jef@djinn.bellcore.com (Jonathan E. Flamm) (06/28/88)
I know that there are problems with diskettes written on 1.2MB drives when they are read on 360KB drives ( I believe it has to do with only 1/2 of the track being written due to the narrow track width). Is there software available that will RELIABLY write 360K diskettes on 1.2MB drives so they can be reliable read on 360K drives. I know that there is no problem with the new 3 1/2 1.44MB and 720K formats. Jonathan Flamm jef@flash (arpa) bellcore!jef (uucp)
jamesd@percival.UUCP (James Deibele) (06/30/88)
In article <8362@bellcore.bellcore.com> jef@djinn.UUCP (Jonathan E. Flamm) writes: >I know that there are problems with diskettes written on 1.2MB drives >when they are read on 360KB drives ( I believe it has to do with only >1/2 of the track being written due to the narrow track width). Is there >software available that will RELIABLY write 360K diskettes on 1.2MB drives >so they can be reliable read on 360K drives. >I know that there is no problem with the new 3 1/2 1.44MB and 720K formats. > Hmmm. I was just reading Steve Gibson's column in (MIS)InfoWorld (that used to be the popular derogatory name for it, back when it covered systems outside the Macintosh-IBM axis; now that every article is for the Management Information Systems types (you know, the ones with the polyester shirts and rayon ties who don't buy dozens of C and UNIX books) it seems sadly appropriate.) that he has to use a 360K, 1.2MB, 720K, and 1.44MB to get reliable reads and writes. I don't know about the 3 1/2 drives, but I've had very good luck with a TEAC 1.2MB drive writing (and even diskcopying) diskettes that were formatted on a 360K drive. I've read that you should always format on a 360K first if possible, and personal experience has shown this to be a good idea. They're the only brand that I know for sure will work, but there may be others. -- James S. Deibele jamesd@qiclab or jamesd@percival TECHbooks: The Computer Book Specialists (800) TECH-BKS 3646 SE Division Portland, OR 97202 (503) 238-1005 TECHbooks One BBS (#1:105/4.0); 3/12/24 (503) 760-1473
stevewa@upvax.UUCP (Steve Ward) (07/04/88)
I too have had good luck with 1.2M TEAC drives writing 360K floppies. I have such a beast on my AT at home, and had to recently install an upgraded software package on a client's XT. I was concerned the floppies wouldn't read, but the Epson drive in his Wyse PC read my disk just fine. If you buy a copy of the COPYiiPC program, it includes a utility called BULKERAS. This is a program that will completely blank out a disk. It works with 1.2M drives as well...it's good insurance before you format your 360K disks. Steve stevewa@upvax.UUCP !tektronix!upvax!stevewa
ray@micomvax.UUCP (Ray Dunn) (07/07/88)
In article <8362@bellcore.bellcore.com> jef@djinn.UUCP (Jonathan E. Flamm) writes: >I know that there are problems with diskettes written on 1.2MB drives >when they are read on 360KB drives ( I believe it has to do with only >1/2 of the track being written due to the narrow track width). Is there >software available that will RELIABLY write 360K diskettes on 1.2MB drives >so they can be reliable read on 360K drives. There is no *RELIABLE* way of doing this. The problem is not with software it is with physics. There have been several replies saying: "Brand X seems to work fine", "I have had good luck with...". Please note that this is *INDEED* a question of luck, and a factor of *both* the 1.2 Meg drive you are writing on, *and* the 360K drive you are reading from, *and* the quality of the media you are using. There is probably a higher correlation between particular *samples* of drives than between particular manufacturers of drives. It is indeed true that you increase your chances of success if you format the disks on a 360K drive. >I know that there is no problem with the new 3 1/2 1.44MB and 720K formats. Unfortunately, this is not totally correct, the problems are just a little more devious! The early IBM PS/2 machines showed serious interchangeability problems, and many clone PC's with 3.5 inch drives still do. Lack of a full specification standard for 1.4Meg drives is part of the problem, and again, physics comes into play! In particular, look for the following problem: Diskettes formatted on a 720K drive and overwritten on a 1.44 Meg drive (at 720K density) are often then unreadable on a 720K drive. The severity of the problem varies very distinctly from drive manufacturer to manufacturer, and from sample to sample. It appears to be rare on *current* IBM PS/2 machines. There are significant interchangeability problems from manufacturer to manufacturer with 1.4Meg diskettes. Don't rely on being able to carry a 1.4Meg diskette from your machine to one of a different make! The fact that early 3.5 inch drives (and some current ones) did not check the media has caused some grief. This allows a diskette to be formatted at the wrong density, i.e. allows a 720K diskette to be formatted as 1.4Meg, or, just as bad, 1.4Meg as 720K. Unfortunately, I am not at liberty to identify the worst offenders in the interchangeability game!! The above is fact, the following is opinion. I don't have the info at my fingertips, but I believe some IBM PS/2 machines may still not lock out illogical format attempts correctly. As clone manufacturers, we have spent much time and effort identifying and overcoming these problems. Disclaimer: The above should be taken as personal opinion of the writer, may not reflect that of Philips Electronics Ltd., and is given for information purposes only. -- Ray Dunn. | UUCP: ..!{philabs, mnetor}!micomvax!ray Philips Electronics Ltd. | TEL : (514) 744-8200 Ext: 2347 600 Dr Frederik Philips Blvd | FAX : (514) 744-6455 St Laurent. Quebec. H4M 2S9 | TLX : 05-824090
cjl@ecsvax.uncecs.edu (Charles Lord) (07/08/88)
I don't think it is luck that makes my AT clones work. I have seen the incompatability nightmare on other's IBM PC/AT's, but when I bought 4 Wells-American A*Star clones with the TEAC drives, I started testing all combinations of read/write of 360K and 1.2M disks. I have had ZERO no-reads of disks either way with about 10-12 assorted PCs and PC compatables in and out of our company with an estimated 200-300 disks. These disks have been formatted on both a 360k PC and the AT clones with no discernable differences. I have even re-formatted 360Ks on the A*Star that were originally formatted on a PC then wrote files and sent the disk to a PC (presumably the ultimate sin) with no problems. Perhaps I have had a silver cloud over my head these last 2-1/2 years, but quite frankly I doubt it, with the sorry luck we have had with OTHER stuff (accessory cards and UPSs, etc). -- Charles Lord cjl@ecsvax.UUCP Usenet Cary, NC cjl@ecsvax.BITNET Bitnet #include <std.disclamers> #include <cutsey.quote>