17 Mar
2002
17 Mar
'02
6:14 a.m.
IIRC the Floppy on an Altos 580 is DSQD.
Am I correct that while different from standard
DSDD, they are *not* GCR drives?
What other machines might carry these drives, can I
hook one up to a standard PC controller in a box
running DOS, and then duplicate the disks?
I had one that had the CMI hard drive replaced with a
Seagate ST225. So I
know they will take similar configured Hard Drives. I think they will take
10, 15 and 20 Meg HDs.
This is good to know, ST225s still pop up from time to time...
-dq
17 Mar
17 Mar
7:10 a.m.
I just took a look at the docs for the Series 5 Altos computers and
there is a repair ticket for a Mitsubishi M4853 Disk Drive. The floppy
disk summary docs indicate that drive is a 5.25, HH, 720K, 96 TPI drive.
The CP/M version with my Altos 580 is 2.2 Licensed from Digital Research
by Lambda Software (4 disks.) Each of the six disks I have are labeled
double sided, double density, soft sectored. Of the two other disks, one
is for the 580-20 and is labeled MPM/CPM for Altos 580-20, the other
Altos Diags for model 580-x.
Hope this helps!
Douglas Quebbeman wrote:
IIRC the Floppy on an Altos 580 is DSQD.
Am I correct that while different from standard
DSDD, they are *not* GCR drives?
What other machines might carry these drives, can I
hook one up to a standard PC controller in a box
running DOS, and then duplicate the disks?
I had one that had the CMI hard drive replaced
with a Seagate ST225. So I
know they will take similar configured Hard Drives. I think they will take
10, 15 and 20 Meg HDs.
This is good to know, ST225s still pop up from time to time...
-dq 
8:20 a.m.
On Sun, 17 Mar 2002, Marvin Johnston wrote:
I just took a look at the docs for the Series 5 Altos computers and
there is a repair ticket for a Mitsubishi M4853 Disk Drive. The floppy
disk summary docs indicate that drive is a 5.25, HH, 720K, 96 TPI drive.
So, this means I can make disks from image with a vanilla 5.25 1.2M
drive, on a Linux box, right? Assuming I have DSDD floppies and use the
correct device (/dev/fd0D720) with dd?
Alternatively, is there any reason I couldn't temporarily move the
drive itself to a PC to build the disks?
The CP/M version with my Altos 580 is 2.2 Licensed
from Digital Research
by Lambda Software (4 disks.) Each of the six disks I have are labeled
double sided, double density, soft sectored. Of the two other disks, one
is for the 580-20 and is labeled MPM/CPM for Altos 580-20, the other
Altos Diags for model 580-x.
Any chance you could image those for me? Maybe even scan the docs?
Doc
8:57 a.m.
On Sun, 17 Mar 2002, Doc wrote:
So, this means I can make disks from image with a
vanilla 5.25 1.2M
drive, on a Linux box, right? Assuming I have DSDD floppies and use the
correct device (/dev/fd0D720) with dd?
Maybe. Does that driver successfully switch
step independent of switching
density?
If so, it might work IFF it happens to be the same number of bytes per
sector and sectors per track. It might be, but I'm not going to get a
chance to look that up today.
Alternatively, is there any reason I couldn't
temporarily move the
drive itself to a PC to build the disks?
With the right software,.. certainly.
For use in a PC with the stock PC cable, rejumper the drive to the second
drive select position (DS1 of 0/1/2, 2 of 1/2/3, B of A/B/C)
Lie to the CMOS and tell the PC that it is a 3.5" 720K.
You can test the drive then by putting a blank virgin 360K floppy in it
and formatting it as a 720K. (Note: a few people (Tony) have had
reliability problems using 360K blank diskettes as 720K, even though they
are spec'ed the same. It might be due to closer proximity to the
Greenwich meridian :-)
9:11 a.m.
