@DDFF.ADF - IBM ESDI Fixed
90X8969 Marked 90X8971 internally
90X8970 Marked 90X8972 internally
04G3759 Update ESDI firmware
MFM Controller 72X8540
U30 is covered with a grey-black resilient compound
that has a heatsink? pushed into it?? The edgecards at
the top are not labelled. U4 and U7 have the metal
can/ceramic construction you love so much.
The ceramic shield has been obsolete on
the new redesigned MFM adapter for Mod. 60 & 80.
These adapters were already a "factory reworked" card -
first series cards had the U30 module without the
shield and experienced "sudden death" due to some
sensibility against electrostatic discharge. Therefore
the shield. The P/N for the various cards stayed
[Source: IBM Engineering Changes Group 819 - PC-Family / PS2 Family Service Information Manual, IBM Doc.No. SR28-0280-2 / 3rd Edition Nov. 1987]
Intel P8051AH (MCS 51 Family) Datasheet
AMD AM26LS31PC Datasheet
Charles Lasitter impudently asks
Any hope of substituting larger drives for this machine, and if so, what's the point at which it will freak out over translation issues and require exquisitely unique device drivers to step in front of the operating system and hide the messiness?
From Anarcho-Hacker Peter
Another significant difference: IBM has
castrated the 4-device ST-506 interface down to 2
devices with altering the device addressing a bit. All
drives have to be set to "second drive" (DS1 when
counting "0"-based from DS0 to DS3). The two possible
drives are addressed with the motor-on and drive select
lines - and a twisted cable for the first drive, which
"corrects" the false addressing logic. The IBM PS/2 BIOS
also and consequently supports only two MFM drives (and
two ESDI as well ... they repeated the mistake there
This part is still missing in the PS/2
Reference PDF section. I *think* I have the MFM
controller HITRM or TRM anywhere ... but I might be
wrong. I PDFed the ESDI and SCSI controllers - which
seemed the more important to me.
ESDI Hard Disk Attatchment
U25 appears to be the Even BIOS,
U13 the Odd BIOS
How Many Drives are Supported?
EPROM for ESDI Adapter/A
If U16 is 04G3759, then this ECA has already been applied. Modules with any other P/N should be replaced by using this ECA.
DOWN - level U16
15F6587 :caused a diagnostic formatting problem and an intermittent hardfile delay during system operation (the hardfile light would remains "on" for approx. 13 seconds). also, in rare instances, a write fault could result in a data shift problem during error recovery, which would be detected during read operations and during diagnostics as a "10473" error (ECC error; read error).
15F6807 : caused a highly intermittent problem of undetected write faults on the last 1/3 of the last sector written (detected during system read operations and by diagnostics as error code 10473, ECC read errors).
91F7430 : experienced a highly intermittent system "HANG" only on 115MB ESDI fixed disks.
If the user software fails after this module is changed, the original module should be re - installed, and the appropriate software support function should be contacted for any possible software patches or updates.
Installing a Second ESDI Drive
From Joe Kovacs
You will need another data-cable for the new drive. The wide control cable has a second plug already. To make it a D: drive, you take out the resistor (Or some models use a DIP switch).
Run automatic configuration, low level format it (CTRL-A on the main menu), fdisk it, DOS high level format it, and you're away.
As I understand it, the ESDI drives for the 80-class machines had identity data stored on the drive itself. If it's not an original equipment ESDI drive, or if it *IS* an IBM drive but has since been low-levelled in another (non-IBM) machine, it can't be put back in an 80 unless the Reference Diskette is "cooked". For Peter Wendt's recipe, look HERE.
8560/8580 Harddisk Wiring
Cable from J1 to HDs #2 and #1
is twisted for 5 lines 6 to 10 between HD#2 and
"How to build your own ESDI terminator"
12 11 10 ... 3 2 1 = Pin No.
Pins 12 - 2 are 150 Ohms against Pin 1
(C) 1999 by Peter H. Wendt
Cables from RadioSchlock Dated, for
Maxtor 8760E ESDI drive problems on IBM ESDI controller
What could be causing so many 10480s (seek errors)- The drive light flickers on the disk, but is constant on the top hd light, and only gives 10480, even though it looks like it works. The drive was pulled from a 486, what could be wrong with the drive/controller in the model 80? I've read a post about setting a 380MB and other nearly alike ESDI drives similar to mine, but none of the tips work/apply so far. I've even tried custom cables, and different types of 34pin cables. What do I need to do to either get ibm's cable for this card(number please?)
