HP9133 user guide...?

[Tony Duell]

>       I don't remember where I found that but it looks like HP uses a
> common board for the various models and sets the capacity to match the
> drive via the jumpers.

I beleive there are at least 2 main versions -- the older one in the 
all-metal case (which, IIRC had separate floppy and hard disk controller 
boards, linked ot the same HPIB connector) and the later one in the 
'shoebox' with the plastic front/top cover.

I have only the latter. There's a set of 4 links on the controller PCB 
that are labelled 'Ident Sra'. They link to an input port on the 6809 
bus, and seem to define the drive geometry. I do know that this is 
checked on power-up, and if the link setting doesn't match the drive, you 
get an error. I presume there's a look-up table in the firmware 
somewhere, but I've not looked for it yet.

-tony