5 Mar
2005
5 Mar
'05
9:07 p.m.
Ok, I finally found an 8" drive that worked. I don't think there's a
coincidence that it's half-height, and seems to have been made in the 1982
timeframe. I can't tell who the manufacturer is because I haven't
unbolted it from the chassis it's installed in to check yet.
I was able to format a disk mostly successfully (more on this in a bit)
and transfer MS-DOS 6.22 to it. It was pretty nifty booting DOS on my PC
off an 8" drive ;)
So anyway, when I was formatting the disk, it didn't seem to like the last
4-6 tracks or so. Above the clatter of the noisy fan (bad bearings) I
could hear the head recalibrating. When the format finished, it reported
107520 bytes in bad sectors. This comes out to 210 bad sectors (assuming
512 bytes per sector) which comes out to some weird number of tracks.
Aren't there supposed to be 26 sectors per track?
The main hurdle has been jumped, so I'm in good shape at this point.
Thanks for the tips, all!
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
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5 Mar
5 Mar
9:42 p.m.
New subject: Got 8' drive on PC working
Sellam wrote about 8-inch drives:
Aren't there supposed to be 26 sectors per track?
That would be the standard format for DD (MFM) 256-byte sectors,
or SD (FM) 128-byte sectors. But if you set the PC BIOS to
believe it is a 5.25" HD disk, it should think it's PC 1.2M format,
15 sectors of 512 bytes. It will also think that there are 80
tracks/side, while the drive only supports 77, so it's not surprising
that there were problems on the last tracks.
It never would have occurred to me that you'd try to use MS-DOS
to format 8-inch disks. I thought you were just trying to read
disks.
Anyhow, older versions of MS-DOS allowed you to tell FORMAT
how many tracks to use, though I'm not sure it was actually
willing to accept arbitrary values. And I'm not sure what
DOS 6.22 allows.
Eric
6 Mar
6 Mar
1:55 a.m.
New subject: Got 8' drive on PC working
On Sat, 5 Mar 2005, Eric Smith wrote:
Sellam wrote about 8-inch drives:
Ok, makes sense. So the new calculation is:
107520 / 512 = 210 / 15 = 14. The second time I tried to format a disk
under DOS (to demonstrate to Mr. Johnny Lawson) I heard way more
recalibrations than I did the first time. 14 tracks worth sounds about
right.
Aren't there supposed to be 26 sectors per
track?
That would be the standard format for DD (MFM) 256-byte sectors,
or SD (FM) 128-byte sectors. But if you set the PC BIOS to
believe it is a 5.25" HD disk, it should think it's PC 1.2M format,
15 sectors of 512 bytes. It will also think that there are 80
tracks/side, while the drive only supports 77, so it's not surprising
that there were problems on the last tracks. It never would have occurred to me that you'd try
to use MS-DOS to
format 8-inch disks. I thought you were just trying to read disks.
Well, I needed some way to test whether the setup was working. It
basically is. Now, on to reading those CP/M disks.
It was fun booting my PC into DOS 6.22 off an 8" drive though.
Anyhow, older versions of MS-DOS allowed you to tell
FORMAT
how many tracks to use, though I'm not sure it was actually
willing to accept arbitrary values. And I'm not sure what
DOS 6.22 allows.
I experimented very briefly with this the last time I tried getting this
to work but not enough to come up with anything conclusive. DOS does seem
to expect a certain combination of "sane" values.
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
7 Mar
7 Mar
1:03 a.m.
New subject: Got 8' drive on PC working
On Sat, Mar 05, 2005 at 10:55:19PM -0800, Vintage Computer Festival wrote:
I experimented very briefly with this the last time I tried getting this
to work but not enough to come up with anything conclusive. DOS does seem
to expect a certain combination of "sane" values.
Yes, see my note about using FDFORMAT instead.
--
Jim Leonard http://www.oldskool.org/ Email: trixter at oldskool.org
Like PC games? Help support the MobyGames database: http://www.mobygames.com/
Or taste a slice of the demoscene at http://www.mindcandydvd.com/
5 Mar
5 Mar
9:43 p.m.
From: "Vintage Computer Festival" <vcf at siconic.com>
Sent: Saturday, March 05, 2005 8:07 PM
Ok, I finally found an 8" drive that worked. I
don't think there's a
coincidence that it's half-height, and seems to have been made in the 1982
timeframe. I can't tell who the manufacturer is because I haven't
unbolted it from the chassis it's installed in to check yet.
