For those who haven't been following my recent posts, I recently got a Compaq Portable I. It's been quite a bit more work to upkeep than the other vintage machines I own. However, some issues I've been having are completely my own damn fault.
One of the gems of this past night was trying to install a hard drive into the portable using one of my two remaining Hard drive controllers. After screwing up the twist of the MFM cable multiple times (this gets it's own thread!), I successfully got my drive (Tandon TM-502) recognized by my hard drive controller (Seagate ST11R)... only to get the good ol' "Drive Parameter Activity Failed (0x07)" in both the Seagate BIOS and SpeedStor formatter. Furthermore when this Tandon drive was paired with this controller, the actuator carriage assembly would never move at all when I finally got the twist in the cable correct. Then I attached a Seagate ST-4038 to this controller, and while formatting still failed, the hard drive would respond to park, seek, and even respond to a (botched) media analysis in SpeedStor which suggested all sectors were bad.
On my second RLL controller (WD 1002-27x), no matter which drive was attached, and regardless of the twist in the cable, a 1701 error was triggered. I believe this means controller failure, but I've seen this occur even when the controller is just fine (known to work). I can't help but wonder- is it possible that the WD 1002-27x was able to sense drive parameters and detect that an MFM drive was attached? And subsequently choked and died with 1701? I'll have to try again...
And why did the programmable Seagate drive fail when it supports 17 sectors per track? My only educated guess is based on something vwestlife said:
I'm thinking the latter is the case. Before tonight, I thought an MFM drive would tolerate an RLL format, but there was no guarantee data would be written reliably thereafter. My WD 1002-27x controller also supports 20MB MFM drives... I'll try that next.
Why such wildly varying behavior between drives (drive attempts seek vs drive doesn't respond), and controllers (1701 consistent on one controller)? Weren't both drives being sent the SAME commands barring the drive geometry parameters? And I don't know this for sure, but I thought the drive geometry was stored on disk during low level format... shouldn't have the Seagate controller detected this condition and choke with 1701 like the WD controller? Or is that 1780 and I'm confused.
And now that I've verified that the drives are actually functional in my PC/AT, I'm wondering- was the AT ever come stock with an RLL controller and BIOS support for it?
Sorry for all the questions people XD... I'll try to break it up better when I have a moment.
One of the gems of this past night was trying to install a hard drive into the portable using one of my two remaining Hard drive controllers. After screwing up the twist of the MFM cable multiple times (this gets it's own thread!), I successfully got my drive (Tandon TM-502) recognized by my hard drive controller (Seagate ST11R)... only to get the good ol' "Drive Parameter Activity Failed (0x07)" in both the Seagate BIOS and SpeedStor formatter. Furthermore when this Tandon drive was paired with this controller, the actuator carriage assembly would never move at all when I finally got the twist in the cable correct. Then I attached a Seagate ST-4038 to this controller, and while formatting still failed, the hard drive would respond to park, seek, and even respond to a (botched) media analysis in SpeedStor which suggested all sectors were bad.
On my second RLL controller (WD 1002-27x), no matter which drive was attached, and regardless of the twist in the cable, a 1701 error was triggered. I believe this means controller failure, but I've seen this occur even when the controller is just fine (known to work). I can't help but wonder- is it possible that the WD 1002-27x was able to sense drive parameters and detect that an MFM drive was attached? And subsequently choked and died with 1701? I'll have to try again...
And why did the programmable Seagate drive fail when it supports 17 sectors per track? My only educated guess is based on something vwestlife said:
MFM and RLL drives are mechanically identical. RLL drives were simply tested and certified by the manufacturer to meet a higher data reliability standard than MFM drives, because RLL squeezes 26 sectors per track onto the disk while MFM uses only 17 sectors per track, thus RLL increases the data density being stored on the magnetic surface of the platters.
The Seagate ST-11R controller card was designed for RLL, but you can tell it to format the drive with only 17 sectors per track. Whether that actually switches it into MFM mode, or if it's just only formatting the first 17 out of RLL's 26 sectors per track and leaving the rest blank, I have no idea. Maybe a program like SpinRite could do a surface scan of the disk and tell you how the sectors are laid out on the tracks.
I'm thinking the latter is the case. Before tonight, I thought an MFM drive would tolerate an RLL format, but there was no guarantee data would be written reliably thereafter. My WD 1002-27x controller also supports 20MB MFM drives... I'll try that next.
Why such wildly varying behavior between drives (drive attempts seek vs drive doesn't respond), and controllers (1701 consistent on one controller)? Weren't both drives being sent the SAME commands barring the drive geometry parameters? And I don't know this for sure, but I thought the drive geometry was stored on disk during low level format... shouldn't have the Seagate controller detected this condition and choke with 1701 like the WD controller? Or is that 1780 and I'm confused.
And now that I've verified that the drives are actually functional in my PC/AT, I'm wondering- was the AT ever come stock with an RLL controller and BIOS support for it?
Sorry for all the questions people XD... I'll try to break it up better when I have a moment.