1994 Method to Allow the
Sharing of I/O Port Addresses between a Floppy Disk
and an IDE Controller within a PS/2 Micro Channel
1994 Conversion Connector for the IBM Personal
of information on Intel's Site 2 Apr 08
National Semiconductor PC8477B
Out Capacitors (to the 8580 Common Devices page)
on 8580 Floppies (to the 8580 Common Devices page)
a Floppy in a 95
Disk on 1.44MB Floppy
System to Floppy Drive
to Manufacturer List
(82077SL) Floppy Controller
Media formats and
Planar and Drive pinout
2.88 Floppy to
Clone Hack Progress
Floppy Types (DisketteDrive[x]
* Marked 2.88MB Floppy
Function of Third
Error 165- Is The Floppy
8580 Floppy Drives
in the 95?
Floppy Under Setup
OS/2 MCA Foppy ADDs
OS/2 ver 3 and DMF
pin Floppy Header Pinouts
Floppy Security Circuitry
Commands (Registers- Lock, Unlock,
an Enhanced Command
The floppy controller and interface connector reside on
It is an NEC N82077SL, 68 pin SOIC. It seems
Intel bought the
chip rights from NEC.
The diskette drive controller supports:
o Four data transfer rates: -
250k / 300k / 500k / 1M bits per second
o Programmable precompensation
o A 16-byte FIFO buffer
o PS/2 Style 3.5' 1.44/2.88MB,
enhanced 2.88MB, 5.25" 1.2MB
o The secure media mode and the
82077SL internally samples the IDENT and MFM pin level
which is used to configure the operating mode (PC-AT,
Model 30, PS/2) on the falling edge of h/w reset.
Removal of DMA Request(DRQ) During an Under/Overrun
SL Power-on Reset Problem
82077AA/SL and the Floppy Drive
5. Sony MP-F40W - 14/15 There are dash 14
and 15 are two new
drives from Sony that handle 4 MB requirements. The
MP-F40W-14 has the DENSITY
SELECT 1, DENSITY SELECT 0 on pins 2 and 33
respectively, whereas the MP-F40W-15
has the DENSITY SELECT 1, DENSITY SELECT 0 on pins 2 and
As it is obvious from the table below, daisy chaining is
easily done if the
82077AA/SL is connected in the PS/2 mode (by typing
IDENT high) with either
type of drive, the only difference being the location of
DENSITY SELECT 0.
The 82077SL With The 82078 (44PIN)
The 82077SL WITH 82078 (64PIN)
95 and 90 Floppy Controller
These systems use the Intel 82077AA floppy
controller. The EE
floppy drive can be used on them, but the AA does not
support the EE functions.
9577 Bermuda Floppy Controller
These systems use either the 82077AA,
82077SL (rare), or the
NS PC8477AV floppy controller. Usually, systems with the
NS controller use
"*" marked floppy drives. BUT I have found some
82077AA/* combinations, plus
what I believe to be a late Bermuda with a 82077SL
floppy controller with
a * marked floppy on it...
From David Beem
Here is the listing of 82077xx FDC
chips that are able
to support the 2.88 EHD drives:
77 (Bemuda) Planar #1 Upgrade Intel
77 (Bemuda) Planar #2 Upgrade Cyrix
77 (Lacuna) Planar
85 (X, K, N) Planar
Type 1-Type 3
complex 82077AA (2)
1 Ed. All models support the 3.5"
Electronic Eject floppy drive. (and 2.88!!)
2 Ed. Known to support 2.88
Note: early 8595s do not support the 2.88MB
3 Ed. All N-Q support
the EE floppy (and 2.88!!)
One pattern seems to emerge from the
PS/2 planars: the "souped-up" or second-gen planars have
the 82077SL FDC chips. A couple of surprises though. I
did find two other FDC chips on my equipment. The first
on Bermuda planar #1 is a National Semiconductor
8477AV-2 chip *without* the
"(C) NEC 1979", but with "(C) NSC 1991". Probably a
82077AA replacement that
is reverse enginered enough to avoid having to use the
NEC copyright. That
system is unchanged from the way I bought it, with an
"*" 2.88 drive. The
spare 2.88 I got on eBay I am unsure of the original
model is a non-"*" drive.
There is a smaller surface mount
Intel 82091AA in my HP
NetServer that does bear the "(C) NEC'79" & also
"(C) Intel '86 '93".
