PS/2 2.88MB floppy drive in an ATC mobo

[J.Clarke]

[This followup was posted to comp.sys.ibm.pc.hardware.storage and a
copy was sent to the cited author.]

Probably this has been already asked many times, but I am unable to
find a reference to it.

I have an almost new 2.88MB diskette drive, originally used on an
IBM PS/2 PC, which I would like to use with an ATX ASUS mainboard.
The drive has a 34-pin connector, visually identical to those of the
standard floppy drives, but no power connector. So I think it gets
the power from the 24-pin cable, which of course implies that the
pinout of this cable is not standard...

Where can I find some references about this ? I could build an
adapter, if only I had the relevant information.

Unless you already have floppies and old data you need to read,
don't
waste your time. 2.88M floppies are rare and expensive.

Here is a link to a normal floppy cable:
http://www.hardwarebook.net/connector/storage/internaldisk.html

I couldn't find one for 2.88M floppies.

The 2.88 meg drives also work fine as 1.44 meg drives and I've found
that using 1.44 meg diskettes formatted to 2.88 causes no problems.
OTOH, that's not much gain and a new diskette drive is 8 bucks, so
there's not much point to straining to use one.

If you really need the pinout for the cable, though, try asking on
comp.sys.ibm.ps2 and someone should be able to provide you either the
pinout or a link.

If you just want a diskette drive that can hold more than 1.44 meg try
an LS240--with the special diskettes it will hold 240 meg and can also
squeeze 34 meg onto a 1.44 meg diskette, but not in a way that is
convenient to use.

 

[Alberto]

Probably this has been already asked many times, but I am unable to
find a reference to it.

I have an almost new 2.88MB diskette drive, originally used on an IBM
PS/2 PC, which I would like to use with an ATX ASUS mainboard.
The drive has a 34-pin connector, visually identical to those of the
standard floppy drives, but no power connector. So I think it gets the
power from the 24-pin cable, which of course implies that the pinout
of this cable is not standard...

Where can I find some references about this ? I could build an
adapter, if only I had the relevant information.

Thanks for any info

Alberto

 

[Andrew Rossmann]

[This followup was posted to comp.sys.ibm.pc.hardware.storage and a copy
was sent to the cited author.]

Probably this has been already asked many times, but I am unable to
find a reference to it.

I have an almost new 2.88MB diskette drive, originally used on an IBM
PS/2 PC, which I would like to use with an ATX ASUS mainboard.
The drive has a 34-pin connector, visually identical to those of the
standard floppy drives, but no power connector. So I think it gets the
power from the 24-pin cable, which of course implies that the pinout
of this cable is not standard...

Where can I find some references about this ? I could build an
adapter, if only I had the relevant information.

Unless you already have floppies and old data you need to read, don't
waste your time. 2.88M floppies are rare and expensive.

Here is a link to a normal floppy cable:
http://www.hardwarebook.net/connector/storage/internaldisk.html

I couldn't find one for 2.88M floppies.

 

[Folkert Rienstra]

Probably this has been already asked many times, but I am unable to
find a reference to it.

I have an almost new 2.88MB diskette drive, originally used on an IBM
PS/2 PC, which I would like to use with an ATX ASUS mainboard.
The drive has a 34-pin connector, visually identical to those of the
standard floppy drives, but no power connector. So I think it gets the
power from the 24-pin cable, which of course implies that the pinout
of this cable is not standard...

Where can I find some references about this ? I could build an
adapter, if only I had the relevant information.

Just mount the missing 4-pin ps header and remove the surface mount
jumpers that connect traces from that header 5V pin to some pins in
the 34 pin connector ground (backward facing) row. They are usually
right next to the corresponding pins. Check with an Ohmeter.

 

[Folkert Rienstra]

[This followup was posted to comp.sys.ibm.pc.hardware.storage and a
copy was sent to the cited author.]

Probably this has been already asked many times, but I am unable to
find a reference to it.

I have an almost new 2.88MB diskette drive, originally used on an
IBM PS/2 PC, which I would like to use with an ATX ASUS mainboard.
The drive has a 34-pin connector, visually identical to those of the
standard floppy drives, but no power connector. So I think it gets
the power from the 24-pin cable, which of course implies that the
pinout of this cable is not standard...

