lenny@icus.islp.ny.us (Lenny Tropiano) (04/30/89)
Yes, Gil and I have done it again ... another ribbon cable coming out
of our machines. (That's four cables for me, two 34 pin cables, one
20 pin cable, and a 36 pin cable for my parallel printer). It's getting
a little crowded back there :-)
After coming back from the Trenton Computer Festival last weekend, both
with 720K 3.5" floppy disk drives (for $30 a piece), we decided to install
them in our UNIX pc's. The drives are Sony Model MP-F63W-01D, 3.5" 720K
floppy units. We bought them, the cases, the ribbon cable, the switch,
edge connectors and the DIL connector all for about $60/each...
The only "snag" we had was that the drive didn't assert the FDREADY* signal
on pin 34. This caused the system to think there was no disk inserted, or
the door was open, even though neither were true. Gil whipped up a little
fix for that one and he grounded the FDREADY* signal only when the drive
was selected.
Now how did we manage to get both drives on the UNIX pc at once, since the
hardware only supports one ... Well it's sorta a hack, but basically it's
a mechanical switch (SPDT) that switches the FDRIVE0* signal (pin 10) between
the 5.25" drive (360K) and the 3.5" drive (720K). Both cannot be accessed
at the same time, but who cares ... the switch in one direction gets you
original 5.25" drive that is still in the case, the other way is the 720K
drive externally...
It's nice to have all this space on a floppy!
/floppy (/dev/fp021): 1560 blocks 190 i-nodes
total: 1590 blocks 192 i-nodes
(That's 814,080 bytes ... 10 sectors/track, 80 tracks)... 800K!
I was able to put a floppy boot unix, floppy filesystem (all the necessary
patching utilities [fsck, fsdb, etc..]) and the diagnostic program all
on a 3.5" disk with a verbose loader. Ahh, no more switching disks to
boot a Floppy Unix!
If you want more details on the hardware aspects, I suggest you contact
my hardware expert... Gil Kloepfer, Jr. (gil@limbic)
-Lenny
--
Lenny Tropiano ICUS Software Systems [w] +1 (516) 582-5525
lenny@icus.islp.ny.us Telex; 154232428 ICUS [h] +1 (516) 968-8576
{talcott,decuac,boulder,hombre,pacbell,sbcs}!icus!lenny attmail!icus!lenny
ICUS Software Systems -- PO Box 1; Islip Terrace, NY 11752erict@flatline.UUCP (J. Eric Townsend) (05/01/89)
In article <695@icus.islp.ny.us> lenny@icus.islp.ny.us (Lenny Tropiano) writes: >Yes, Gil and I have done it again ... another ribbon cable coming out [...] >If you want more details on the hardware aspects, I suggest you contact >my hardware expert... Gil Kloepfer, Jr. (gil@limbic) Please, please, please post the details, Gil.... -- If you're not using UNIX, you're just using an operating system... J. Eric Townsend Inet: <temporarily disabled> 511 Parker #2 Houston,Tx,77007 EastEnders Mailing List: eastender@flatline.UUCP
cmv@ihlpf.ATT.COM (C M Votava) (05/01/89)
In article <695@icus.islp.ny.us> lenny@icus.islp.ny.us (Lenny Tropiano) writes: >After coming back from the Trenton Computer Festival last weekend, both >with 720K 3.5" floppy disk drives (for $30 a piece), we decided to install >them in our UNIX pc's. > >Now how did we manage to get both drives on the UNIX pc at once, since the >hardware only supports one ... Well it's sorta a hack, but basically it's >a mechanical switch (SPDT) that switches the FDRIVE0* signal (pin 10) between >the 5.25" drive (360K) and the 3.5" drive (720K). I did this "enhancement" to my unixpc very recently too, but solved it in a little different way. First, I simply replaced the existing floppy ribbon cable, with a stock IBM PC floppy ribbon cable (the one with connectors for 2 floppys, without the "twist" in it). Next, I moved the drive select on the 5.25" floppy from drive select 0 to drive select 1, and set the 3.5" floppy drive select to drive select 2. Then, all I had to do is wirewrap in a switch off of the connector on the 3.5" floppy that connects drive select 0 to either drive select 1, or drive select 2 to engage either drive. The next step, is to modify Emmet's MSDOS programs to access the higher density drives. In the source he provides, he includes the init.c routines for both the unixpc, and IBM-PC's so it was a simple matter to copy the appropriate values from one to the other. I now have the "mdir" command working fine off of the 720K disks! However, when I try to use one of the programs that actually go out and try to access the file (like mtype) all I get back is garbage. Obviously, there is a problem in finding the start of the file using the pointer in the FAT, but I haven't had time to figure it out yet. Anybody want to throw me a hint before I dive in all the way? The final step will be to get the DOS-73 code to handle the 720K disks, that will be nice! -Craig Votava [att!]!ihlpf!cmv cmv@ihlpf.ATT.COM