Just a guess again about being a replacement for the
82077AA with the end
of the part number. All the Intel 82077AA and 82077SL
chips I have otherwise
have "(C) NEC 1979" & "(C) Intel '86 '91" of course.
Other clone motherboards
and adapter cards I have don't look like they have a
stand-alone FDC chip.
Most support the EHD drives in the BIOS, so it has to be
a variant of the
82077xx somehow (Even the enhanced NEC 72065B doesn't
support 2.88 drives.).
FDC chips are supposed to give which
level they are by
a "ver" command given to the chip. By my reference all
flavors of the 82077
return the same value. I have tried a routine for the
FDC ver command that
so far has *not* worked. The PS/2 35SX and 53 486SLC2
planars both give a
return value for a standard FDC that doesn't support
2.88 drives, then make
the computer unable
to read the drive! Here is the (of all things, BASIC)
routine anyway &
I am going to keep trying to get it to work.
OLDVAL = INP(&H3F5)
OUT &H3F5, &H10
FDCVER = INP(&H3F5)
FDC = ""
IF FDCVER = &H80 THEN FDC = "NEC
765 / Intel 8272 or
compatible FDC, no 2.88 support"
IF FDCVER = &H81 THEN FDC = "Intel
82077xx or compatible FDC, 2.88 support"
IF FDCVER = &H90 THEN FDC = "NEC
72065B or compatible FDC, no 2.88 support"
IF FDC = "" THEN FDC = "Unknown FDC
returning value " + HEX$(FDCVER)
OUT &H3F5, OLDVAL
Planar Floppy Types
If you look at the DF9FF.ADF, you will see:
DisketteDrive=1 2 4
What is the code, Kenneth?
Tim N. Clarke rises from the mists:
1 5.25, 360KB
2 5.25, 1.2MB
3 3.5, 720KB
4 3.5, 1.44MB
6 3.5, 2.88MB
7 Floppy Tape
This is sometimes useful to add diskette support for a
specific size/capacity. The one incident
Tim Clark boasts:
Anyway, the point of all this is that I
found that the 1.2MB could be configured as "Drive B:"
by editing the system ADF to add the 5.25" drive codes,
provided that the later version of SC.EXE (V2.20?) was
Formatting 720K Disks on a 1.44MB
>Why don't you use format /f:720 in the DOS window to
make the 1.44 disks
720k suitable? Maybe the 720k machine can't read them
later, but this depends
on the drive. 720k drives write wider tracks than 1.44 do.
Peter blearily looks up from his bowl of Fruit Loops 'n
Guess I jump in here and clear some misunderstandments.
1. Older PS/2 are non-media sensing -
means: whether the floppy
has the right-hand "media type hole" or not doesn't
bother these machines.
2. "Klone Chop-Suey-PCs" use to have FDDs
that *do* test for
the media type hole - and consequently refuse to read
from a down-formatted
1.44MB floppy. You *need* to use a piece of transparency
tape around the
front edge and cover the hole from the *underside*. This
does not have any
effect on the older PS/2s as
explained in 1. above. The "generic" FDDs use a set of
switches on the right side to test for a) floppy
presence and b) presence of a "High Density" hole.
(2.88MB drives have a third switch that tests for "eXtra
Density" hole, which sits a bit further away from the
lower edge of the floppy). Some older PS/2 FDDs have the
switches too - but they are used for media presence only
not for detecting the media type, like e.g. in a Mod.
50/60, 55/65, 70/80 and the 30-286.
3. If you'd closed the media type hole on
am actually 1.44MB
formatted floppy and try to format it on a "non PS/2"
machine it might complain
on a false format in a first attempt. You better use a
PS/2 (see 1. ) On
DOS after 3.x you need to use FORMAT A: /U /F:720 to
format to 720KB. On
DOS 3.x you need to use FORMAT A: /N:9 /T:80 to force a
The /U parameter in later DOS (and Win95
DOS box) does an "unconditional" format and ignores all
data and formats on the floppy.
It does a *physical* format across all sectors and
actually writes the 720K
structures at all. If you would use the /Q
parameter the drive would
only try to rewrite the first sectors with the File
Allocation Table (FAT)
on that floppy and leave the rest untouched - that will
not work and will
result in a media error anyway. The /N:9
parameter on older
DOS is the difference between 720K and 1.44MB format.
