Path: utzoo!utgpu!watmath!uunet!xanth!nic.MR.NET!hal!cwjcc!gatech!ukma!husc6!spdcc!gnosys!gst From: gst@gnosys.UUCP (Gary S. Trujillo) Newsgroups: unix-pc.general Subject: Re: Odds and Ends (Questions on 3B1) Summary: Use "md-format -9" to format 9-sector floppies Keywords: MS-DOS floppy format Message-ID: <95@gnosys.UUCP> Date: 26 Dec 88 20:58:08 GMT References: <1078@naucse.UUCP> Reply-To: gst@gnosys.UUCP (Gary S. Trujillo) Organization: gst's 3B1 - Somerville, Massachusetts Lines: 55 In article <1078@naucse.UUCP> sbw@naucse.UUCP (Steve Wampler) writes: >I have a few questions that have been puzzling me. Nothing >earth shattering, but I'm curious... > >(2) Has anyone tried to rewrite the ms-dos formatter to format > at 9 sectors instead of 8?... Well, it's been several months, and some folks may have missed the answer from Roger Abrahams that I received in response to my having asked that same question, so I'll quote him again on the subject: |From tailorme!marque.uucp!roger |To: gst@gnosys.uucp |Subject: Re: Minor fix to Mtools patch for 3.5" disks |Newsgroups: unix-pc.bugs,comp.sys.att,unix-pc.general |In-Reply-To: <56@gnosys.UUCP> |References: <611@bacchus.UUCP> |Organization: Marquette University, Milwaukee, WI |Message-Id: <8808212331.AA09610@marque.mu.edu> |Date: 21 Aug 88 23:31:02 CDT (Sun) |From: Roger Abrahams | |In article <56@gnosys.UUCP> you (I) write: |>In article <611@bacchus.UUCP> darren@bacchus.UUCP (Darren Friedlein) writes: |>>... |>>One thing I'd like to find is a program like MsdosF.sh that will format |>>3.5" disks. Anyone know how to do this? |> |>For that matter, does anyone know how to format 5.25" floppies at 360K? |>Far as I know, /usr/bin/MsdosF.sh will only format 320K (8-sector) disks. | |Wrongo! If you have "strings", you can see that the program that does the |actual format (md_format) has the following options: -1289bv | |If you say "md-format -9" you will get a 360k disk. Actually unix can't make |a 9 sector disk (odd sectors are reserved for bad block mapping on a hard |disk, and this is also how it tells a hard from a floppy disk), so it |actually makes up a 10 sector format, but only allocates 9 sectors. | |I leave the rest of the options to you, to figure out yourself... | | - Roger I hope this answer helps you as much as it did me. The only problem is that I have found that I sometimes have problems reading floppies thus formatted when I try to read them on a MS-DOS machine. It may have to do with the El Cheapo diskettes I tend to use, or an alignment mismatch, or other factors, but the additional density necessary to write 10 sectors may also have some- thing to do with the problem. Far as I know, the UNIXpc cannot format disks with an odd number of sectors, though it can read them OK. Roger explained the situation to me, but I've forgotten the details. -- Gary S. Trujillo {linus,bbn,m2c}!spdcc!gnosys!gst Somerville, Massachusetts {icus,ima,stech,wjh12}!gnosys!gst