ESDI in a 9577 Bermuda?
From Werner Förtsch
I have a 9577 with an onboard SCSI with one hd drive which was up to now my boot disk. I found from an old PS/2-80 an ESDI controller and two ESDI drives which I istalled in the 9577. After long I got the system up running. My problem now is that my 9577 now boots from the first ESDI drive. Is there any possibility to boot from the SCSI harddrive in changing something in the firmware?
>Thank you anyway for your helpful
So if you just tried it for
curiosity - you better leave it. I tried something
similar back in 1989 with the Mod. 80-311 to add an SCSI
adapter for larger drives and wanted to boot from the
SCSI ... did not work. The ESDI always started first.
This misbehaviour is (as far as I know) buried in the
different handling of ESDI and SCSI from the BIOS.
If anyone else finds a way - okay - I am interested. But as far as I know - and from my own experimenting - it does not work. (Also: Mod. 70 with IBM SCSI and SCSI-HD: also starts from the DBA-2 ESDI drive first)
(Ed. Peter points out the 16 bit compatibility mode the SCSI and ESDI controllers create. So you can run W95 with this setup, but...)
>You are right it will be much better to invest some
money for a new SCSI drive.
Is the IBM Integrated HD Adapter an ESDI Controller?
First off: The "IBM integrated harddisk adapter" (Card-ID DF9F) as it can be found in 50Z, 55SX, 70 and P70 is not a real ESDI drive. It is more or less technically an MFM RLL 2.7 drive - but combined with a MCA harddisk adapter in one physical unit. The "ESDI or not misunderstandment" is caused by the PS/2 BIOS.
They (IBM) treated the drive as ESDI, because back in those days the MFM harddisk standard was limited to 17 sectors per track (and still is for pure Non-RLL MFM drives) and while the "modern drives" used to be smaller and use lesser platters and -therefore- lesser heads it was easier to translate the physical geometry with e.g. 929 cylinders, 56 sectors and 4 heads into a scheme with 64 heads, 32 sectors and "downscale" the number of cylinders accordingly.
The above example (929 x 56 x 4) would result in 208.096 data blocks á 512 bytes = 106.545.152 bytes. The translation into the 64/32 ESDI scheme would result in the more handy 101 cylinders ... by cutting down the total capacity to 105.906.176 bytes total. However the values 101 cylinders, 64 heads and 32 sectors give a better match into the old XT/AT controller scheme - particularly the cylinder register was -according to the basic WD1007 controller- the problem. It could not hold values over 1.024 ... the ESDI translation in the BIOS opened a more handy way to handle bigger drives up to 1GB IIRC.
So after all the "ESDI" in the desktops using the integrated harddisk thingy is only imaginary. The towers (60 and 80) used "Real" ESDI controllers and harddisks.
Secondly the DF9F HD / controller combo was primarily designed as "single device". The later @DF9F.ADF allowed to set one as "primary" and one as "secondary". But as far as I know this has been included to match an early draft of the PS/2 Mod. 90 hardware .... which *had* two integrated harddisk controller ports at the front end of the sysboard. These however had been made non-functional in the later platform BIOSes and don't work. I have played around with them in the early 90s but found no clue to get them working with any Type 1 - 3 platform. As well as Alfred Arnold tried recently - don't know if he gave up yet.
I hadn't been that desperate to try installing the 386DX-20 (Type-0) platform in my 8590 and see if I get the front drivebays going with that.
Due to the lack of appropriate connectors none of the PS/2 machines support two integrated harddisk adapters. These *are* MCA connectors. The 72-pin layout of these drives is basically a slightly stripped-down 16-bit MCA connector. And the planar ADF for e.g. a Mod. 55SX says "4 slots" where the Slots 1 - 3 are for expansion cards and Slot 4 is at the end of the riser card - extended with a flat-ribbon cable over and down to the harddisk.
And - No - you cannot just crimp another 72-pin connector in that cable. There are signals that select the slot number - and that for this "cable port" is fixed set to Slot 4 ... so any other connector on that cable would signal "Slot 4" to the sysboard. It is -as said- "stripped down" ... means: apart from some DC- and GND-wires also "other unimportant signals" are not passed over to the HD-connector.