Both use 80 tracks
(the /T:80 parameter), but 1.44 uses 18 sectors
(would be /N:18), while
720K uses half of them - therefore /N:9.
The *track width* is the same on 720 and
1.44 format - because
both use 80 tracks and the stepper motor does the same
step-width - and the
R/W-head gap does not change during the process ... :-)
Once you'd formatted a 1.44MB floppy to
720KB you might be unable
to re-format the floppy back to 720KB - even if you
remove the covering tape
from the media type hole. 1.44MB floppies use a
Ferro-Chrome (FeCr) base
material, which "holds" the magnetism a bit stronger
than the Ferrite-Oxyd
(FeO) material usually used for 720K floppies. The R/W
amplifier on generic
FDDs might be unable to fully erase the 720K format in
Formatting 3.5" to 360KB
Once again, Peter slips up by saying:
Old PS/2 that do not care (much) for the
floppy formats and
use an older DOS (like Mod. 50/60, 55/65, 70/80 with DOS
3.3 to 5.0) can
be convinced to format a 3.5" floppy to 360KB with using
FORMAT A: /N:9 /T:40
.... if you then have a machine with a 5.25" drive as
well (as on my good
old trusty Mod. 80-A21) you can use DISKCOPY B: A: to
make 3.5" copies from
the 5.25" disks onto 3.5".
Interestingly, most machines support 3.5" /
360KB format and
can at least read it.
to Floppy Drive List
This list does not mean that you cannot use a
later drive on
an older system. That is determined by the BIOS of the
system. I do not know
the limits of all these models.
EE = Electronic
7568 Floppy Drive
1.44MB 15F7503 (Damn 32 pin tape connector!)
8535/8540 Floppy Drives
2.88 92F0132 (EE) Do these have 82077SL?
8550 Floppy Drives
8555SX Floppy Drives
8556/8557 Floppy Drives
8560, 8565, 8580 Floppy Drives
1.44 64F0162 (Pin Conn. LED below slot)
1.44 72X8523 (Edge Conn. LED above slot)
8570 Floppy Drives
8570/8573 (P70/P75) Floppy
1.44 64F0162 (Not listed, but will also fit, and is
8590 Floppy Drives
2.88 64F4148 Not listed, but useable. See Warning below!
2.88 92F0132 (EE) Not listed. Does not have a 82077SL
2.88 64F4148 Not listed, but useable. See Warning below!
9556/9576 and 9557/9577 and i/s
2.88 92F0132 (EE) Bermuda 56/57 planars lack 82077SL.
Does not support EE.
Floppy FRU to Manufacturer List
List is NOT complete. Remember that an FRU
can refer to many
1.2MB Floppy FRU to
64F4102 (Electronic Eject)
1.44MB Floppy FRU vs.
64F0162 (Pin Conn. LED below slot)
ALPS DFP723D12F (32 pin tape connector!)
2.88MB FRU vs. Manufacturer
Mitsubishi MF356F-899MF Asterix Marked!
ALPS B12HP004113 Possibly Japanese models
only (Thanks, Sandy!)
Mitsubishi MF356F-815MB (Uses clone-like
short floppy eject
2.88 92F0132 (Electronic Eject)
Sony MP-F40W-07 (also marked
64F0206 vs. 64F4148
These have no grey plastic sled undersides
but the metal mounting
plate with integrated side rails. I think that's the
major difference between
don't you mean 64F0204?)
and 64F4148 .. if you look into EPRM you will find that
all -4148s are for
35/40, 56/57 and 76/77 - while the -0206 is for the Mod.
Model 85/90/95 Floppy Drive Slide
of 2.88 vs 1.44
This was derived from Intel
Super Dense Floppies . The artwork is from this
intel document, I just
cleaned them up a bit.
Toshiba has taken the 2 MB floppy and
doubled the storage capacity
by doubling the number of bits per track. Toshiba
achieved this by an innovative
magnetic recording mode, called the vertical or the
mode. This mode utilizes magnetization perpendicular to
the recording medium
plane. This is in contrast to the current mode of
longitudinal recording which
uses the magnetization parallel to the recording plane.
By making the bits
stand vertical as opposed to on their side, recording
density is effectively
doubled, Figure 1. The new perpendicular mode of
recording not only produces
sharp magnetization transitions necessary at higher
but is also more stable.