At 01:20 PM 3/17/02 -0600, Doc wrote:
On Sun, 17 Mar 2002, Marvin Johnston wrote:
That MIGHT work but I don't recommend it. The 1.2M drive has
compatibility problesm with the 360k drives and it has the sme compatility
problems with the QD drive. You need a drive that's designed for QD and
you need QD disks if at all possible. QD disk have the same coercivity
(SP?) as 360k disks and 1.2M disks use a different coercivity.
Assuming I have DSDD floppies and use the
I just took a look at the docs for the Series 5 Altos computers and
there is a repair ticket for a Mitsubishi M4853 Disk Drive. The floppy
disk summary docs indicate that drive is a 5.25, HH, 720K, 96 TPI drive.
So, this means I can make disks from image with a vanilla 5.25 1.2M
drive, on a Linux box, right? correct device (/dev/fd0D720) with dd?
Alternatively, is there any reason I couldn't temporarily move the
drive itself to a PC to build the disks?
That should work as long as the PC understands the file structure. You
may need to use 22disk or something similar that understands the Altos
structure.
Joe
9:44 a.m.
On Sun, 17 Mar 2002, Joe wrote:
Actually, it is NOT the sme compatility, (nor the
same compatability :-)
problems. The big problem with 360K in 1.2M is the head width. THAT is
OK for "QD". But there can be some problems sometimes with trying to do
"QD" with 1.2M, since sometimes it can be difficult to get it to switch
density without also switching into "double-stepping" mode.
[Note: I'm not really trying to ridicule you about the spelling - at the
last Computer Faire and one year at Comdex, our sign maker
ignored the supplied disk file and delivered our signs saying:
"End disk format incompatility!"]
So, this
means I can make disks from image with a vanilla 5.25 1.2M
drive, on a Linux box, right?
That MIGHT work but I don't recommend it. The
1.2M drive has
compatibility problesm with the 360k drives and it has the sme compatility
problems with the QD drive. You need a drive that's designed for QD and
you need QD disks if at all possible. QD disk have the same coercivity
(SP?) as 360k disks and 1.2M disks use a different coercivity.
Correct spelling.
360K (AND "QD") is 300 Oerstedts; 1.2M is 600
Oerstedts.
Assuming I have DSDD floppies and use the
Pretty EXTREME assumption! Not much besides
CP/M,MP/M understands CP/M
file system and DIRectory structure.
correct device (/dev/fd0D720) with dd?
Alternatively, is there any reason I couldn't temporarily move the
drive itself to a PC to build the disks?
That should work as long as the PC
understands the file structure. You may need to use 22disk or something similar that
understands the Altos
structure.
or Media Master, or Uniform, or "certain others"
That "file structure" IS CP/M. MP/M is a variant in terms of OS
operations, with the same file system structures as CP/M. 'Course there
are a few thousand different CP/M disk formats.
--
Fred Cisin cisin(a)xenosoft.com
XenoSoft http://www.xenosoft.com
PO Box 1236 (510) 558-9366
Berkeley, CA 94701-1236
1:20 p.m.
On Sun, 17 Mar 2002, Fred Cisin (XenoSoft) wrote:
No, dd doesn't care in the slightest what the file structure is. I've
imaged disks with filesystems totally unknown to Linux with dd.
Blocksize is sometimes an issue, but I've found that setting blocksize
to "1" fixes that just fine.
Or, if I had a copy of 22disk (yeah, I'll google in a minute) I
suppose I could boot to DOS and do that. Does 22disk understand dd
images? (Andreas already cut to the chase & imaged a couple of trial
runs for me)
Doc
On Sun, 17 Mar 2002, Joe wrote:
Erck. That distant splash you just heard was the sound of Doc hitting
the bottom of the well. We passed the "All Greek To Me" phase awhile
back.
So. The "fd0h720" device on my Debian Linux machine is defined as
"/dev/fd0h720 5.25" 720K in a 1200K drive"
Will the 1.2M drive write reliable QD disks? Note that I said "write
reliable" not "reliably write". Several tries is no biggie.
