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huubwen
July 14th, 2012, 06:40 AM
My new project is to add a hard disk to my original diskless IBM XT (5160).

I bought an old clone with a DATA TECHNOLOGY DTC5150BX MFM controller and a Seagate ST-225 hard disk. I don’t know any about the history of this clone. The clone did not start from the disk before I took out the controller and disk.

I found the dip switch settings for the DTC5150BX on http://www.t-zero.org/archive/old_jumpers_pinouts/c/txt/20060.txt
The settings of the ST-225 do not exactly match (http://stason.org/TULARC/pc/hard-drives-hdd/seagate/ST225-21MB-5-25-HH-MFM-ST412.html) with the available options on the DTC5150BX.

I have tried several DIP switch setting. With the 15MB/6/306/256 and the 22MB/4/640/256 the controller detects the hard disk and displays after the memory count “1 harddisk detected”.
With both settings I low-level formatted the disk. (debug C800:0005) The utility displays that the disk format was successfully after about 1 minute.

I cannot get past fdisk :(
DOS 3.3 fdisk displays: “Error reading fixed disk”
FreeDOS fdisk displays: “Invalid drive designation…Operation Terminated”

What could be the problem?

Stone
July 14th, 2012, 07:06 AM
I've never seen an XT that could LLF an ST-225 in a minute. I'm guessing that whatever you did the disk still needs a LLF.

Chuck(G)
July 14th, 2012, 09:31 AM
I don't know if it will matter, but there were several revisions of the firmware. Which one do you have? (I still have the manual for the controller).

huubwen
July 14th, 2012, 10:00 AM
Well I made some progress. I figured out that allmost all DIP switch settings will result in an successful low level format. But not all formats work with fdisk.

I figured out that 20MB/8/306/0 does not work. Fdisk error reading fixed disk.

The settings for 22MB/4/640/256 works but when DOS format reaches about 97% the drive is suddenly seeking wildly. It keeps doing this and format does not progress anymore. Perhaps because the low level formats extends the physical drive space? I aborted format and did a quick format. This works only the performance is poor.

The setting 18MB/4/512/256 looks like the optimum. No errors and no bad sectors and the performance is as expected from a ST-225. Only wasted 2MB.

And yes, the XT did the low level format on all settings between 1 and 2 minutes.

I have no idea about the firmware version. The low level format utility says v1.1.

Any advice about better settings for the ST-225?

Stone
July 14th, 2012, 10:18 AM
21 MB
615 cyllinders
4 heads
17 sectors/track
512 bytes/sector

huubwen
July 14th, 2012, 10:26 AM
Thanks, but unfortunately my DTC5150BX controller does not support these optimum settings.

ahm
July 14th, 2012, 10:59 AM
I believe the DTC-5150-BX controller was used in the AT&T PC-6300.

According to my notes, the DIP switch settings for the 20MB Seagate ST255 should be:
1 2 3 4 5 6 7 8
1 0 1 0 0 1 0 1

Chuck(G)
July 14th, 2012, 01:30 PM
Again, the version of the BIOS matters. You can usually get a clue by looking at C800:0 and following using DEBUG. You should see a text string with the version number.

My DTC5150BX manual is for the BXD6 BIOS. This is the BIOS that allows for "splitting" a large drive into two virtual smaller ones (DOS 2.0 could handle only 16MB per drive). For your ST225 (615/4/17), there are no switch settings that allow you to use the entire drive, but you can use the first 612 cylinders by setting the switches as follows:



Switch
12345678
-----------
10101111

where 1 = on, 0 = off

Note again, that this is for the BXD6 BIOS. Other 5150BX versions will be different.

modem7
July 14th, 2012, 02:50 PM
Any advice about better settings for the ST-225?
As Chuck wrote, we really need to know which BIOS you have, BXD05 or BXD06. It is usually printed in large letters on one of the chips (the BIOS chip). Example at http://www.minuszerodegrees.net/rom/dtc_5150cx.jpg

Replacement EPROM

A few of us on these forums have the ability to modify the BIOS to support a particular drive type. I've done it myself on a BXD06 BIOS to support an ST-506. The modified BIOS is burnt into an EPROM, of type 2764. That EPROM chip is posted to you and you use it to replace the existing BIOS chip.

