There was a trick to the low level format which involved subtracting 2 from something. eg. when the formatter asks for the number of cylinders or the last cylinder, you subtract 2 from the actual number. I'm sure I'm not imagining the -2 aspect, but I don't recall exactly what it applies to... I think it is number of cylinders or total number of sectors or something like that.
Found some notes...
Helmut Post in Germany was working on figuring out the Sun20 LLF procedure (ca. 2005 I think); I haven't seen a posting from him in a while, so he may not be fiddling with Lisas any more. I'm confident he would have figured it out... maybe one of the other folk in Germany know the details.
Commands for the controller board per Helmut:
> "F" Format
> "BI" Burn In - - Ten hour test. "Format Media" is test one ? ?
> "V" Verify
> "D" Diagnosis
> "DR" Dump Register
In a later email, I found "In the meantime, you might see if the "F!" command is useful." Which suggests to me that "F!" is a useful variant of the formatting command. (eg. perhaps the single character "F" command doesn't actually work?)
The following questions are asked for in their formatting program (per Helmut or Larry Parks, not sure):
>> a). Last Cylinder Number:
>> b). Number of Heads:
>> c). Number of Sectors:
>> d). Pre-Compensation Cylinder:
>> e). LUN Status Byte:
>> f). Flag Byte:
>> g). Interleave Number:
I believe:
- the last cylinder Number is the value that should be entered 2 less than one would expect.
- values are entered in hex
- LUN and Flag bytes should be 0
In a thread regarding the Sun40, I found this:
Mystery solved. I find that:
The drive formatter in 1.0.18 supports a maximum of 32 MB, while in 1.1h (and MW+II) it is 2 GB.
As long as you _format_ the drive while running 1.1h or MW+II, you can use more than 32 MB, even if you install 1.0.18 on it.
If you format a drive > 32 MB while running 1.0.18, you will probably have I/O errors when using the drive, but these will only occur when reading a sector that has not been written to, so the error may take a long time to appear.
... the Sun20s were notorious for not showing up. I don't know if this was drive specific, or MW+ version specific or what. If you can't get it to appear in Expert mode, restart and try again.
Long ago I heard from a reliable source that you should not power up a Sun20 without the data cable attached to the Lisa. In some cases this screwed up the formatting and the drive had to be sent back to SR to be fixed. I don't know if whatever caused this problem may influence what you are doing {attempting to LLF the Sun20}, but you may want to try both powering-down and not-powering-down the drive when switching from formatting to the installer.
I'll update this post if I find more