That MIGHT work but I don't recommend it.
The 1.2M drive has
compatibility problesm with the 360k drives and it has the sme compatility
problems with the QD drive.
Actually, it is NOT the sme compatility, (nor the same compatability :-)
problems. The big problem with 360K in 1.2M is the head width. THAT is
OK for "QD". But there can be some problems sometimes with trying to do
"QD" with 1.2M, since sometimes it can be difficult to get it to switch
density without also switching into "double-stepping" mode. Correct spelling. 360K (AND "QD") is 300
Oerstedts; 1.2M is 600
Oerstedts.
Uh. OK. In dumbass terms, does that mean "no go"?
That should
work as long as the PC understands the file structure. You
Pretty EXTREME
assumption! Not much besides CP/M,MP/M understands CP/M
file system and DIRectory structure.
> may need to use 22disk or something similar that understands the Altos
> structure.
1:46 p.m.
On Sun, 17 Mar 2002, Doc wrote:
No, just DON'T use "High density" diskettes.
If you can find them, use diskettes rated for 720K usage.
If you CAN'T fine them, use 360K diskettes. Most of us have no problem
with using 360K diskettes, but SOME (including Tony) have had problems
with them. That might be due to his closer geographical proximity to
Stonehenge, or to the Greenwich meridian :-)
Erck. That distant splash you just heard was the
sound of Doc hitting
the bottom of the well. We passed the "All Greek To Me" phase awhile
back.
Sorry; some of the issues that came up do NOT matter for what you want to
do.
So. The "fd0h720" device on my Debian
Linux machine is defined as
"/dev/fd0h720 5.25" 720K in a 1200K drive"
Perfect!
Will the 1.2M drive write reliable QD disks? Note
that I said "write
reliable" not "reliably write". Several tries is no biggie.
Yes!
(with the right blanks)
360K (AND
"QD") is 300 Oerstedts; 1.2M is 600 Oerstedts.
Uh. OK. In dumbass
terms, does that mean "no go"? No, dd doesn't care in the slightest what the
file structure is. I've
imaged disks with filesystems totally unknown to Linux with dd.
Perfect!
Blocksize is sometimes an issue, but I've found
that setting blocksize
to "1" fixes that just fine.
Or, if I had a copy of 22disk (yeah, I'll google
in a minute) I
suppose I could boot to DOS and do that. Does 22disk understand dd
images? (Andreas already cut to the chase & imaged a couple of trial
runs for me)
It should be able to do it without any problems.
If not, contact me off-list and I'll help you.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
2:22 p.m.
On Sun, 17 Mar 2002, Fred Cisin (XenoSoft) wrote:
Alrighty then!
No, just DON'T use "High density" diskettes.
If you can find them, use diskettes rated for 720K usage.
The blanks I have are 3M "DS,DD Formatted Diskettes" IBM formatted at
360K. I gotta bunch, so a few failed formats won't stop the show.
'K. dd first, then 22disk if dd craps out.
Doc
On Sun, 17 Mar 2002, Doc wrote:
Oh, good. I was feeling very small.... ;^)
Erck. That distant splash you just heard was
the sound of Doc hitting
the bottom of the well. We passed the "All Greek To Me" phase awhile
back.
Sorry; some of the issues that came up do NOT matter for what you want to
do. So. The
"fd0h720" device on my Debian Linux machine is defined as
"/dev/fd0h720 5.25" 720K in a 1200K drive"
Perfect!
Will the 1.2M drive write reliable QD disks?
Note that I said "write
reliable" not "reliably write". Several tries is no biggie.
Yes!
(with the right blanks) 360K (AND "QD") is 300 Oerstedts; 1.2M is
600 Oerstedts.
Uh. OK. In dumbass terms, does that mean "no go"?
If you CAN'T fine them, use 360K diskettes. Most
of us have no problem
with using 360K diskettes, but SOME (including Tony) have had problems
with them. That might be due to his closer geographical proximity to
Stonehenge, or to the Greenwich meridian :-)
In Texas, you have to "hold your mouth right".