psfales@cbnewsc.ATT.COM (Peter Fales) (05/02/89)
In article <695@icus.islp.ny.us>, lenny@icus.islp.ny.us (Lenny Tropiano) writes: > I was able to put a floppy boot unix, floppy filesystem (all the necessary > patching utilities [fsck, fsdb, etc..]) and the diagnostic program all > on a 3.5" disk with a verbose loader. Ahh, no more switching disks to > boot a Floppy Unix! > > If you want more details on the hardware aspects, I suggest you contact > my hardware expert... Gil Kloepfer, Jr. (gil@limbic) Would you be willing to provide some more details on how to create a bootable floppy file system - either on two disks or on one. A couple of us here (hi Craig) have also put 720K drives on our systems, though I used a 5.25" rather than a 3.5. -- Peter Fales AT&T, Room 5B-414 2000 N. Naperville Rd. UUCP: ...att!ihlpb!psfales Naperville, IL 60566 Domain: psfales@ihlpb.att.com work: (312) 979-8031
kubiak@bach.csg.uiuc.edu (Ken Kubiak) (05/02/89)
In article <8366@ihlpf.ATT.COM> cmv@ihlpf.UUCP (C M Votava) writes: > >The next step, is to modify Emmet's MSDOS programs ... Do I infer correctly that there is a set of unix commands to do dir, type, copy, etc. on MSDOS diskettes? This would be very nice. I'm getting tired of UA's MSDOS un-utilities that won't even let you overwrite a file on the MSDOS disk. Where do I get these utilities from? Thanks in advance, Ken Kubiak Computer Systems Group University of Illinois at Urbana-Champaign kubiak@csg.uiuc.edu
jmc@elvin.ESAM.NWU.EDU (Marc Chandonia) (05/02/89)
I would also like to know where to get the MS-DOS disk utilities (mtools?). Is there a set which is tuned to the UNIX-PC and which will read both low (360K) and high (1.44M) density floppies? Thanks, JMC -- John-Marc Chandonia | jmc@nuacc.acns.nwu.edu Integrated Science Program | jmc@elvin.esam.nwu.edu Northwestern University | jmc@isp.isp.nwu.edu
wouk@smoke.BRL.MIL (Dr. Arthur Wouk ) (05/03/89)
In article <406@elvin.ESAM.NWU.EDU> jmc@elvin.ESAM.NWU.EDU (Marc Chandonia) writes: > > I would also like to know where to get the MS-DOS disk utilities >(mtools?). get mtools1.4 by ftp 128.146.8.62 #cheops.cis.ohio-state.edu pub/archives/att7300 ` ` ` ` ` ` ` ` ` ` for rn ` ` `
gil@limbic.UUCP (Gil Kloepfer Jr.) (05/03/89)
In article <8366@ihlpf.ATT.COM> cmv@ihlpf.UUCP (C M Votava) writes: [who did the 3.5" floppy enhancement to the UNIX-pc] >First, I simply replaced the existing floppy ribbon >cable, with a stock IBM PC floppy ribbon cable (the one with connectors for >2 floppys, without the "twist" in it). Next, I moved the drive select on the >5.25" floppy from drive select 0 to drive select 1, and set the 3.5" floppy >drive select to drive select 2. Then, all I had to do is wirewrap in a switch >off of the connector on the 3.5" floppy that connects drive select 0 to either >drive select 1, or drive select 2 to engage either drive. >-Craig Votava [att!]!ihlpf!cmv Thanks Craig... this is 98% the same as what Lenny and I did. I've been swamped with requests for the details (which I will post, be patient, I'm kind of in the middle of moving!). Actually, I like Craig's method better than the one I used (I cut the ribbon cable rather than using the existing drive select). In any event, those who want a head-start can simply use this method. I'll post the same thing (almost) in more detail in a week or so. ------ | Gil Kloepfer, Jr. | ICUS Software Systems/Bowne Management Systems (depending on where I am) | {decuac,boulder,talcott,sbcs}!icus!limbic!gil or gil@icus.islp.ny.us
tlh@pbhacker.UUCP (Lee Hounshell) (05/04/89)
In article <695@icus.islp.ny.us> lenny@icus.islp.ny.us (Lenny Tropiano) writes: >Now how did we manage to get both drives on the UNIX pc at once, since the >hardware only supports one ... Well it's sorta a hack, but basically it's >a mechanical switch (SPDT) that switches the FDRIVE0* signal (pin 10) between >the 5.25" drive (360K) and the 3.5" drive (720K). Instead of using a mechanical switch, why not change the system's device drivers to make use of the 4th LED as a switch. You would still only be able to access one drive at a time, but you could do it remotely and not have to manually flip a switch. Here's how it might be done.. if the 5 1/4 drive device file is accessed, the disk device driver would turn "off" the fourth LED and (with some minor main-board modifications) this would cause a physical connection to be made with the 5 1/4 drive. If the 3.5 device file is accessed, the exact opposite would occur. comments? Lee Hounshell
