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WD1002A-WX1 + Seagate ST-251 Configuration on IBM 5150

nullvalue

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I decided to start a new thread for this topic, which started here.

I am installing a Seagate ST-251 into an IBM 5150 which has an upgraded PSU and the latest BIOS. I do not know what BIOS is on the WD1002A controller card.

I got into the configuration using (debug, g=c800:5) and it first asks about Interleave (I left the default of 3). I said yes to dynamic configuration and entered "820 6 821 821 11 3" - then asks if I want to configure virtually? I chose N. It then begins formatting and immediately throws an "Error---completion code 80".

Does my cabling look correct? The edge connectors at the hard drive only go one way. However, I wasn't certain for the orientation on the controller board header. Also, do I need to consider anything else like termination? Or which edge connector position I use on the cable?
20210211_111837.jpg
 
This first drive is an ST-251-1, I just tried with my other drive which is marked ST-251 MLC-0. This drive is jumpered differently and has no resistor pack installed on the bottom like the ST-251-1 does. Issued the same commands and this one is formatting! I also was getting a boot code "1701" with the other drive, but this one didn't throw that message.
 
When formatting finished (took maybe 10 minutes) it asked if I wanted to format bad sectors? I just chose N. Issued a FDISK and created the primary partition - after rebooted, I formatted C: (took about another 10 minutes) and I have 33MB available! (about 10k bytes in bad sectors - is this normal?) Then I issued the SYS C: command and copied the contents of my 2 PC-DOS 3.30 floppies to the C:\. Rebooted without a floppy and to my utter surprise it booted from C: no problem! I'll see if I can get that other drive formatted. Thanks for your help!
 
Thanks! If I upgrade to 3.31 how much more space could I get out of an ST-251? Also do you have a 360kb version of 3.31? WinWorld has MS-DOS 3.31 but only in 1.2MB.. I could split it if necessary. Was there a PC-DOS 3.31?
 
I believe it’s approximately 42mb. The other option would be to keep your current version and just add a second partition with fdisk and format that.

I’ve got compaq dos 3.31 on 720k 3.5” floppies. I’ve also got MS-DOS 6.22 on 5 1/4”. I think both of those are on winworld.
 
There's also the Disk Manager route. If memory serves Phil's computer lab website has a copy for download.

Winworldpc only has Compaq MS-DOS 3.31 on 360k in German. They have English versions in 720k images. One could always plug a 1.44 drive into the system long enough to install from 720k floppies.
 
Ok so using a different computer with both a 5.25 and a 3.5 drive I made a 1.44mb MS-DOS 3.31 boot disk. From that I was able to format/sys the 5.25" 360kb disk. So after all that I was able to boot to 3.31 from the 5.25" floppy and it formatted the ST-252 to a whopping 42MB! Thanks guys..
 
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Nullvalue, cograts that's a nice controller and drive combo! A few bad sectors are perfectly normal on drives of this vintage, no worries with that. How does it sound? They're pretty loud, but hopefully the spindle bearing sounds relatively nice. ST-251 is auto-park as well. Cheers!
 
Love the sounds these old MFM drives make - it's actually not that loud - bearings sound clean. However I do have a problem. Yesterday evening I turned the machine back on and noticed the hard drive didn't spin up. Turned it off & back on and it came on. This morning I power it up and nothing on the hard disk. It's possible I really don't have the upgraded power supply?
 
Try wiggling the power connector to make sure of good contact.

Also with the ST251, board failure is a common problem, which the symptom is that the drive stops spinning. There's a chip on the board that sometimes fails to drive the motor. Doubt it's the power supply, but you can always take a voltage measurement to be sure. You could also possibly remove the control board and try wiggling the gray ribbon cable that connects to the spindle motor.

I made a video yesterday for another member to see how to swap the control board ... if you want to try the spindle motor cable, you can see it in the video: https://youtu.be/6laAja8zPUo (sorry about the CGA monitor whine at the start of the video, the camera picked it up ;)
 
Try wiggling the power connector to make sure of good contact.

Also with the ST251, board failure is a common problem, which the symptom is that the drive stops spinning. There's a chip on the board that sometimes fails to drive the motor. Doubt it's the power supply, but you can always take a voltage measurement to be sure. You could also possibly remove the control board and try wiggling the gray ribbon cable that connects to the spindle motor.

I made a video yesterday for another member to see how to swap the control board ... if you want to try the spindle motor cable, you can see it in the video: https://youtu.be/6laAja8zPUo (sorry about the CGA monitor whine at the start of the video, the camera picked it up ;)

Which chip? I had an ST-251 doing exactly that
 
I have two ST-251's and the second one isn't spinning either now, which led me to believe it could be more of a PSU issue..
 
DSC03412_01.jpgDSC03412_03.jpg

See the discolored chip in the pics? It's the smaller chip just below center of pic. This is the one that I've observed to fail.

Also, from my previous post, I incorrectly identified the spindle cable as the gray ribbon ... the spindle motor is indeed the one toward the middle of the drive (the first one I unplug in the video). If you try wiggling that connector, it might resolve any issues with poor contact between connector and pins.
 
nullvalue, interesting! You can try powering the drive all by itself and that shouldn't overload the power supply. Take a voltage measurement if you can just to be sure the voltages are there ... 12v still outputting?
 
View attachment 66465View attachment 66466

See the discolored chip in the pics? It's the smaller chip just below center of pic. This is the one that I've observed to fail.

Also, from my previous post, I incorrectly identified the spindle cable as the gray ribbon ... the spindle motor is indeed the one toward the middle of the drive (the first one I unplug in the video). If you try wiggling that connector, it might resolve any issues with poor contact between connector and pins.

Sadly a brief search seems to indicate this part being difficult or impossible to source
 
That's ultimately the issue ... the chips aren't available ;) Maybe from a donor board if the failure was a different chip, but yeah if we could identify that chip then fixing it might be possible.
 
nullvalue, interesting! You can try powering the drive all by itself and that shouldn't overload the power supply. Take a voltage measurement if you can just to be sure the voltages are there ... 12v still outputting?

Definitely not. Just took a measurement at the 4 pin Molex and nothing! I hear the PSU fan come on but nothing else (no screen, beep or drive activity)..
 
Power supply might be bad or there is a short which is preventing it from turning on. The fan will spin, but that's about all you'll get ;) If you unplug the power supply from everything, try one device at a time, like your hard drive or then a floppy drive... just need to get a small load on the power supply for it to start up. That would rule out whether there is a short on the drive board (or elsewhere) which is causing the power supply to not start.
 
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