K drive. BUT NEVER WRITE TO IT USING A 360 K DRIVE. If you ever write to it the other half track will get used and the 1.2M drive will never be able to change that half. The totally unformatted half has such a weak magnetic signal that it causes no problem. Thus you need different disks to copy back and forth, esp in the 1.2M to 360K direction. You have to keep a special disk never written to by a 360K drive just to use for transferring. This is a small nuisance but seems to work everytime. I have considered trying to use disks that have been demagnetized by a bulk tape demagnetizer to see if they work but have never done it. -- Terry L Anderson AT&T Bell Laboratories - Liberty Corners ...!ihnp4!daimler!kaiser!tla
timothym@tekigm2.UUCP (10/28/86)
In article <1986Oct26.184138.24015@utcsstat.uucp> spence@utcsstat.UUCP writes: > >I'd appreciate hearing from anyone who has used CPYAT2PC (or any similar >program). I use an AT as well as several PCs. The AT has a 1.2 Mb drive >in addition to its hard disk. I don't want to add a 360K drive, but I do >want to be able to write 360K diskettes as well as read them. > >Does CPYAT2PC really do the job? Are there other solutions? > >Ian Spence {allegra,decvax,ihnp4,seismo,watmath}!utcs!utcsstat!spence Hi, To quote the IBM PC-DOS Manual for version 3.10, concerning FORMAT.COM: /4 to format a double sided diskette in a high capcity drive. pg. 7-107 Which means that by entering the command 'FORMAT A: /4<cr>' you may format a 360K diskette in a 1.2M disk drive. The manual does mention that this technique is not 100% reliable, and that some 360K disk drives may not be able to read the diskettes formatted in this fashion. I guess it has to do with drive calibration, as I have not had any problems taking diskettes formatted in my AT to my Deskpro at home, or to any other IBM PC. Good Luck all.... -- Tim Margeson (206)253-5240 PO Box 3500 d/s C1-937 @@ 'Who said that?' Vancouver, WA. 98668 {allegra..inhp4..decvax..ucbvax}!tektronix!tekigm2!timothym
coulter@hplabsc.UUCP (Michael Coulter) (10/28/86)
You don't need a special program. A floppy formated as 360K will be written in that format. You can also format a floppy as 360K with the /4 switch. I have read that some PC's may have trouble reading the data, but I haven't encountered any probelms. -- Michael Coulter ...ucbvax!hplabs!coulter