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486 problem

M

Meat Plow

Jan 1, 1970
0
Yes, but some would format ok, then quickly become unusable because
they didn't reliably support the higher data rate. That was why they
assigned different model numbers to what was basically the same drive,
but tested and certified to the RLL requirements.

The media in an RLL drive had a higher magnetic density.
 
E

Eeyore

Jan 1, 1970
0
Michael A. Terrell said:
The difference in the actual drives was that the media was tested and
certified for RLL.

I didn't know they did that too. It was a neat way to turn their 20MB drives into 32MB
for sure.

Read what I said, above and tell me I'm saying anything different.

Not disgareesing with you just brought a few memories back.

I'm curious that you said MFM controllers didn't work in 486s though due to speed
issues. The speed of the AT expansion bus was still 8MHz as long as you didn't tweak
it.

Graham
 
M

Michael A. Terrell

Jan 1, 1970
0
Eeyore said:
debug <enter>

g = c:8000 <enter>

IIRC

Graham


That was one way, but there were programs from several hard drive
manufacturers that did the low level format, verified the surface area,
followed by the high level format. It put the system files on the drive,
asked for the Volume Label, and exited with a bootable C: drive. Then
you installed DOS, Drivers and the programs you wanted. it could take
eight hours of inserting floppy disks before the job was done.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
I just installed a 486 board that someone gave me to replace a failed
386 into an old machine. There are programs on this machine that we
still use. The 486 board has Phoenix bios. Initially the setup option,
(F2) came up during post and allowed me to get into the bios to set
the drives up and the date. I did that and exited saving the
information. My 386 machine used an MFM controller board and I
plugged it into the new 486. The 486 however has an on board IDE
controller which it now occurs eto me perhaps should have been
disabled. So now when I try to boot it counts the ram and displays a
cache message but I get this message that reads : "last boot failed,
use default configuration". I assume that the default configuration is
part of bios but the problem is that the F2 option on startup is now
gone and I can't seem to get back into bios. I tried disconnecting the
battery and shorting across the ternminals on the board, and even
pulling the bios chip and shorting all the pins on a pad of aluminum
foil thinking that this may dump the memory, but nothing will get me
back. Does anyone know of a way to get back into bios after the
option no longer presents itself. Thanks very much for any assistance,
Lenny Stein, Barlen Electronics.

Might be easier just to get a machine designed to run with the mfm
card. Some 486s had no onboard IDE so you've got a fair range of
obsolete kit to choose from.


NT
 
E

Eeyore

Jan 1, 1970
0
Might be easier just to get a machine designed to run with the mfm
card. Some 486s had no onboard IDE so you've got a fair range of
obsolete kit to choose from.

Both 486's I had required separate IDE interface cards, the second being a VLB
type.

Graham
 
M

Meat Plow

Jan 1, 1970
0
Might be easier just to get a machine designed to run with the mfm
card. Some 486s had no onboard IDE so you've got a fair range of
obsolete kit to choose from.


NT

If you guys like me, like to browse through vintage computer junk, give
this site a try. It has some interesting links.

http://www.obsoletecomputermuseum.org/
 
Both 486's I had required separate IDE interface cards, the second being a VLB
type.

Graham- Hide quoted text -

- Show quoted text -

Does anyone have a good 16 bit MFM HDD/floppy controller thy would
wish to part with? I suspect that mine may be bad and I've called
everyone in the local Yellow pages. Thanks. Lenny.
 
M

Meat Plow

Jan 1, 1970
0
Does anyone have a good 16 bit MFM HDD/floppy controller thy would
wish to part with? I suspect that mine may be bad and I've called
everyone in the local Yellow pages. Thanks. Lenny.

I'll have a look in the attic. I know I have a couple Connor drives and a
big old Seagate up there along with a couple IBM ps/2 machines and some
other old junk.
 
Does anyone have a good 16 bit MFM HDD/floppy controller thy would
wish to part with? I suspect that mine may be bad and I've called
everyone in the local Yellow pages. Thanks. Lenny.

those are the wrong people, businesses wont have that kind of stuff.
Post a wanted notice somewhere to find the enthusiasts that have
historic junk sat in the loft. Some newspapers let you do this free.


NT
 
H

Homer J Simpson

Jan 1, 1970
0
Does anyone have a good 16 bit MFM HDD/floppy controller thy would
wish to part with? I suspect that mine may be bad and I've called
everyone in the local Yellow pages. Thanks. Lenny.

Typically I would try a computer recycler. You might get one for free since
they are not desired nowadays.



--
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A

Andy Cuffe

Jan 1, 1970
0
Does anyone have a good 16 bit MFM HDD/floppy controller thy would
wish to part with? I suspect that mine may be bad and I've called
everyone in the local Yellow pages. Thanks. Lenny.

If you can spend around $20-$25, there are a bunch on ebay. Computer
stores aren't likely to have anything that old. You need to find a
surplus electronics place.
Andy Cuffe

[email protected]
 
M

Michael A. Terrell

Jan 1, 1970
0
Does anyone have a good 16 bit MFM HDD/floppy controller thy would
wish to part with? I suspect that mine may be bad and I've called
everyone in the local Yellow pages. Thanks. Lenny.


