Mr Ian Primus wrote:
> --- Kees Stravers <kees.stravers@iae.nl> wrote:
>   
> 8< snip >8
>   
>> This is what I installed my first MicroVAX
>> with. The images are 
>> still on my old site:
>>
>> http://www.vaxarchive.org/swdist/bsd/10a/index.html
>>
>> In case you are able to get a RQDX disk controller
>> and an RX50 floppy 
>> drive you can try those to get the vax to boot.
>>     
>
> I can steal an RQDX3 out of PDP-11 I have here, and
> rig up some floppies. I will probably have to go with
> 3 1/2" drives, since an RX50 only holds like 400k, and
> I don't think the RQDX3 can handle 1.2mb 5 1/4" disks
> - but I seem to remember that HD 3 1/2" disks would
> work, called RX33 or something.
Not all RQDX3s handle 1.2mb drives, it depends on the ROM version. The 
old ones only do 80 tracks single sided double density. The newer ones 
do some jiggling with side select and seek while starting up to 
determine if they have an RX50 or other type of drive. HD disks do not 
work in a RX50, you must use DD disks, the ones that were 360K on the PC.

I put up the whole story on this page:

http://www.vaxarchive.org/hw/rx50.html

The RX33 is an 1.2MB drive. That does handle HD disks. It never was in a 
MicroVAX II afaik. I believe it was in the VS2000. Some Dilog Qbus ESDI 
controllers had a RX33 connector on them too.

Kees