I can produce the image (at no cost) for the EPROM, and perhaps someone in Europe can burn that image to a 2764 EPROM and then post the EPROM to you (for possibly small cost).

huubwen
July 15th, 2012, 12:49 AM
I have used debug and dumped after C800:0000. This was some of the output:

-d c800:0

C800:0000 55 AA 10 EB 1D E9 56 08-5B 42 58 44 2D 30 35 20 U.....V.[BXD-05
C800:0010 28 63 29 20 44 54 43 20-30 36 2D 41 70 72 2D 38 (c) DTC 06-Apr-8
C800:0020 34 5D B8 40 00 8E D8 B8-00 00 8E C0 FA 26 C7 06 4].@.........&..
C800:0030 34 00 4D 08 26 8C 0E 36-00 26 A1 4C 00 26 A3 00 4.M.&..6.&.L.&..
C800:0040 01 26 A1 4E 00 26 A3 02-01 26 C7 06 4C 00 28 03 .&.N.&...&..L.(.
C800:0050 26 8C 0E 4E 00 26 C7 06-64 00 AF 01 26 8C 0E 66 &..N.&..d...&..f
C800:0060 00 26 C7 06 04 01 1D 02-26 8C 0E 06 01 FB C6 06 .&......&.......
C800:0070 74 00 00 C6 06 75 00 01-B9 0A 00 8A 16 75 00 D0 t....u.......u..
-d

C800:0080 E2 80 E2 FC 88 16 77 00-E8 3E 07 B6 00 8A 16 75 ......w..>.....u
C800:0090 00 FE CA 80 CA 80 B4 12-CD 13 72 5D B4 14 CD 13 ..........r]....
C800:00A0 72 57 C7 06 6C 00 00 00-81 3E 72 00 34 12 75 06 rW..l....>r.4.u.
C800:00B0 C7 06 6C 00 32 01 FA E4-21 24 FE E6 21 FB B4 09 ..l.2...!$..!...
C800:00C0 CD 13 72 43 B4 10 CD 13-73 0B 81 3E 6C 00 68 01 ..rC....s..>l.h.
C800:00D0 72 F2 EB 25 90 B4 11 CD-13 72 2C 8C C8 8E C0 BB r..%.....r,.....
C800:00E0 00 00 B4 0F B0 01 CD 13-72 1D FE 06 75 00 FE C2 ........r...u...
C800:00F0 F6 06 75 00 01 74 B9 EB-82 FE 0E 75 00 80 3E 75 ..u..t.....u..>u
-d

C800:0100 00 01 73 1A EB 05 90 FE-0E 75 00 BD 0F 00 B9 05 ..s......u......
C800:0110 00 90 BB 3D 01 E8 37 00-E8 65 00 E8 4A 00 A0 75 ...=..7..e..J..u
C800:0120 00 E8 4E 00 B9 0B 00 90-80 3E 75 00 01 75 01 49 ..N......>u..u.I
C800:0130 BB 42 01 E8 19 00 E8 2F-00 E8 D5 06 CB 31 37 30 .B...../.....170
C800:0140 31 20 20 48 61 72 64 20-44 69 73 6B 73 0D 0A 56 1 Hard Disks..V
C800:0150 BE 00 00 2E 8A 00 E8 05-00 46 E2 F7 5E C3 53 B4 .........F..^.S.
C800:0160 0E BB 00 00 CD 10 5B C3-BB 4D 01 B9 02 00 E8 DE ......[..M......
C800:0170 FF C3 24 0F 3C 09 76 02-04 07 04 30 E8 DF FF C3 ..$.<.v....0....

There was no further readable output except for the strings displayed by the low level format utility.
Does this mean the BIOS version is 05?

modem7
July 16th, 2012, 12:05 AM
Does this mean the BIOS version is 05?
Yes. It is the BXD05 version of the BIOS.

Your 5150BX card can also use the BXD06 version of the BIOS. I know because a friend has the BXD06 BIOS in his 5150BX.

The drive entries in the BXD06 BIOS are shown [here] (http://stason.org/TULARC/pc/hard-disk-floppy-controllers/C-D/DATA-TECHNOLOGY-CORPORATION-Two-MFM-ST506-412-driv-186.html).
Entry #2 (612 cyls, 4 heads) is a close match to the ST-225 (615 cyls, 4 heads).

An image of the BXD06 BIOS is at http://www.minuszerodegrees.net/rom/rom.htm
Someone can use that image to burn a replacement BIOS chip for you.