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IBM 5162, Seagate ST-251-1, GSETUP, and a dead CMOS battery.....

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Exceter

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I have an IBM 5162 with a Seagate ST-251-1 drive in it. Unfortunately, the CMOS battery died and I've lost the hard drive settings. There's no drive type sticker on the hard drive that I can see. I've googled the drive and it's supposedly a type 3, 40, or 44 here and here. Neither 40 or 44 are a valid selection in either the original diagnostics disk or in gsetup. Option 3 is available in gsetup but it doesn't work. What should I do?
 
From the Internet: Seagate ST-251-1 = 820 cylinders / 6 heads / 17 sectors per track

At [here], a web page that covers the subject matter, there is no exact match for 820/6/17. You (or a previous owner) must have used a type number where either:
* Match on cylinder count, but head count less than what the drive has; or
* Match on head count, but cylinder count less than what the drive has; or
* Both cylinder count and head count less than what the drive has.

All three of the above options result in reduced drive capacity being used.
Example: Use of IBM type 3 would result in 75% (615/820) of the drive being used.
Example: Use of IBM type 10 would result in 50% (3/6) of the drive being used.
Example: Use of IBM type 8 would result in about 75% of the drive being used.

However, maybe drive overlay software had been used to gain full capacity.

Exceter said:
Option 3 is available in gsetup but it doesn't work.
Click to expand...
What symptoms?

How about you set IBM type 8 and see if the drive boots and executes things okay.
 
modem7 said:
What symptoms?

How about you set IBM type 8 and see if the drive boots and executes things okay.
Click to expand...

"Non-system disk or disk error" for types 3, 8, and 10. I've never actually seen this computer boot before so it's possible that it either doesn't have an operating system installed or that the drive is non-functional(although it sounds fine). How would I attempt formatting the drive as type 8?
 
I could be wrong here, but if I remember correctly the "Non-System disk or disk error" is actually from MS DOS for media that hasn't been made bootable, which would indicate it's working but doesn't have MS DOS installed. Usually if a disk isn't working you get thinks like "insert system disk and press any key" or "boot error" or "no rom basic" or end up in BASIC (on IBM) .

If I'm wrong, someone please correct me, but that was my understanding at least.
 
Yes, that's correct. It's the message you get when the disk was formatted but no OS installed.
 
Exceter said:
Shouldn't I only get that message with 1 of the 3 types not all 3?
Click to expand...

It probably only needs to read a sector or two right at the start of the media.
Edit: actually it'd just be the boot sector, and all of those formats will have Track 0 Head 0 Sector 0.
 
Did you try setting it to type 3 and then booting DOS from floppy to see if you can access C: ?
 
Exceter said:
I did with all 3 types. I got an error with 3 and 10 and an empty directory with 8.
Click to expand...
Then type 10 was used. Empty directory means it can read the FAT, which will only work when CHS addressing matches the format used.

If it is empty anyway, set it to type 3 and re-create the partition. This will give you more storage space.

However, maybe it was set to type 10 because of media defects.
 
set it to type 3 and then use some assembly code in DOS to change the cylinder count to 820 after boot

https://www.pcorner.com/list/HDUTIL/CHGTYPE.ZIP/INFO/

Here's the code modified with the correct settings for a ST-251
Code: 
Title CHGTYPE
page 55,132

cseg segment
org 2ch
envir label word

org 100h
assume cs:cseg, ds:cseg
start: jmp short begin

table dw 820 ; cylinders
db 6 ; heads
dw 0 ; not used
dw -1 ; precomp
db 0 ; not used
db 0 ; control byte bit 3 = more than 8 heads, bits 6 or 7 disable retries
db 0 ; 3 timeout bytes
db 0
db 0
dw 820 ; landing zone
db 17 ; sectors/track
db 0 ; reserved

; First we will move the new drive table to the environment space to
; save a few bytes of memory

begin: mov ax,envir ; get the environment segment
mov es,ax ; to es
mov di,0 ; start of environment space
mov si,offset table ; point di to table
mov cx,16 ; move 16 bytes
rep movsb ; transfer table to environment space

; Then point the INT 41H vector to the new table

mov ax,2546h ; point the INT 46H vector to new drive table for second fixed disk
mov dx,0
push ds
push es
pop ds
int 21h
pop ds

; And do a Terminate and Stay Resident saving nothing but the environment

mov dx,0 ; terminate and stay resident
int 27h
cseg ends
end start
 
That's scary looking. Is there any chance of that program doing something that cannot be reversed by unplugging the BIOS battery? Which assembler would I use to assemble it?
 
Exceter said:
That's scary looking. Is there any chance of that program doing something that cannot be reversed by unplugging the BIOS battery? Which assembler would I use to assemble it?
Click to expand...

lol what? it doesn't touch the CMOS data at all

I can send you a binary if you like, or you can build it with MASM. Are you using the ST-251 as a boot drive or as drive D?
 
maxtherabbit said:
lol what? it doesn't touch the CMOS data at all

I can send you a binary if you like, or you can build it with MASM. Are you using the ST-251 as a boot drive or as drive D?
Click to expand...

Sorry, I'm an assembly noob. lol The ST-251-1 is the boot drive.
 
Exceter said:
Sorry, I'm an assembly noob. lol The ST-251-1 is the boot drive.
Click to expand...

so because you're booting off the 251 that complicates things a bit

the best way to handle it IMO is to pick type 3 in the setup utility, then FDISK/format the drive - this will give you 75% of your capacity as drive C

then load the CHGTYPE program in your AUTOEXEC.BAT - this will alter DOS's perception of the cylinder count after boot up - after which run FDISK again and create a second partition in the unused space, then format said partition

you will have to load CHGTYPE at every boot (it's a TSR that takes up about 1kB) to gain access to the secondary partition

the tricky part is making sure the entire drive (all 820 cyls) gets low level formatted first before you try to high level format the second partition - I recommend booting from a floppy and using speedstor and manually overloading the geometry
 
I think I misunderstood you. The ST-251-1 is drive C but it's not currently bootable. I'm only able to boot from floppies at this point.
 
Exceter said:
I think I misunderstood you. The ST-251-1 is drive C but it's not currently bootable. I'm only able to boot from floppies at this point.
Click to expand...

no we're on the same page

first you boot from a DOS floppy and LLF the drive using speedstor with manual override for 820 cylinders

then partition/format the 251 normally as type 3, then install DOS on the hard disk, etc.
 
maxtherabbit said:
no we're on the same page

first you boot from a DOS floppy and LLF the drive using speedstor with manual override for 820 cylinders

then partition/format the 251 normally as type 3, then install DOS on the hard disk, etc.
Click to expand...

I have Spinrite running at the moment. It says it has 162 hours remaining... lol
 
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