Where can I find some references about this ? I could build an
adapter, if only I had the relevant information.

Unless you already have floppies and old data you need to read,
don't waste your time. 2.88M floppies are rare and expensive.

And sometimes they cost very little because of that rarity.

Because there aren't any.

The 2.88 meg drives also work fine as 1.44 meg drives

Some do and some don't. There are several incarnations, some
are automatic (internal switch decides mode) others deliver mode
state to the connector and expect mode back from controller.
Some FD controllers can provide the signal, others don't.
Then there is the issue of what pins these mode in- and outputs
are on, that isn't standardized either. Or what level they take.

and I've found that using 1.44 meg diskettes formatted to 2.88
causes no problems.

That again varies with drive make. The automatic drives will even
refuse to do that unless you drill a ED hole in the disk.

OTOH, that's not much gain and a new diskette drive is 8 bucks, so
there's not much point to straining to use one.

If you really need the pinout for the cable, though, try asking on
comp.sys.ibm.ps2 and someone should be able to provide you either the
pinout or a link.

There is no universal pinout for 2.88 drives.
It depends on the OEM that they were made for how they are configured.
There usually is a whole shitload of surface mount jumpers on these drives
to route the different signals to different pins and whether inverted or not.

 

[Andrew Rossmann]

If you just want a diskette drive that can hold more than 1.44 meg try
an LS240--with the special diskettes it will hold 240 meg and can also
squeeze 34 meg onto a 1.44 meg diskette, but not in a way that is
convenient to use.

Plus, the old LS120 and new LS240 can read/write 1.44M floppies about 2
to 3 times faster than a regular floppy drive.

 

[F. Robert Falbo]

Where can I find some references about this ? I could build an
adapter, if only I had the relevant information.

======================================================
From the "PS/2 FAQ" by Chris Feeny 02/20/1996

PS/2 34 pin Floppy pinout (not sure please verify)
Pin I/O Signal Pin I/O Signal
--- --- ------ --- --- ------
1 n/a Signal Return 2 o Data rate select 1
3 n/a +5V DC 4 n/a Drive Type ID 1
5 n/a Signal Return 6 n/a +12V DC
7 n/a signal ground 8 i -index
9 n/a Drive Type ID 0 10 o reserved
11 n/a signal ground 12 o -drive select
13 n/a ground 14 o reserved
15 n/a signal ground 16 o -motor enable
17 n/a Media Type ID 1 18 o -direction in
19 n/a signal ground 20 o -step
21 n/a signal ground 22 o -write data
23 n/a signal ground 24 o -write enable
25 n/a signal ground 26 i -track 0
27 n/a Media Type ID 0 28 i -write protect
29 n/a signal ground 30 i -read data
31 n/a signal ground 32 o -head 1 select
33 n/a Data Rate Select 0 34 i -diskette change
=======================================================
The old PS/2 FAQ is still available from TheRef(tm), which is
hosted by M.Farris & Assoc. as a link off their site...
http://marina.mfarris.com/theref/theref.html

...If you email me, I'll check my old PS/2 manuals to see if they
give better info.

 

[Alberto]

Bob,
thanks indeed for your pinout info, much useful.
If you have other information, as you seem to imply, please send them
to my email address, or post them here, many thanks.

Regards,
Alberto

 

[Alberto]

Bob,
the PS/2 FAQ link gives a 404 error. If you have a saved copy of the PS/2 FAQ,
would it be of too much disturb for you to send it to me ? Many thanks

Regards,
Alberto

 

[Alberto]

I found this page rich of info about the subject.
Just in case someone other is interested...

http://www.walshcomptech.com/ohlandl/floppy/floppy.html#Floppypinout

Alberto
P.S. Of course the ATC in my original subject line is a typo,
and must be read as ATX...

 

[Cheah TE]

| LS120 and new LS240 can read/write 1.44M floppies about 2
| to 3 times faster than a regular floppy drive.
but cost >10x !

I use a freeware from http://pages.prodigy.net/michael_santovec/files/slice.zip
to transfer big files ( split onto multiple floppies ).