I was able to format a disk mostly successfully (more on this in a bit)
and transfer MS-DOS 6.22 to it. It was pretty nifty booting DOS on my PC
off an 8" drive ;)
So anyway, when I was formatting the disk, it didn't seem to like the last
4-6 tracks or so. Above the clatter of the noisy fan (bad bearings) I
could hear the head recalibrating. When the format finished, it reported
107520 bytes in bad sectors. This comes out to 210 bad sectors (assuming
512 bytes per sector) which comes out to some weird number of tracks.
Aren't there supposed to be 26 sectors per track?
The main hurdle has been jumped, so I'm in good shape at this point.
Thanks for the tips, all!
--
Sellam Ismail Vintage Computer
Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger
http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage
mputers ]
[ and academia at www.VintageTech.com || at
http://marketplace.vintage.org ]
8" drives have 77 tracks, PC-DOS uses 40 or 80 tracks. Only the 80 track
mode (5.25" HD - 1.2mb) comes close.
Trying to use 80 tracks can destroy your drive.
STOP IT!!!!
You should NEVER use it to boot DOS unless you get Open-DOS and create a
driver for 8".
Randy
www.s100-manuals.com
11:48 p.m.
Randy McLaughlin wrote:
8" drives have 77 tracks, PC-DOS uses 40 or 80
tracks. Only the 80
track mode (5.25" HD - 1.2mb) comes close.
Trying to use 80 tracks can destroy your drive.
STOP IT!!!!
Or, use a program like FDFORMAT to format your disks with /t:77. But yes,
don't use DOS format if it won't take a non-40/80 argument.
6 Mar
6 Mar
1:56 a.m.
On Sat, 5 Mar 2005, Randy McLaughlin wrote:
Trying to use 80 tracks can destroy your drive.
STOP IT!!!!
M'kay.
You should NEVER use it to boot DOS unless you get
Open-DOS and create a
driver for 8".
Why? It works fine.
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
2:44 a.m.
From: "Vintage Computer Festival" <vcf at siconic.com>
Sent: Sunday, March 06, 2005 12:56 AM
On Sat, 5 Mar 2005, Randy McLaughlin wrote:
PC's assume the drive has 80 tracks, 8" drives only have 77 tracks.
The drive has a sensor that limits track 00 but no sensor for track 77.
When you format the disk it starts at track 00 and tries to go to track 79
(80 tracks total). After track 76 (the 77th track) the stepper motor tries
to continue to step. This can damage the head or head alignment.
Some drives (such as Persci's) can do significant physical damage to the
drive.
You may want to clean your drive heads again if you started having more
errors. Also clean the rails the head assembly rides on.
Randy
www.s100-manuals.com
Trying to use 80 tracks can destroy your drive.
STOP IT!!!!
M'kay.
You should NEVER use it to boot DOS unless you
get Open-DOS and create a
driver for 8".
Why? It works fine. 
11:05 p.m.
From: "Vintage Computer Festival" <vcf at
siconic.com>
> So anyway, when I was formatting the disk, it didn't seem to like the last
> 4-6 tracks or so. Above the clatter of the noisy fan (bad bearings) I
On Sat, 5 Mar 2005, Randy McLaughlin wrote:
Trying to use 80 tracks can destroy your drive.
STOP IT!!!!
You should NEVER use it to boot DOS unless you get Open-DOS and create a
driver for 8".
Good call! I missed that...
8 Mar
8 Mar
6:18 p.m.
On Sat, 5 Mar 2005 20:43:03 -0600, Randy McLaughlin <cctalk at randy482.com> wrote:
Trying to use 80 tracks can destroy your drive.
STOP IT!!!!
You should NEVER use it to boot DOS unless you get Open-DOS and create a
driver for 8".
Does driver.sys in MS-DOS do the trick?
Eric
10 Mar
10 Mar
8:34 p.m.
On Sat, 5 Mar 2005 20:43:03 -0600, Randy McLaughlin
<cctalk at randy482.com> wrote:
> Trying to use 80 tracks can destroy your drive.
> STOP IT!!!!
> You should NEVER use it to boot DOS unless you get Open-DOS and create a
> driver for 8".