alex@wolf.umbc.edu (Alex Crain) (05/05/89)
In article <115@pbhacker.UUCP> tlh@pbhacker.UUCP (PUT YOUR NAME HERE) writes: >Instead of using a mechanical switch, why not change the system's device >drivers to make use of the 4th LED as a switch. You would still only be able >to access one drive at a time, but you could do it remotely and not have to >manually flip a switch. Here's how it might be done.. if the 5 1/4 drive >device file is accessed, the disk device driver would turn "off" the fourth >LED and (with some minor main-board modifications) this would cause a physical >connection to be made with the 5 1/4 drive. If the 3.5 device file is accessed, >the exact opposite would occur. comments? How come nobody thought of this before? This is a *GREAT* idea! Somebody would have to write a quickie driver for the two disks that would use a semaphore to handle bus arbitration on the cable during floppy I/O, and you would probably want to prohibit making either disk a mountable file system (managing that level of bus activity would be pretty fierce), but it would certainly be nice. :alex Alex Crain Systems Programmer alex@umbc3.umbc.edu Univ Md Baltimore County umbc3.umbc.edu!nerwin!alex
lenny@icus.islp.ny.us (Lenny Tropiano) (05/06/89)
In article <115@pbhacker.UUCP> tlh@pbhacker.UUCP (PUT YOUR NAME HERE) writes: |>In article <695@icus.islp.ny.us> lenny@icus.islp.ny.us (Lenny Tropiano) writes: |>>Now how did we manage to get both drives on the UNIX pc at once, since the |>>hardware only supports one ... Well it's sorta a hack, but basically it's |>>a mechanical switch (SPDT) that switches the FDRIVE0* signal (pin 10) between |>>the 5.25" drive (360K) and the 3.5" drive (720K). |> |>Instead of using a mechanical switch, why not change the system's device |>drivers to make use of the 4th LED as a switch. You would still only be able |>to access one drive at a time, but you could do it remotely and not have to |>manually flip a switch. Here's how it might be done.. if the 5 1/4 drive |>device file is accessed, the disk device driver would turn "off" the fourth |>LED and (with some minor main-board modifications) this would cause a physical |>connection to be made with the 5 1/4 drive. If the 3.5 device file is |>accessed, the exact opposite would occur. comments? |> Sounds intriguing, but seems to me to be overkill. Making the changes in the wire (ribbon cable) to change the FDRIVE0* signal (pin 10) was pretty simple. No hacking on the motherboard. The drawback on your method is that it would require you to load a device driver to use the 3.5" floppy drive. This means if you want to use it from the Floppy UNIX, it becomes kinda hard without all the pieces for loading device drivers ... (yeah you could mess around with mounting the hard disk and loading the device, but that's more hassle than it's worth -- it's something I messed around with trying to load the "Cartridge Tape Driver" from the floppy, to restore an entire "/" backup). I'm not shooting your idea down completely. I sorta like the idea of not having to worry which direction the switch is in, when I want to access a floppy, but for the amount of time you actually use the floppy, I'll just do it my way... Thanks for the ideas ... keep 'em rolling in (on all topics)... -Lenny -- Lenny Tropiano ICUS Software Systems [w] +1 (516) 582-5525 lenny@icus.islp.ny.us Telex; 154232428 ICUS [h] +1 (516) 968-8576 {talcott,decuac,boulder,hombre,pacbell,sbcs}!icus!lenny attmail!icus!lenny ICUS Software Systems -- PO Box 1; Islip Terrace, NY 11752
gst@gnosys.UUCP (Gary S. Trujillo) (05/08/89)
In article <10192@smoke.BRL.MIL> wouk@brl.arpa (Dr. Arthur Wouk (ARO-MATH|jerry) <wouk>) writes: | | get mtools1.4 by | | ftp 128.146.8.62 | | #cheops.cis.ohio-state.edu pub/archives/att7300 You can also get them straight from the source (Emmet Gray) via ftp from cerl.cecer.army.mil. There's also the Procomm clone "pcomm" and Emmet's modified version of Steve Grandi's xmodem online. All three were written with the UNIX-pc in mind. -- Gary S. Trujillo {linus,bbn,m2c}!spdcc!gnosys!gst Somerville, Massachusetts {icus,ima,stech,wjh12}!gnosys!gst