[Info-vax] vax4000

[nierveze]

hello,thanks all for your answers ,I have several 'drv11' cards,in fact I 
have several M7941 and several M7950,
I have looked at the M9405,it seems it is a variant of the M9400,maybe I 
have one ,sure I have several M9400,I have also looked at the 'box' ,the
BA400 (and variants B400x,R400x),are THE box of the Vax4000/400
,ant I have a VAX4000/400,so if would cost nothing to use it ,and put the
drv11-B in the bus,I looked at it:I can free slots,but it was not exactly my 
option.I thought I could use the 4000/100 in a rack ,with the rack I have 
already built (it contains raws of optocouplers to isolate the position 
encoders and the transistors that drive the two motors from the computer as 
the dish itself
is about 15m far from the room where the computer will be and so in case of 
thunder problems may be serious -I already burnt a pc!!, this small rack 
contains also a joystick to manually drive the parabola with a simple 4 ways 
switch that allows use of either manual or computer drive),so I thought that 
with a small box I could be able to interface the thing!!!I had a sudden 
idea do you think I can use the 'end' of the backplane of a ba23 box,I have 
several  of them with defunct pdp11 or Vaxstations,If my memory is good only 
the  three first slots of the backplane are special use for the processor 
and the memory ,the 5 remaining are standard Q22 slots,so a 9405 in slot 4 
position ab,a continuation card slot 4 position cd,and drv11-b slots 5and6
what do you think of this,maybe I have the 9405 and cables.
The ba23 can be installed horizontally into a standard rack.
Is there a dec field service engineer around...an old one preferably :-))))
Sure even if it is possible it would not be approved.
And all that together is as big and power greedy as the 4000/400
with the two boards added.
In a book from 1985," microcomputer control of telescopes" Trueblood
and Genet
describe the use uf a LSI11 for that task.
Thanks all for your help,I go back to my lectures to try to find a
definitive solution.
A.Niervèze
"Steven Schweda" <sms.antinode at gmail.com> a écrit dans le message de news: 
27c93d01-5ca7-406e-92d0-72b0e2dc02a9 at e4g2000vbw.googlegroups.com...
> On Oct 13, 8:41 am, koeh... at eisner.nospam.encompasserve.org (Bob
> Koehler) wrote:
>
>> [...]  you may need to design the interface
>>    using analog logic, not digital, [...]
>
>   I'd love to see a reasonable definition of "analog logic".
> My slide rule didn't have True and False on it.  (It _did_
> have a "1", but not a "0", unless you count one on the "L"
> (log) scale.)
>
>   But back to the real question, ...
>
>   A Web search for B400X, R400X, and M9405 should give you
> some idea of the hardware involved.  I doubt that the cables
> were anything special.  I never tried it, but I suspect that
> a (matched) pair of old SCSI cables (preferably shielded?)
> could do the job of connecting this stuff.
>
>   Are your "drv11 cards" actually DRV11-WA cards, or some
> other DRV11 variant(s)?
>
>   Personally, unless I already had all this hardware lying
> around, I'd be looking for some other way to have fun.
> (Something slightly more useful, for example, might be an
> Alpha LR driver which could do input as well as output on a
> parallel port.)