2.88MB Floppy Construction
The 4 MB disks utilize barium ferrite
coated substrates to achieve
perpendicular mode of magnetization. Current disks use
cobalt iron oxide
(Co-g-Fe 2 O 3 ) coating for longitudinal recording. The
barium ferrite ensures
good head to medium contact, stable output and
durability in terms of long
use. High coercivity is required to attain high
recording density for a longitudinal
recording medium (coercivity specification of a disk
refers to the magnetic
field strength required to make an accurate record on
the disk). A conventional
head could not be used in this case; however, the barium
ferrite disk has
low coercivity and the conventional ferrite head can be
The new combination heads include a pre-erase mechanism,
i.e., the ferrite
ring heads containing erase elements followed by the
read/write head. These
erase elements have deep overwrite penetration and
ensure complete erasure
for writing new data. The distance between the erase
elements and the read/write
head is about 200mm. This distance is important from the
floppy disk controller
point of view and will be discussed in later
The implementation of 4 MB drives requires
Gap2 (see Figures 2a and 2b) and VCO timing requirements
unique to these
drives. These new requirements are dictated by the
design of the ``combination
head'' in these drives. Rewriting of disks in the 4 MB
drives requires a
pre-erase gap to erase the magnetic flux on the disk
preceding the writing
by the read/write gap. The read/write gap in the 4 MB
drive does not have
sufficient penetration (as shown in Figure 4a) to
overwrite the existing
In the conventional drives, the read/write
gap had sufficient depth and could effectively overwrite
the older data as depicted in Figure 4b. It must be
noted that it is necessary to write the conventional 2
in the 4 MB drive at 500 Kbps perpendicular mode. This
ensures proper erasure
of existing data and reliable write of the new data. The
pre-erase gap in
the 4 MB floppy drives is activated only during format
and write commands.
Both the pre erase gap and read/write gap are activated
at the same time.
As shown in Figure 4a, the pre-erase gap
precedes the read/write
gap by 200mm. This distance translated to bytes is about
38 bytes at a data
rate of 1 Mbps and 19 bytes at 500 Kbps. Whenever the
read/write gap is enabled
by the Write Gate signal the pre-erase gap is activated
at the same time.
There is a outfit called WSG Group (site is
under heavy construction)
that is a high volume diskette supplier. They
currently have over 600,000
finished, ready to go diskettes, 2DD; 2HD; and 2ED.,
with a back-up
of raw materials of over 2 Million diskettes awaiting
They have in-stock the following:
New--Duplicator Grade ED 3.5 diskettes...
Recycled--ED Diskettes---3M, Maxell, Fuji
All of diskettes are pre-certified and formatted
offer a lifetime guaranteee..
The ED Diskettes are priced as follows:
50pk bulk bag
To order from single pack to volume quantities, email John Schattin
The listed prices
DO NOT include shipping. But how heavy is a box of
Resistor Network by 95A Floppy
Bourns 4816P-002 -103 (bussed 10k ohm) Spec sheet HERE.
Marked 2.88MB Floppy
I just noticed that the 2.88 floppy drive in
one of my PS/2
machines has an asterisk (*) printed on the top side of
the blue eject button.
Anybody has a clue as to what that might indicate? Is it
just there for looks?
The drives with the asterisk are those for
35/40, 56/57 and
76/77 - but *not* for 85/90/95. Should be a 64F4148,
while the "others" use
a 64F0204. They differ slightly in the
pinout and can damage the
planar on earlier Mod. 90 / 95. (Ed. I'm
using an asterisk 2.88 on my 9590. Note that this is a later
Hi Al !
>9595 floppy is FRU 64F0204. Floppy I have that is
mounted to the sled is FRU 64F4148. Can I use this
floppy on my 9595/8595 without fear?
That 64F4148 is the 35/40, 56/57, 76/77
FDD. If you really like
your 95 you *do not* try it in there. A team mate once
did it ... and it
took us some days to solder in a new FDD-controller ...
(main problem was
to find one at first)
I cannot figure out *exactly* what caused
the mess, but it has
to do with the "security features" available on the 95 -
and the corresponding
pins on the 56 - 77 being not present and set to GND.
For the older 8595
IBM published a warning, that use of the inappropriate
FDD could permanently
damage the sysboard.
