On Tue, Feb 2, 2010 at 4:23 PM, Daniel Malament <[email protected]> wrote: >> holy cow. >> of all the times NOT to post a dmesg! (and fdisk output). It >> probably wouldn't help diagnose the problem, but it would be cool to >> see. :) Obviously, you got a PIII machine with ISA slots, not the >> most common of beasts (though they certainly exist). (actually, the >> dmesg would probably just show "wdc0 at ... ", but it would be kinda >> cool to know that it was REALLY a wdc, not a low-end IDE interface >> pretending it was an AT controller). > > Heh. It does. I'll have to remember to save copies when I finally get all > this working. :) > > And the machine is a Dell Dimension with one PCI/ISA shared slot. > >> I think you need to go back to a P1 (or maybe some PII?) system before >> you will find one with manual drive parameter selections. That will >> lead to another problem, very, very very few of those will allow you >> to directly boot from the secondary controller. HOWEVER, you may be >> able to set the primary controller to the IDE, and put your MFM >> controller as secondary (many of the original ones had such a jumper) >> and be set, or install a SCSI controller and drive and use a boot >> floppy to boot from hd1a:/bsd... > > Yeah, I found it rather odd that it would do that in the first place. I > think what's happening is the BIOS can tell there's a controller there, but > then it doesn't recognize the drive as something bootable, so it goes to the > next hd. The 90 MHz Pentium I tried was, well, highly bizarre. For > example, the IDE jumpers were labeled 'PCI IDE' and 'ISA IDE'... and even > with the IDE turned off in the BIOS, and a drive attached to the 'ISA IDE', > it attempted to boot from that drive, which gave me a dmesg including wdc0 @ > pci0. > > Oh, and I have no docs on the controller, and haven't found any online, and > the (many) jumpers are unlabeled. So unfortunately... Yeah. Plus, the > controller is physically HUGE (lengthwise). Not all of the machines I've > tried can even get it into a slot.
Try looking for "Total Hardware '99" - your controller might be documented in there. > > (Just found this... Looks pretty similar. > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250157575469 ) > >> As you have probably (re)discovered, the OS takes its cues on the >> drive geometry from the BIOS. On modern IDE drives, it just doesn't >> matter, but on an MFM drive, head 3 was really head 3, cylinder 138 >> was really cylinder 138, and there were 17 sectors on each track, and >> where the OS requested is where the controller placed the drive and > > Yes. 615/4/17, although I've also seen 616 mentioned (it's an ST225 with no > values on the label). The partition ends at 613 (i.e. 614th cyl), and I > think the last track is the landing zone, so I'm going to go with 615 if I > can get to that point... > >> where the data came off, so yes, it really needs to be "right". Yes, >> source could probably be modified to hard-code this in the OS, but >> getting it right would be "interesting"...and very much in untested >> code paths, I suspect. > > Well, on the one hand this seems like something you should be able to shoot > yourself in the foot with if you really want, not to mention another way to > be BIOS-agnostic. On the other, this is about the only time it would ever > matter, so I guess the kernel doesn't need the added complexity of a way to > change it... > >> good luck, I'm curious how it all works out... > > Well, I can post the dmesg and fdisk when I get there. :) > > Thanks. > > -- Aaron Mason - Programmer, open source addict I've taken my software vows - for beta or for worse