On Tue, 8 Mar 2005, Eric J Korpela wrote:
Does driver.sys in MS-DOS do the trick?
The versions of DRIVER.SYS provided by MS, or in PC-DOS, do NOT have a 77
track entry. But one or more of the MS-DOS OEM suppliers could have
created one; look particularly in V2.11 and V3.31
9:42 p.m.
Fred Cisin wrote:
No, but you can use a TSR BIOS patch (a memory-resident driver) to patch DOS
into making any diskette work (it doesn't rely on BIOS but rather the actual
geometry of the formatted disk). FDFORMAT comes with a small TSR to do this;
the once-popular 2M did this too. 2M even got into the Linux mtools
(http://man.he.net/man1/mformat for example). As for FDFORMAT and 2M, any
simtel mirror should have them...
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
Does driver.sys
in MS-DOS do the trick?
The versions of DRIVER.SYS provided by MS, or in PC-DOS, do NOT have a 77
track entry. But one or more of the MS-DOS OEM suppliers could have
created one; look particularly in V2.11 and V3.31
10:11 p.m.
>Does
driver.sys in MS-DOS do the trick?
Fred Cisin wrote:
The versions of DRIVER.SYS provided by MS, or in
PC-DOS, do NOT have a 77
track entry. But one or more of the MS-DOS OEM suppliers could have
created one; look particularly in V2.11 and V3.31
No, but you can use a TSR BIOS patch (a
memory-resident driver)
The BIOS does NOT need any patches.
DOS needs to be patched, or provided with an appropriate driver.
And to answer the SPECIFIC question
>>Does driver.sys in MS-DOS do the trick?
NO, the versions of DRIVER.SYS from MS or IBM do NOT do it.
to patch DOS
into making any diskette work (it doesn't rely on BIOS but rather the actual
geometry of the formatted disk). FDFORMAT comes with a small TSR to do this;
the once-popular 2M did this too. 2M even got into the Linux mtools
(http://man.he.net/man1/mformat for example). As for FDFORMAT and 2M, any
simtel mirror should have them...
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
5 Mar
5 Mar
10:08 p.m.
At 06:07 PM 3/5/2005, you wrote:
-Snip-
So anyway, when I was formatting the disk, it didn't seem to like the last
4-6 tracks or so. Above the clatter of the noisy fan (bad bearings) I
could hear the head recalibrating. When the format finished, it reported
107520 bytes in bad sectors. This comes out to 210 bad sectors (assuming
512 bytes per sector) which comes out to some weird number of tracks.
Aren't there supposed to be 26 sectors per track?
-snip again-
sounds like 4 bad tracks, plus a few bad sectors elsewhere..
10 Mar
10 Mar
5:28 p.m.
One other issue that can cause trouble with the "higher" track numbers is
write precompensation. As the track number gets higher you move closer to
the center of the disk and the bit density increases. Write precompensation
makes adjustments to the write data to compensate for the changes in bit
density. This would only be a problem though if you are using double density
(MFM).
Good luck, Steven C.
Ok, I finally found an 8" drive that worked. I don't think there's a
coincidence that it's half-height, and seems to have been made in the 1982
timeframe. I can't tell who the manufacturer is because I haven't
unbolted it from the chassis it's installed in to check yet.
I was able to format a disk mostly successfully (more on this in a bit)
and transfer MS-DOS 6.22 to it. It was pretty nifty booting DOS on my PC
off an 8" drive ;)
So anyway, when I was formatting the disk, it didn't seem to like the last
4-6 tracks or so. Above the clatter of the noisy fan (bad bearings) I
could hear the head recalibrating. When the format finished, it reported
107520 bytes in bad sectors. This comes out to 210 bad sectors (assuming
512 bytes per sector) which comes out to some weird number of tracks.
Aren't there supposed to be 26 sectors per track?
The main hurdle has been jumped, so I'm in good shape at this point.
Thanks for the tips, all!
7069
days inactive
7074
days old
15 comments
9 participants
participants (9)
-
cannings＠earthlink.net -
cctalk＠randy482.com -
cisin＠xenosoft.com -
eric＠brouhaha.com -
geoffr＠zipcon.net -
korpela＠gmail.com -
tomj＠wps.com -
trixter＠oldskool.org -
vcf＠siconic.com