From Us, The god-Emperor of Microchannel (The royal
I whipped out my asterix marked FRU
64F4148. It's a
Mitsubishi MF356F-899MF. I just pulled my stock 2.88
from my Bermuda planar
9577- it is a 64F4148 as well, BUT the Mitsubishi model
First postulation of the "Law of the Asterix" (you heard
it here first, folks!) is that the MF356F is the model
that is incompatible with early 90s/95s.
As noted above, I have used the " * " floppy on a
9590 with no unusual
results. I figure that there must be a more primitive
floppy controller used
on the 35/40 etc. systems. I do not have one of these to
Visual Differences Between
M356C and M356F
BTW: the most obvious difference between
Mitsu MF356C-799 and
-899 is that -799 has a longer upper cover and the
connector on the left
side (looking at the rear), while the -899 has a shorter
upper cover and
the connector on the rear right side.
So they differ a lot through the mechanism
of the head actuator stepper motor). For the electronics
part - I can't say.
Floppy Connector Purpose
> I noticed that the diskette drive connects to the
motherboard using some
sort of strange connector. It appears to be about
44 pins or so (compared
to the SCSI connector), and the ribbon cable has *3*
plugs coming off it.
I never heard of anyone putting 3 diskette
drives in a machine
(let alone a PS/2), and diskette drives use 30 (?)
pins. So what are
the extra pins and connector for?
The Mod. 56 / 57 / 76 / 77 / 85 / 90 / 95
use a somewhat different
FDD-connector on the planar. They have the Type-3
FDD-interface, which also
supports 2.88MB drives ("Media-Sense Drives"). The third
connector is for
a very odd ITBU Internal Tape Backup Unit, which was a
IRWIN 120MB tape. The machine supports only 2 FDDs - as
Ed. Configuring The
82077 For Tape Drive
The FDD-plugs are 34-pins (2 x 17), only
the planar connector is a bit strange 44-pins. This type
of interface contains also lines for security
control, i.e. in connection with the "Electronic Eject
2.88MB FDD", which
can be locked and password protected.
Tried to find a pinout of the connector but
haven't found any
at the moment ...
Reports 165- But Is the Floppy Working?
From Tim Clarke
>b) the floppy controller/drive/cable is suspect and
needs looking at.
However, one would have expected a 601 error is things
were really bad.
Not always. A disfuntional FDD may as well
cause a 165. "It
is configured - but does not respond". If the heads
stuck, do not pass Track-00
tests or have RDATA stuck high or such you will surely
get a 600-series error.
But if the drive has a "DC leak" and simply appears as
absent it is judged
as "device missing but still present in the
Pin Floppy Drives
From Fred Spencer
These pin style diskette drives can be
sub-divided into two
sub-groups. The original model 8580 drives are
identified by the P/N 90X6766.
I have seen these drives labeled as manufactured by
Mitsubishi, Alps Electric
and YE Data. Later models were produced for the 8595 and
they are identified
by the P/N 72X6112 or 1619618 and also sometimes
accompanied by the FRU #
64F0162 , which is also the FRU # reported in the HMM
(October 1994) for
both the 8580 and the 8595. HOWEVER, I have discovered
that although the
8595 drives (FRU #64F0162) will work on the 8580, the
8580 drives (P/N 90X6766)
will NOT work on
the 8595!! The
drives with FRU # 64F0162 have also been labeled as
manufactured by Mitsubishi,
Alps Electric and YE Data.
Disabling Floppy under Setup
Even if you use the selectable boot and
remove the 1.44, A:
drive from the boot sequence, there is a "safety" device
that always looks
at the A: drive for a Reference Diskette. If there
is a Reference Diskette
in the drive it will override "selectable boot"
After the installation of OS/2 Warp and OS/2 Warp
file contains two diskette-driver statements: IBM1FLPY.ADD
Only one of the drivers is loaded; the other just takes up
disk space. On
MCA machines, you need IBM2FLPY.ADD. You may delete
* IBM1FLPY.ADD with /MCA works on the IBM PS/2 Micro
* If installation is from DMF diskettes, use IBM1FLPY.ADD
/MCA for PS/2 MCA
Microsoft has confirmed they have changed
thier compression utility
for windows products now shipping. The type of
compression is not recognized
by OS/2 3.X on some older PS/2's. For example, some
model 80, 70 and 65 machines.A
programming error was found but will not be corrected.
