Low level format a MFM HD on amiga KS 1.3

[snowpile79]

I have kickstart 1.3 on my A2000 with an A2090 hard disk controller hooked to a miniscribe 3053 MFM hard disk. The hard disk still works ok but it has some flaky cylinders. Id like to low level format the drive. I think HDtoolbox in workbench 3.1 has a low level format button but I have ks 1.3 as mentioned. Looking on aminet I just cant seem to find a low level format tool. On the a2090 install disks I dont see one either. I know you arent supposed to low level format new disks but for old MFM drives its how you refresh the geometry on the drive. Anyone know of any tools? The support software for the a2090 is kind of disappointing compared to the supra tools or gvp hardware.

[Matt_H]

I don’t know the details, but earlier editions of the “Introducing the Amiga 2000HD” and “Introducing the Amiga 2500” manuals assume a 2090 controller rather than a 2091 and should outline the procedure. DLH’s site has one or both of them. That plus the 2090 floppy disk should get you going.

Also remember that Commodore’s hard drive prep utilities in the 2090/1.3 era were shell scripts rather than GUI tools. On the 2091 disk, at least, the PrepHD and/or FormatHD scripts took care of a low level format—2090 might be similar.

[snowpile79]

Ok wonderful Ill check that out. What site is DLH’s site? Sorry. Something to do with Dave Haynie? Similar to his initials.

Yeah I learned the 2090 tools were just automating the format command and the prephd command did the geometry on the first two cylinders as the res0 device. Oddly enough when I enter the bad geometry table into the prep command when it asks later when I start formatting the partitions the format command still trys to format the bad cylinders and chews on them. That was a bit annoying too. Anyways thanks for the tips just fill me in on what that website is .

[Jope]

DLH's site is bombjack.org.

You really need to use the A2090 install disk and its prep command. The 2090 is a lot more involved when setting up than an RDB capable controller is.

The A2090 FAQ will also help.
http://www.lysator.liu.se/amiga/hard/guide/A2090.guide

[snowpile79]

OK so I did go to the bombjack site and grab all the manuals. No mention of low level formatting in the manuals unfortunately. I did try the idea of the A2091 tools. The only tool able to do a low level format with the A2091 tools is the old old version of HDToolbox on the install disk. I did feed in the hddisk.device driver into HDToolbox but it seems to only support scsi or XTIDE not MFM. It scanned the scsi bus side of the A2090 so if I had old SCSI drives it likely would have worked but I have an MFM HD. I scoured aminet again for a tool. Theres this BHformat tool that claims to support low level format but it hinted at only supporting SCSI. I poked at it anyways and seemed like a dead end for sure.

It seems as if theres no low level format tools for the old MFM drives unless there is a secret to getting hddisk.device to work on the MFM side in the old old HDToolbox that comes on the A2091 install disks.

With that said I'll admit that I eventually pulled the Hard Disk out of the Amiga and low level formatted the drive in my XT PC on a WD hard disk controller. I could have used my bridgeboard I guess but thats in another amiga and if I was pulling the drive out I might as well just use the PC. The Low level format worked fine in the PC. All of the random bad cylinders were completely fixed by the low level format. The drive still has a section of 20 cylinders that totally went but luckily they are all in a row so I just create my partitions to avoid them. This miniscribe drive (the 3053 model) has a voice coil head and has a whole platter dedicated to head positioning (no stepper motor that wears out) so hopefully this drive will last even longer. The ole girl is happy again. Thanks for all the other ideas even if they didnt pan out. I guess Commodore in those early days didnt find it important for users to be able to low level format.

[Jope]

You must always low level format the MFM drive on the controller it will be used with. Moving MFM drives across controllers without a LLF will either not work or result in you having a bad time otherwise.

The A2091 tools will not do anything with an A2090 card, just forget everything about RDB and HDToolBox and any other "modern" partitioning tool with the A2090.