Or, if I had
a copy of 22disk (yeah, I'll google in a minute) I
suppose I could boot to DOS and do that. Does 22disk understand dd
images? (Andreas already cut to the chase & imaged a couple of trial
runs for me)
It should be able to do it without any problems.
If not, contact me off-list and I'll help you. 
1:59 p.m.
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6:21 p.m.
On Mon, 18 Mar 2002, Tony Duell wrote:
Standard Operating Procedure.
Which bits in particular are you having problems with?
Much of this
doesn't matter for your problem (because by your good luck everything is
compatible), but you might want to understand it all anyway.
Why it was germane to the issue at hand? I understand, at least
generally, the mechanics and relative formats of the drives and disks
involved, but the ongoing discussion was getting me to think there were
issues that I was completely missing.
I must admit I got no clue what an "Oerstedt" is. Or why I need to
know....
Will the
1.2M drive write reliable QD disks? Note that I said "write
reliable" not "reliably write". Several tries is no biggie.
Yes, it should be able to. But if you're in doubt, but can make a disk
which works (albeit that it might go unreliable in a month's time), just
back it up on the target machine. When I transfered some LS-DOS disk images to physical
disks for my TRS-80
Model 4, I had to write them on an 80 cylinder drive (the 1.2M drive on
this PC). I then backed them up to genuine 40 cylinder disks on the Model
4. Incidentally, I've never had any real problems writing TRS-80 40 or 80
cylinder images on a PC.
Kewl. I'm gonna have one someday. A TRS-80, that is.
Doc
18 Mar
18 Mar
3:01 a.m.
--- Doc <doc(a)mdrconsult.com> wrote:
I must admit I got no clue what an
"Oerstedt" is. Or why I need to
know....
Let's put it this way... it's another physical measurement of the
diskettes you want to use. Let's say someone from Europe told you
that you needed to use (and I'm approximating here) 133mm disks.
It's just another physical parameter. Mixing up 300 Oerstedt media
with 360 Oerstedt media is akin to wanting a 3" disk and trying to
use a 3.5" disk. The largest difference in that case is that you
can hold up the two sizes of disks and see plainly that one is not
identical to the other. With the wrong media coercitivity (but the
proper physical media size), it *looks* like it should work, but
when you go back for you data, it might not be there.
-ethan
__________________________________________________
Do You Yahoo!?
Yahoo! Sports - live college hoops coverage
http://sports.yahoo.com/
4:11 a.m.
At 06:01 AM 3/18/02 -0800, you wrote:
--- Doc <doc(a)mdrconsult.com> wrote:
> I must admit I got no clue what an "Oerstedt" is. Or why I need to
> know....
Oerstedt is a measure of how easy or difficult it is to magnetize
something. In this case, the magnetic media on the disk. It's **roughly**
the same thing that ohms are to current flow in an electrical conductor.
Drives are designed to create a certain strength magnetic field and you
need to match the magnetic media to that strength. It's important because
too strong a field can cause a disk can become so magnetized that a drive
can't erase or write new data to it and it has to be bulk erased. OTOH too
week field can leave a disk that has unreliable reads. Fortunately it's
usually real easy to right the right media since disk specifications are
pretty standardized. Just use the disk that's designed to operate with the
drive that you're using. Generally thre are only three types (in the 5
1/4" size); DSDD, DSQD and DSHD. The DSDD and DSQD disks both use 300
Oerstedt media but have 40 and 80 tracks (actually cylinders if you're
fussy about the correct terminology) respectively; DSHD (1.2M) also uses 80
tracks but uses 600 Oerstedt media.
I recommended that you try and find a QD drive but several people have
correctly (and vigorously!) pointed out that a 1.2Mb drive does use 80
tracks and that you COULD use one of them. (once you over come the possible
double stepping and write-strength pin select problems!) The problem is
that they use a different magnetic field strength and I've had that led to
trouble, partricularly in long term storage. For me it's easier to get the
CORRECT drive and media than it is to cobble something up that may or may
not work or be reliable!