It is a permanent
1. In config.sys
2. If above does not work then use following
BASEDEV=IBM1FLPY.ADD /MCA /A:0 /U:0
The diskette drive cable converts a 2- by
22-pin connector on
the system board into three 2- by 17-pin connectors for
attaching internal diskette drives. The cables pass
control and data signals between the diskette drive
controller on the system board and the drives. They also
power to each drive.
Note The 3.5-inch
drives are required to support media-sensing.
System board 44 pin connector
pinout (95A and
Data rate select 1
+5 V dc
Drive type ID
1/Drive status 1
Media type 0/Drive
+12 V dc
Drive Type 0/Drive
-Head 1 select
Data rate select 0
-Drive select 0
Drive select 1
-Motor enable 0
Media type 1/Drive
-Drive select 2
-Motor enable 2
Header (Media Sense)
Data rate select
Drive type ID 1/ Drive Status1
Drive type ID 0
Media type 1/ Drive status 3
Media type ID 0/ Drive status 2
-Head 1 Select
-Head 1 select
Data rate select
Floppy to Clone Hack
Just when you thought it couldn't be done...
This is not a 100%
reliable way to hack the 2.88, BUT it shows that a strong
From Sören Hedlund
Since Febr I`ve tested with Sony
MP-F40W-03 - and still
working on these machines, so I dont beleive there is a
Yes, 1.44 disk works fine, but not 720 - you loose about
5% when formatting.
However, I also had to make a circuit to make these Sony
MP-F40W-03 to work
properly with all three formats.
Tested MB with IBM 2.88:
Tyan S1572 ATX
- SMC fdc37c669qf p
- SMC fdc37c932apm
QDI TITANIUM 1 -
Asus PVI-486SP3 -
- Winbond W83877TF
(Hot Shuttle Hot-433 - UMC um8663af -- No
(Compaq PRESARIO - not in bios - No 2.88 !)
So if BIOS support 2.88 it does not mean it will
I/O - chip must support it as well.
From Joseph Realmuto Jr
The first is a 386-40
with a SIDE4 HP multi-IO
card(2.88MB capable floppy controller). Since this
machine does not have
built-in 2.88MB support I had to use a TSR which updates
the computer's bios.
The floppy controller on the card is capable of 1 Mb/sec
connected pins 34, 32, 30, 28, 26, 24, 22, 20, 18, 16,
12, 8, and 2 on the
P/S2 floppy to the corresponding pins on the
controller. I left pins
4, 6, 10, and 14 on the floppy unconnected. Pin 3
of the floppy was
connected to +5V and pin 11 to ground. The floppy
is a Sony MP-F40W-03
connected as the B drive(the A drive is a standard 1.44
MB). The floppy reads,
writes, and formats 2.88MB media. I can also
format 1.44MB media to
2.88MB without drilling an extra hole in it. In
fact, all media is
automatically formatted at the drive's native
unless forced with the /F switch. I was not able
to get a Mitsubishi MF356F-899MF drive to work on this
machine (pins 26 and 34 seemed to oscillate, and the
computer said there was a seek error).
The second is a Packard
Bell Pentium machine
with an Intel Triton chipset and an on- board 2.88MB
capable floppy controller.
I used the above Mitsubishi floppy(again as the B drive)
and this time simply
used an edge card adaptor which connects only the top
and pin 1(ground). I added +5V on pin 3 by
soldering a wire from one
of the hard drive power plugs. Again, this floppy
works just as well
as the one on the 386 machine. It also seems to
at its native capacity regardless of which meda is
actually in the drive
unless forced with the /F switch.
It seems that pins 4, 10, and
14 can be left either
connected or unconnected(I recommend leaving
unconnected). Pin 6 should
be either connected to pin 6 on the controller (which is
an N/C on clone
controllers) or left unconnected. It should never
be connected to +12V
even though this is in the pinout for the P/S2 floppy
for two reasons: 1)+12V
is not used at all by the floppy drive 2)On
some (Sony MP-F40W-15)
pin 6 is DENSITY SELECT 0 and putting +12V on a 5V logic
line can fry the
drive, controller, and possibly even the
As a last note, the 1.44MB
media seems to work well
at 2.88MB. It formats error-free and seems to hold
data with no problem.