I'll look around. I should have a few. (dozen)


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
T

tomh

Jan 1, 1970
0
Does anyone have a good 16 bit MFM HDD/floppy controller thy would
wish to part with? I suspect that mine may be bad and I've called
everyone in the local Yellow pages. Thanks. Lenny.
You could also try driving around on trash pickup day, if you still
have one in your community, and see what folks are putting out on the
curb. This can often be an excellent source for parts and repairable items.

tomh
 
G

Gary Tait

Jan 1, 1970
0
The 486 however has an on board IDE
controller which it now occurs eto me perhaps should have been
disabled. So now when I try to boot it counts the ram and displays a
cache message but I get this message that reads : "last boot failed,
use default configuration"

Disable the onbard IDE, the BIOS likely will see the MFM card.
 
Disable the onbard IDE, the BIOS likely will see the MFM card.

This one guy is telling me that because my original controller was a
WD 300 operating my Seagate drives and the drives were possibly set up
with that controller, that controller is the only one that I can use
to get into my drives. He says that even the Seagate controller which
I borrowed from someone and i have been trying to use will not work.
Does this sound reasonable?
 
J

James Sweet

Jan 1, 1970
0
This one guy is telling me that because my original controller was a
WD 300 operating my Seagate drives and the drives were possibly set up
with that controller, that controller is the only one that I can use
to get into my drives. He says that even the Seagate controller which
I borrowed from someone and i have been trying to use will not work.
Does this sound reasonable?


I have run into problems like that before, it's been years since I've
messed with MFM though so I'm a bit hazy.
 
J

jonpi

Jan 1, 1970
0
it is true that sometimes your drive will not work with a different
controller...the only way to know without having unavailable info is to
try it...beware as in many cases if you are trying something, do not do
anything like chkdsk since then you are not only trying, you are changeing

the reason is that the low level format program is on the bios of the
controller ... when you set up a disk you use the debug comand to run
the controllers "setup" program which low level formats the drive and i
guess the partition is set too... then it is ready to do the regular
high level format with DOS ... different controllers had slightly
different parameters sometimes so you can't just switch and expect to
read the drive set up on another type controller

the thing is that these drives lose the low level format over time ...
that is where spinrite allows you to
redo it without saving the data and putting it back

WD 300 ... does not ring a bell ... WD1003 does

and your drives are double spaced or single spaced, whatever one was the
little used format ... that does complicate things ... again info that
is in the past as far as my brain goes ... sorry

again ... SpinRite is the killer ap ... it low level formats or "renews"
the disk without hurting data ...
 
J

Jamie

Jan 1, 1970
0
This one guy is telling me that because my original controller was a
WD 300 operating my Seagate drives and the drives were possibly set up
with that controller, that controller is the only one that I can use
to get into my drives. He says that even the Seagate controller which
I borrowed from someone and i have been trying to use will not work.
Does this sound reasonable?
that is very possible, i remember years ago having problems like that.
you can get a controller with a different bias that was updateable and if
you formatted the drive with it, it's possible that would be the only
controller that would work on that drive.
how ever, I found that most of the time, if you had the same model
controller, and set up the same it would work fine.
 
L

Lionel

Jan 1, 1970
0
that is very possible, i remember years ago having problems like that.
you can get a controller with a different bias that was updateable and if
you formatted the drive with it, it's possible that would be the only
controller that would work on that drive.
how ever, I found that most of the time, if you had the same model
controller, and set up the same it would work fine.

Boy, this topic sure brings back dusty old memories! Yes, if you're
running MFM or RLL drives, you need to use the same brand & model
controller. Most of the time, a controller with the same chipset will
work, but you can't count on it. As long as you're careful not to
write (best to cut the *WR_EN line on the cable, as insurance) to the
drive you're trying to recover from, there's no harm in trying other
controllers.
The other problem in those days was that there was no standard way
for the drive to tell the controller or BIOS what
heads/cylinders/sectors numbers to use, which was often a real
nightmare if that data was lost from the CMOS memory. I always used to
write it on the case of the drive itself, so that it could easily be
found if the CMOS battery went bad. If you're lucky, so did the person
who installed the drive on this machine.
 
M

Michael A. Terrell

Jan 1, 1970
0
This one guy is telling me that because my original controller was a
WD 300 operating my Seagate drives and the drives were possibly set up
with that controller, that controller is the only one that I can use
to get into my drives. He says that even the Seagate controller which
I borrowed from someone and i have been trying to use will not work.
Does this sound reasonable?


There was no standard for 8 bit HD controllers, even with the same
manufacturer. 16 bit HD controllers were more compatible, as long as
they were for the same type of drive. You had MFM, RLL, SCSI, and a few
other interfaces/formats. The standard MFM or RLL card supported a pair
of drives and all you had to do was pair it up with the right class of
card. One BIG problem was that some 386 and most 486 motherboards were
too fast to support the MFM or RLL controller cards. The fact that the
motherboard has an IDE port makes it very likely that it can not support
a MFM or RLL drive, unless you set the CPU speed as low as possible.
Even then, it may be too fast. I keep a couple old 286 computers around
to transfer the data to IDE drives, and can be used in faster
computers. The early IDE controller cards gave you a choice of several
base addresses so you could add them to older computers without a
conflict. There was a great website called "The Ref (tm)" with a lot of
mirrored sites, but I can't find any of them that still exist.

Another reference is the "Pocket PC Ref" from Sequoia publishing:
<http://www.google.com/search?num=10...2006-31,GWYA:en&q="Pocket+PC+Ref"&btnG=Search>
that has a LOT of data on older drives. You have to know the number of
cylinders, heads and sectors to set up a MFM drive. There were a few
standard sizes in the BIOS, but most drives required a custom
configuration.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
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