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Plus Hardcard BIOS

ST251

ST251

Experienced Member
Joined
Oct 19, 2020
Messages
146
Location
Northeastern US
I've been tinkering with Plus Hardcards (most of them are dead for various reasons) and I have a few that will read some tracks but not all. That got me thinking that it was MFM style magnetic field degradation (the style that's fixed with a low level format).

Now most of the cards I have don't allow low level formatting, booting you out the program to a *Fixed Disk BIOS Error* screen but then I encountered one that actually let me low level format it. I'm just wondering what routine did they patch out in the later BIOSes and would it be possible to undo their changes? The biggest complication is that the card that lets you low level format it is a Hardcard 20 and I want to recover a Hardcard 40.
 
I found the switch settings in a FCC archived document. Looking at old posts it seems to be hard to find which I put under
Pictures of the boards and firmware dumps would be nice to archive. I picked up a 42 recently, but that is a normal ide drive and controller
rather than the integrated non-ide designs of the earlier cards.

also two patents 4639863 4819153
 
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Descriptions of the Hardcard track formats are in the patents.
They have embedded servo information. I wonder if something is broken in their firmware and it erases the servo information
if you try to low-level format the bigger disks.

I found some pictures of the 40 meg hardcard, which I added to bitsavers. It appears to have variable bitrate recording (there are
two crystals on the data separator) so it doesn't have a constant CHS
 
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Ruud said:
Have a look at SpeedStor. In the 80's it was a great help for me.
Click to expand...
That's what I was using and that's the program that let me format that one Hardcard. It's a great program.
Al Kossow said:
I found the switch settings in a FCC archived document. Looking at old posts it seems to be hard to find which I put under
Pictures of the boards and firmware dumps would be nice to archive. I picked up a 42 recently, but that is a normal ide drive and controller
rather than the integrated non-ide designs of the earlier cards.

also two patents 4639863 4819153
Click to expand...
I can get photos and BIOS dumps up here sometime within the next week. I will admit, some of the boards might no longer be identifiable to me on account of the actual hard drive assembly being missing.
Al Kossow said:
Descriptions of the Hardcard track formats are in the patents.
They have embedded servo information. I wonder if something is broken in their firmware and it erases the servo information
if you try to low-level format the bigger disks.

I found some pictures of the 40 meg hardcard, which I added to bitsavers. It appears to have variable bitrate recording (there are
two crystals on the data separator) so it doesn't have a constant CHS
Click to expand...
The drive that let me format it did slow down a bit so I wonder if there's some fallback mode that allows it to operate without the servo information. I can't test that drive any further as it suffered a head crash (which may or may not have been caused by the particular disk assembly being made up of platters from two different Hardcards :ROFLMAO:)
 
Just an update, I got that drive to work long enough to verify that I wasn't imagining that, and I wasn't. This photo is SpeedStor performing a LLF on that drive and to follow shortly will be the data from the 2764 and 27128 EPROMs

IMG_20231022_024228b.jpg
 
I did a little more testing earlier today. Swapping the 2764s from one drive to another allowed SpeedStor's write tests to function but attempting a low level format resulted in a "Bad command to disk BIOS" message (and it also made the drive ID as 10MB but manually entering the parameters into SpeedStor allowed it to access all the cylinders).
 
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jafir said:
@Al Kossow, Here are some photos of mine and the ROM dumps. One of my ROM is identical to the ones from ST251, but the other is different. @ST251 do your ROMs have numbers written on them?

www.dropbox.com

hardcard20.zip

Shared with Dropbox
www.dropbox.com www.dropbox.com

Also, someone else has some dumps of one of the ROM and the utility disk image here: https://ibm-pc.org/firmware/other/plus hardcard/plus hardcard.htm
Click to expand...
Those two images appear to be the same as the one I uploaded.

Yep, they're labelled and I'm listing them below.

B33 and F34
B42 and F34
B58 and F73
B58 and F74
B61 and F74
B62 and F74

I have one more but it's in a closed computer.
 
Just to clarify, I mean the two images on ibm-pc.org - I didn't catch my mistake before the post edit period passed.
 
Hello all
I just found this topic here since I recently got the same card, a Plus hardcard 20 from someone.
Putting it into a AT with the corresponding jumper setting just leads to a hanging POST with the message 1701 - controller #0 error.

The drive is spinning and initializing its heads but apart of this its just dead.

May I ask why these hard drives are used to be dead now? Is there something to bring them back to live?
I'll try to read out the ROM content later on to make sure that it's data didn't vanish over the years.

Thanks in advance
Dallas
 
There are some videos on YouTube showing the problem. There is a rubber bumper inside that the head assembly rests against and the rubber turns sticky and the heads stick to it.
 
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