I am doing some long-term testing to see if it will
retain data. At
this time I do not recommend putting anything important
on these media.
me if you know of anybody who has tested this long
From David Beem
As I am building up from the basics I
am not having too
much trouble so far. Having learned not to assume on my
or anyone's theories
I am slowly gaining information to see if I can pull
this off. I pulled out
my Model 35SX, disconnected the 1.44M & connected
the spare (non-"*")
2.88 drive. After the expected 16x error I have it
configure itself &
I am up and running with a 2.88Mb A: drive on a 386SX-20
Even like the guy said on your page that he was able to
format a standard
HD disk as EHD with no complaints. Mine differed in that
I had to tell it
with the /F:2.88 switch, otherwise it formatted it as
1.44Mb (that was expected,
but not *assumed* on my part).
I am using some pretty cheap bulk
floppies too. I don't
know how long the information will last, but it is good
to know I can test
the EHD media without having to find the exact diskette
out there. The Model
35SX uses a 82077 controller as well. As luck would have
it I also have an
ISA Adaptec 1542 SCSI board with an onboard 82077 floppy
I can cross-check the IBM planars to it too see the
With the 1.44Mb PS/2 floppy drives
IBM moved one ground
and one unused pin to put the 5 & 12VDC power on the
By my references they seem to have inverted a half-dozen
too, but left them in the same relative position on the
the Sony board with 3 circuit trace cuts and 3 jumpers
to account for the
power connections at least allows the clone to power up.
The Motor Enable
signal (one of the ones on the "twist" of the cable) is
not inverted, so
it spins the drive up when a read from the floppy is
given. The stepper moter
doesn't move though because that is one of the inverted
I am going to see which buffer chip
is used to invert the
signals between the Adaptec board and the IBM planars.
There is probably a
riser with the correct buffer chip(s) I can assemble to
do the task with a
little work. At least at the drive end the connector is
pretty much the same.
What I have seen is that at the IBM planar end the Model
35, 40, & 53
have a 40-pin connector and the Model 56, 57, 76, &
77 have a 44-pin
connector. I will figure out the pinouts for those
The diskette drive
controller uses a FIFO buffer to enhance DMA transfer
operations. The FIFO buffer is
used in the data transfer phase only, and its operation
is transparent to
The diskette drive
controller in this system supports the optional 2.88MB
enhanced diskette drive, which has
a media-security feature. This diskette drive supports
Lock, Unlock, and
Eject commands; the Lock command inhibits diskettes
from being removed or
inserted. Additionally, if the privileged-access
password is set and the
diskette drive is in the boot path, the drive is
FRUs I have seen for the 2.88MB
enhanced diskette drive 92F0132, 92F0129, and I saw
82G1888 mentioned as well.
The secure media mode
allows the diskette drive to receive enhanced
commands. These commands provide a means of
controlling access to the media in the diskette
drives. Through these
commands, programs can eject a diskette or disable the
mechanism, which inhibits
media from being removed or inserted.
To determine whether the mode and
are supported for a specific drive:
1. With the enhanced-command
bit set to 1, test the state of the drive type (1,0)
signals by reading the Drive Status
Note For info on enhanced-command bit,
refer to System Control
Port C (Hex 007C).
the enhanced-command bit set to 0, retest the state of
the signals. If the
signals change to a binary 11, the mode and commands
are supported for that
Electronic Eject Floppy
with eject button or sofware
1 Eject via
An optional 2.88 MB diskette drive with security
is available on some IBM PC Server systems. The
diskette drive is a
3.5-inch, one-inch high drive with media sense
capability for the standard
diskette capacities of 720 KB, 1.44 MB, and 2.88
MB. It can read and
write data up to a formatted capacity of 2.88 MB, while
and write capability with 720 KB and 1.44 MB diskette
A control signal has been added to the
diskette interface that
supports LOCK, UNLOCK, and EJECT commands issued by the
If the privileged-access password is not set, the
diskette is unlocked during
POST. If the password is set, the boot process
does not unlock the
diskette drive unless it is the designated IPL source.
an operating system
utility. For SCSI devices, there is a proposed
standard UNLOCK command.
In this case, the operating system will control the LOCK
command if the privileged-access
password is set. Access to the unlocking function
with specific user
authorization can be controlled by secured system
In the event of power loss, the system
retains its state (secured
or unsecured) independent of the state of the
battery. A diskette can
be inserted in the drive, but it cannot be removed if
the power is off.
When the drive is turned on and locked, the media cannot
be inserted or removed.