Joe
Joe
2:11 p.m.
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7:57 p.m.
At 01:11 AM 3/19/02 +0000, you wrote:
There isn't. also, there is no problem with writing 80 cylinder single
sided disks in them (dec rainbow format) the HD drives step down to the
lower write strength when told to by software, be it RainDOS (the driver to
make a 1.2 MB Disk drive on an IBM compatible write dec rainbow disks or
commercial products to do media translation
I
recommended that you try and find a QD drive but several people have
correctly (and vigorously!) pointed out that a 1.2Mb drive does use 80
tracks and that you COULD use one of them. (once you over come the possible
double stepping and write-strength pin select problems!) The problem is
that they use a different magnetic field strength and I've had that led to
That's what the density-select pin is for. In one state (deasseted?), the
write current is correct for standard DD media (360K disks, etc).
There really should be no compatibility problems reading/writing 80
cylinder [1] DD disks in a 1.2Mbyte drive, provided you use it correctly.
19 Mar
19 Mar
8:45 a.m.
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18 Mar
18 Mar
7:32 a.m.
On Sun, 17 Mar 2002, Doc wrote:
Much of the discussion centered around issues that turned out to not be
relevant, such as whether the ALtos was MFM v GCR (MFM), sector size (you
got lucky with 512), sectors per track (you got lucky with 9), and what
kinds of problems COULD occur with writing 720K in a 1.2M.
Which bits in
particular are you having problems with? Much of this
doesn't matter for your problem (because by your good luck everything is
compatible), but you might want to understand it all anyway.
Why it was germane
to the issue at hand? I understand, at least
generally, the mechanics and relative formats of the drives and disks
involved, but the ongoing discussion was getting me to think there were
issues that I was completely missing. I must admit I got no clue what an
"Oerstedt" is.
The unit used for measuring coercivity (LOOSELY: magnetic sensitivity of
the disk).
Or why I need to know....
just part of the
explanation of WHY to use 360K v 1.2M blanks.
Kewl. I'm gonna have one someday. A TRS-80,
that is.
Mine are all gone. It HURT to part with them.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
1:53 p.m.
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17 Mar
17 Mar
6:01 p.m.
On Sun, 17 Mar 2002, Doc wrote:
On Sun, 17 Mar 2002, Fred Cisin (XenoSoft) wrote:
No, dd doesn't care in the slightest what the file structure is. I've
imaged disks with filesystems totally unknown to Linux with dd.
Blocksize is sometimes an issue, but I've found that setting blocksize
to "1" fixes that just fine.
Or, if I had a copy of 22disk (yeah, I'll google in a minute) I
suppose I could boot to DOS and do that. Does 22disk understand dd
images? (Andreas already cut to the chase & imaged a couple of trial
runs for me)
No, 22Disk does not understand dd images, TeleDisk images, .dsk images,
or most any other kind. It is only capable of reading, writing, and
formatting most CP/M disk formats. That is to say, it is capable of
formatting a DD blank as an Altos DSQD diskand and it is also capable of
writing available files to that disk. With a modification to the disk
definition and an image file of the boot track, it is possible to make
the new disk bootable also. This assumes that either the whole of CP/M
is on the boot track, or that any needed loaders and CPM.SYS or MPM.SYS
are written to the data area.
- don
On Sun, 17 Mar 2002, Joe wrote:
Erck. That distant splash you just heard was the sound of Doc hitting
the bottom of the well. We passed the "All Greek To Me" phase awhile
back.
So. The "fd0h720" device on my Debian Linux machine is defined as
"/dev/fd0h720 5.25" 720K in a 1200K drive"
Will the 1.2M drive write reliable QD disks? Note that I said "write
reliable" not "reliably write". Several tries is no biggie.
That MIGHT work but I don't recommend it.