Commodore absolutely provided tools to LLF and partition an MFM drive with their MFM controller, but you must use the correct ones.

Here is the manual, it is also quite comprehensive.
https://commodore.bombjack.org/amiga...39;s_Guide.pdf

The A2090 lowlevel format tool is called "prep" and it is on the A2090 install disk
TOSEC has several:
A2090 Hard-Disk Utilities v3.0 (1989)(Commodore)(A2000)[m].zip
A2090 A2000HD-A25000 HD ReInstall Disk v1.0 (1989)(Commodore).zip
A2090 HD Install Disk (1987)(Commodore).zip

Please check the A2090.guide in my link, it teaches you how to make the mountlist for the RES0: partition and then how to LLF with the prep tool. You also enter the defect list when prep asks you to.

If your A2090 is not autobooting, you will naturally need to have hddisk and its icon in the expansion dir of your boot disk for binddrivers to pick it up. The 2090 install disks I listed above should all be bootable + have the driver in expansion.

RES0: will not be visible during normal use, it is only for the prep tool. DH0: will be automounted once the driver is loaded. Any further partitions after DH0 must be mounted from a mountlist. DH0 cannot be FFS under 1.3.

[snowpile79]

Ok so the Prep tool DOES do a low level format. Interesting. OK. I did use PREP and did input all the bad blocks in which did create RES0: and populate the first two blocks with data. It also created the first DH0: boot partition (even though I have a non-booting A2090 currently I have a line on a booting A2090a which I will swap to shortly). Prep did not seem to actually do a full low level format though. It seemed to just quickly write the first two blocks immediately within 1 second and quit with no errors/success. Then after doing that, and prep creating DH0 I went and created FH0 and FH1 in the mountlist and formatted those... and then the dang card chewed on formatting every bad block I already fed into the prep command (after multiple tries I created this ticket looking for another tool). I totally understand what you are saying about having to use the controller you plan to actually use the hard disk with... but I'll say this: When I did the low level format in the PC I fed all the bad blocks into the WD bios based low level format tool. It then performed how Im used to.. It spent some time low level formatting the disk (probably 15 to 20 seconds) then finished with a successful message. I then pulled it, put it in the amiga and used the prep command again (like you said, but I didnt feed any bad blocks into it this time). It did its thing, created DH0 (without chewing on the bad blocks this time which I entered into the IBM low level format tool). Then when I created and formated FH0 and FH1 same behavior it did not chew on any bad blocks I marked with the ibm low level format. Also the other bad blocks were now functioning again (well, most... just not a bunch in the center of the disk).

Yep right now I do have FH0 and FH1 in the mount list and everything is happy.

So with my experience explained above it seemed like the prep tool didnt do anything but maybe record the geometry in the first two blocks (and ignore all the bad block info I put in) although prep always succeeded. It seems like the IBM low level format got me where I wanted to be in the end (bad blocks I fed into the tool were marked, other bad blocks now format fine and the amiga is no longer trying to format the bad blocks where the prep tool seemed to ignore all the bad blocks I put in and format still chewed on them)? Odd... idk.

[Jope]

Ok, thanks for the report!

It's been a while since I played with my A2090, so I remembered wrong it seems. If it is indeed only a few sec for prep, then it does mean that prep only LLFs the first two cylinders and the rest are LLFd when you format your partitions with the format command.

Judging by everything I've gathered from the 2090, it tries to treat the hard disks logically just like physical floppy drives, case in point are the hard coded DH0 DH1 DH2 device names that are tied to hddisk.device units. In a way it makes sense in that context that the format command does both low level and high level at the same time, just like it does for a floppy drive.

I have more recent memories of the PC cards and it aligns with yours.

I wonder how the IBM LLF helped though. Perhaps you happened to have a controller that has a similar low level format as the A2090.. Bombjack.org's A2090A technical manual outlines the low level track format in there, in case you want to go investigating further.

In any case, good that you got it running!