Enhanced 2.88MB Floppy Security
>1. Do all floppy controller
chips have the
ability to pulse the leading edge of the of the
security cmd signal?
the later machines support the security functions. It
has been offered for the 9595 and 9585 at least. The
EE 2.88MB drive comes in two "flavours": 92F0129 for
and 9595A, 92F0132 for 35/40, 56/57 (all), 76/77 (all)
For the later group I
can tell, that
the 35/40 and 8556/8557 have no security features
integrated, most likely
the 9556/9557 and "Bermuda" 9576/9577 lack the feature
too. The FDD interface
on these machines is a bit different from those on the
the Server 77i had these security features mentioned
in early flyers. So
it appears as if the "Lacuna" machines *have* the
controller logic. (Ed.
The 82077SL FD
controller has the extra circuitry that supports
>2. Is this a hardware function
of the controller?
Yes. But requires
>3. Can this be controlled by
software (thru BIOS) on any controller?
There was a tool I cannot recall the name from, which
could "lock" the EE-FDD function. You could neither
insert a Floppy when it is empty, nor pull one out if
is one in the drive. I think they use a logic gate
programmed on the controller
to stop the motorized eject / load function.
I think what
the announcement (and Peter et al.) talked about was
software to *cause* the floppy to eject *not*
prevent/disable the feature, although I won't swear to
this. I would think the physical switch is your only
option for that. I have the 'electronic
eject' 5.25" slimline floppy in one of my 95s and none
of the PC-DOS 7 DRVLOCK
/on, DRVLOCK /off or EJECT utilities accept it (B:) as
a supported drive.
And, having thought about it ***there ain't no signal
lines to control this
on the floppy interface***. So, perhaps you should get
a microswitch and
patch that into the circuit, then mount the
microswitch somewhere devious.
Or, even sneakier, figure out if any of the drive
select 2/3 or motor enable
2/3 signals are actually passed through the ribbon but
not connected on the
floppy drive's PCB circuitry and use one as 'gating
control' signal for the
>The *electronic* eject drive
is like the
standard push button drive. SONY made both of
them. The EE drive
allows you to lock the floppy disk in the drive by
flipping the eject button
disable switch on the side of the drive. Unfortantly
the program to software
eject the disk via the OS is missing in action ...
DISKETTE.DGS diagnostics "overlay" tests the "security
features" of the electronic diskette drives when
possible. A bit of reverse engineering might reveal
what is needed for
recreation of these utilities. However, doesn't PC-DOS
v7/2000 have the DRVLOCK
and EJECT commands? More fodder for the dedicated
It has - but it fails
with the EE-FDD as far as I can tell. At least when
using it in a Lacuna. As far as I can tell they have
been intended for CD-ROMs and MODs. DRVLOCK
eject button and EJECT forces a media ject on them.
*That* is known to work
under PC-DOS 7.0 with a CD-ROM installed ... I use
EJECT recently on my last
From Ernst Fueloep
With OS/2 you can use
the security features for the enhanced 2.88 diskette
drive from the diskette icon in the
drives folder. Just press the right mouse button and
you will get options for "Lock disk", "Eject disk" and
the security switch on the diskette drive is set to 1.
You can find this switch on the right side of the
Lock Drive Disables the load-and-eject
drive will not eject a loaded diskette, nor will it
load a diskette. (Depending
on the characteristics of the drive, it may load the
diskette and immediately
try to eject it).
Note Allow 500 mS after an Eject Media
command before issuing
Lock Drive cmd.
Unlock Drive Enables the load-and-eject mechanism,
which allows diskettes
to be removed from and inserted into the selected
Eject Media Same as pressing the eject button on
the front of
the drive; it causes the drive to eject a diskette.
This command is ignored
if the drive is locked.
an enhanced command:
Set the value in the
data-rate-select bits (in the Data Rate Control
register) at the positive-going edge of the
-security cmd signal.
1. Select the drive and save
the state of
the data-rate-select bits.
2. Ensure that the System
Control Port C
is available (bit 7 will be 0).
3. Set the enhanced-command
bit to 0 (bit 0 of the System Control Port C).
4. Set the data-rate-select
bits to the desired command.
5. Set the enhanced-command
bit to 1.
6. Restore the
data-rate-select bits to the desired data rate.
NoteIf the drive is deselected before the
is reset to 1, the drive does not perform the command.
Command encoding of data rate
|DATA RATE SELECT 1 0
|Status register A
|Data rate control