The 1.2M drive has
compatibility problesm with the 360k drives and it has the sme compatility
problems with the QD drive.
Actually, it is NOT the sme compatility, (nor the same compatability :-)
problems. The big problem with 360K in 1.2M is the head width. THAT is
OK for "QD". But there can be some problems sometimes with trying to do
"QD" with 1.2M, since sometimes it can be difficult to get it to switch
density without also switching into "double-stepping" mode. Correct spelling. 360K (AND "QD") is
300 Oerstedts; 1.2M is 600
Oerstedts.
Uh. OK. In dumbass terms, does that mean "no go"?
That
should work as long as the PC understands the file structure. You
Pretty EXTREME
assumption! Not much besides CP/M,MP/M understands CP/M
file system and DIRectory structure.
> may need to use 22disk or something similar that understands the Altos
> structure. Doc
6:39 p.m.
On Sun, 17 Mar 2002, Don Maslin wrote:
No, 22Disk does not understand dd images, TeleDisk
images, .dsk images,
or most any other kind. It is only capable of reading, writing, and
formatting most CP/M disk formats. That is to say, it is capable of
formatting a DD blank as an Altos DSQD diskand and it is also capable of
writing available files to that disk. With a modification to the disk
definition and an image file of the boot track, it is possible to make
the new disk bootable also. This assumes that either the whole of CP/M
is on the boot track, or that any needed loaders and CPM.SYS or MPM.SYS
are written to the data area.
OK.
Did I mention "Thanks!" to everyone who offered advice & images? I'm
still looking for the "full set" and docs, but Being able to boot & test
is a great first step.
Thanks!
Doc
1:21 p.m.
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2:27 p.m.
On Mon, 18 Mar 2002, Tony Duell wrote:
Does any 1.2Mbyte drive do double stepping in
hardware?
Not that I've ever seen.
I've never seen
one that does (in fact most 'double stepping' drives have been modified,
they were not designed like that). And I've just checked the PC/AT BIOS
sources, and that machine most definitely double steps in software when
reading a 360K (40 cylinder) disk in a 1.2M (80 cylinder) drive.
The problem may be occurring (if it exists at all) from programmers trying
to interface with the existing software at too high a level.
One of my "colleagues" (competitors) was trying to do some stuff with DEC
diskettes and reported having problems with it. I never saw his source
code, but since he was trying for emulation with maximum OS transparency,
I'm going to guess that he was trying to use the MS-DOS API "raw
read"/"raw write" routines.
I also got two reports from users of getting (#64) "seek error"s when
trying to read Eagle diskettes in what they said were 1.2M drives. Those
users were unable to provide coherent followup, and had no problems once I
talked them through temporarily installing one of the Eagle drives (QD).
--
Fred Cisin cisin(a)xenosoft.com
XenoSoft http://www.xenosoft.com
11:05 a.m.
On Sun, 17 Mar 2002, Joe wrote:
At 01:20 PM 3/17/02 -0600, Doc wrote:
Our experience differs, Joe. I have never had a problem creating QD
disks on a 1.2 drive.
- don
On Sun, 17 Mar 2002, Marvin Johnston wrote:
That MIGHT work but I don't recommend it. The 1.2M drive has
compatibility problesm with the 360k drives and it has the sme compatility
problems with the QD drive. You need a drive that's designed for QD and
you need QD disks if at all possible. QD disk have the same coercivity
(SP?) as 360k disks and 1.2M disks use a different coercivity.
I just took a look at the docs for the Series 5 Altos computers and
there is a repair ticket for a Mitsubishi M4853 Disk Drive. The floppy
disk summary docs indicate that drive is a 5.25, HH, 720K, 96 TPI drive.
So, this means I can make disks from image with a vanilla 5.25 1.2M
drive, on a Linux box, right? Assuming I have DSDD floppies and use the
correct device (/dev/fd0D720) with dd?
Alternatively, is there any reason I couldn't temporarily move the
drive itself to a PC to build the disks?
