2.9.1 BSD on 11/34 + sc21-bm + fujitsu m2333k

[Josh Dersch]

On 12/11/15 5:50 PM, Jacob Ritorto wrote:
> Exciting stuff for a Friday night, right?  Here's a visual aid in case
> you're needing further inspiration:
> https://www.instagram.com/p/_K-zHhHvLn78Qu5ijWqMf-HBem1LKMLaEdI1c0/  The
> M2333K is the smaller one on the left with the green and yellow lights on.
> I'm booting from rl0, which contains the tuhs 2.9.1 rl02 image I wrote with
> vtserver earlier.
>
> I want to use my nice, roomy smd disk so I can pull in all the sources and
> recompile stuff and I've managed to get this *so* close to working but I'm
> getting
>
> xp0a: hard error bn xxxx cs2=1100 <MXF, IR> er1=0
>
> on every single block when I try to mkfs /dev/xp0a 4800
>
> This disk was working fine years ago via MSCP attached to the 11/73 (before
> I lost the Micro/11 power supply).
>
> Anyway, I referred to
> http://bitsavers.trailing-edge.com/pdf/emulex/SC2151001-CC_SC21tech_Jan87.pdf
> to set the emulation on the Emulex card for two rm03s and they're showing
> up in xxdp's zrmlb1 formatter, though they won't format there, screensful
> of errors.
>
> I think I set the m2333k to 32 sectors, per this manual:
> http://manx.classiccmp.org/collections/antonio/chrisq/B03P-4760-0101A_-_M2331,M2333_Micro-Disk_Drives_OEM_Manual.pdf
>
> Because XXDP is reputed to be really strict, I figured that was normal and
> then tried the Emulex on-board formatting procedure against both xp0 and
> xp4 and they formatted perfectly without error.  Guess the Emulex on-board
> stuff doesn't bother verifying much?
>
> So I think that maybe I've misunderstood the hard sectoring / sector sizing
> thing.  Does anyone remember the gist of it and would you be able to
> describe?  Do you see any other mistakes?
>
> thx
> jake
>

I'm not an expert with SMD drives and I've never used your particular 
controller (I have a slightly newer Emulex in my 11/44) but here's a 
couple of things I noted while leafing through the SC21 manual you linked:

1.) The SC21's format does *no* verification at all.  It lays down an 
initial format and that's it.  It doesn't create the bad-block list 
(more on that later).
2.) Section 6 of the manual lists a set of modifications (patches) that 
need to be made to XXDP diagnostics in order for them to work properly 
with the SC21.  This includes the ZRMAC0 formatter form RM02/RM03.  
You'll likely need to apply them; hopefully you can find the required 
versions to hack...
3.)  In addition to setting the sector size/sector count on the Fujitsu, 
did you also configure the SC21 for the appropriate drive? (see Appendix 
A)  I don't see an M2333 listed there specifically, but there might be 
something with a similar (or identical) geometry you can use instead.

Regarding the bad-block list:  You are going to need this to be 
generated properly, and the only way to do that is to run the 
appropriate XXDP formatter and exercisers.  If you have the bad block 
list for the drive, hopefully one of the diags will let you enter it, 
otherwise I suggest running *many* passes of the exercisers until they 
stop finding bad blocks.

After you have that step done, you will need to have a 2.9.1BSD kernel 
that's been compiled with bad block support, otherwise BSD will simply 
ignore bad sectors and assume the whole disk is good -- which will cause 
bad things to happen as soon as something is written over a bad sector.

(Apologies if any of the above is already old-hat; just trying to cover 
all the bases I know of...)

- Josh