Trying to FDISK a 20meg HD?

[jodyspencer]

Hello .. I have a NEC D5126 HD that my IBM 5160 with a XEBEC MFM controller would not recognize under FDISK,, so I did a low level format .. then it was recognized with FDISK. but using FDISK it takes forever then it says no room for partition ... ?

I used: Debug- enter

-a 100
mov ax,705
mov cx,1
mov dx,80
int 13
int3

g=100

took about 10-15min

Then I do

Fdisk /mbr

Then fdisk

It ask me create a dos partition (1)

which I do

but it never asked my what size
it just starts the fdisk which takes 2 hrs then says no room for a dos partition
Any help would be appreciated ... Mike

 

[Stone]

Which Xebec do you have?

Some of them won't support a 20MB drive.

 

[jodyspencer]

I believe its called the 20MB Fixed Disk Drive Adapter has the Xebec Rom,, number on front of controller 62X0786 number on back 62X0776 I have jumpers set off/on/off/on.. I have interleave set mov ax,705 is that correct or does that matter? I am new at this.. Mike

 

[modem7]

I have a NEC D5126 HD that my IBM 5160 with a XEBEC MFM controller

I believe its called the 20MB Fixed Disk Drive Adapter has the Xebec Rom,, number on front of controller 62X0786 number on back 62X0776 I have jumpers set off/on/off/on..

In my opinion, that is valid.

I used: Debug- enter

-a 100
mov ax,705
mov cx,1
mov dx,80
int 13
int3

g=100

So you are following the instructions at [here]

took about 10-15min

With that controller, in a 5160, a low-level format (LLF) of a 20 MB drive normally takes between 2 and 5 minutes. 10 to 15 minutes is not normal. During the LLF, you should see the steppper arm [photo], slowly moving, from one extreme to the other. If it sometimes pauses, or sometimes moves back to track 0, then there is a problem. You may see the arm return to track 0 at the end of the LLF.

Then I do
Fdisk /mbr

Not required. Omit that just in case it is causing a problem.

Then fdisk
It ask me create a dos partition (1)
which I do
but it never asked my what size ...

I presume that you are writing of step 1.5 at [here].

... it just starts the fdisk which takes 2 hrs then says no room for a dos partition

In the IBM/Xebec LLF instructions that I pointed to earlier, there is a 'Step 2 - Zero data in first sector' section.
Did you do that step (after the LLF, but before DEBUG)?

 

[jodyspencer]

Yes I followed both steps in order.. After re-reading the info on that page I started wondering If maybe that 1st step is for a ST412 only that maybe I need to change the mov dx,80 to another value... as I LLF, fdisked, and formatted a ST412 with no problems..

 

[Stone]

Try SpeedStor. It will format the drive and run a set of controller diagnostics, as well. It's possible that the controller has a problem.

 

[modem7]

Yes I followed both steps in order.. After re-reading the info on that page I started wondering If maybe that 1st step is for a ST412 only

The IBM BIOS on an IBM 5160 motherboard does not 'know' about hard drives; the hard drive 'intelligence' being in the XT-class hard drive controller.
When you executed step 1 of the subject procedure, code in the BIOS chip on the controller got run.
For variation #3 of the IBM/Xebec card, that code will read the card's switch settings and act accordingly.

You had the "jumpers set off/on/off/on" which equates to a drive of 615 cylinders and 4 heads - matching the D5126 (615 x 4 x 17 SPT x 512 bytes = approx. 20 MB)

that maybe I need to change the mov dx,80 to another value...

80 = hard drive 0
81 = hard drive 1

81 is normally only used when you have a dual-drive configuration, and you want to LLF the second drive.

as I LLF, fdisked, and formatted a ST412 with no problems..

Of course, there is the possibility that the D5126 is faulty. It took quite a long time to LLF.
How long did the ST-412 take to LLF?
using the same controller, I would expect the D5126 to LLF in twice the time of the ST-412 (same head count, but twice as many tracks to step through).

 

[jodyspencer]

The 412 formatted pretty fast it was just a little while to LLF,fdisk and Format C: /s .. but anyway the Nec D5126 went snap crackle, pop and the Xebec controller will not Recognize it at all now.. so I guess it was bad after all. I guess I was beating a dead horse...

Mike

 

[Stone]

.. so I guess it was bad after all. I guess I was beating a dead horse...

Dead horse... that's just another name for an MFM drive.