That should work as long as the PC understands the file structure. You
may need to use 22disk or something similar that understands the Altos
structure.
Joe
1:16 p.m.
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12:01 p.m.
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12:54 p.m.
On Sun, 17 Mar 2002, Tony Duell wrote:
Working from failing memory (not recently refreshed), and I already said
that I would NOT get around to looking it up today, ...
If I Recall Correctly, the ALtos MP/M DOES coinscidentally just happen to
run 9 sectors per track with 512 bytes per sector (80 tracks per side)
'Course the DIRectory data structures are CP/M, and unrecognizable to
MS-DOS/Windoze nor any flavor of Unix.
correct device
(/dev/fd0D720) with dd?
Not necessarily. /dev/fd0D720 assumes a 'PC like
format' -- that is to
say 512 byte sectors, 9 sectors/track, double sided, 80 cylinders. You
could have some other sector size (256 byte sectors were very common at
one time, and I have seen 1024 byte sectors). You can almost certainly read/write these disks under
linux using the
FDRAWCMD ioctl(), but you'll need to understand the PC disk controller to
write software using that.
True.
Or one could just write the code to operate the 765, or call the INT13h
subroutines.
fiddling to do. In any case there's no reason not
to use a normal PC
1/3Mbyte drive.
Hmmm. Tony's definition of "normal PC" must differ slightly from mine :-)
I don't think that I have any 1/3M drives on hand. Although 320K/360K
is close enough to call it that.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
1:50 p.m.
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9:07 a.m.
I just took a look at the docs for the Series 5 Altos
computers and
there is a repair ticket for a Mitsubishi M4853 Disk Drive. The floppy
disk summary docs indicate that drive is a 5.25, HH, 720K, 96 TPI drive.
If anyone is ever in need of copies, I have technical
documentation and the maint. manual on both the M4853 and M4853-1
drives. It is a DSQD drive.
Jeff
--
Home of the TRS-80 Model 2000 FAQ File
http://www.cchaven.com
http://www.geocities.com/siliconvalley/lakes/6757
8:33 a.m.
On Sun, 17 Mar 2002, Douglas Quebbeman wrote:
Correct. (although being or not being GCR is irrelevant to the DRIVE) The
Altos diskettes that I'm familiar with are MFM "double density" (similar
to a "360K"), but with a narrower track providing 80 tracks at 96 tpi.
IIRC the
Floppy on an Altos 580 is DSQD.
Am I correct that while different from standard
DSDD, they are *not* GCR drives? What other machines might carry these drives, [?]
try:
http://www.xenosoft.com/fmts.html#720K
that is NOT an exhaustive list, merely the ones that I implemented in
XenoCopy.
can I
hook one up to a standard PC controller in a box
running DOS, [?]
YES.
You can do them with most 1.2M drives, with a few software complications.
But it IS easier if you hook up the right kind of drive, such as Teac 55F,
Tandon TM100-4, Mitsubishi 4853, Shugart/Matsushita/Panasonic/National
465. In which case, life is a little simpler if you lie to the CMOS and
say that they are 3.5" 720K.
and then duplicate the disks?
Maybe,
but NOT by using DISKCOPY, nor anything else that comes from MICROS~1!
With some calls to INT13h in a loop,...
or there were numerous commercial packages. (MY favorite is obvious)
--
Fred Cisin cisin(a)xenosoft.com
XenoSoft http://www.xenosoft.com
PO Box 1236 (510) 558-9366
Berkeley, CA 94701-1236
NOTE: My ISP is having difficulties. If you have problems reaching me at
this e-mail address, you can leave a message at:
fcisin(a)merritt.edu
11:57 a.m.
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ard＠p850ug1.demon.co.uk -
cisin＠xenosoft.com -
dhquebbeman＠theestopinalgroup.com -
doc＠mdrconsult.com -
donm＠cts.com -
erd_6502＠yahoo.com -
geoffr＠zipcon.net -
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marvin＠rain.org -
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