[Simh] DZ11 vs DZV/DZQ11
Johnny Billquist
bqt at softjar.se
Tue Apr 10 03:22:36 EDT 2018
On 2018-04-10 09:12, Johnny Billquist wrote:
> On 2018-04-10 03:28, Mark Pizzolato wrote:
>> I see 2 approaches to adding support for different unit numbers:
>> 1) A unit number is settable uniquely for each of the 4 drives that
>> can be
>> attached to any of these controllers. This would map to a conceptual
>> Drive Unit
>> Plug. Did these exist on DEC MSCP drives?
>
> Yes they did.
I should actually add that for the RA60, RA80, RA81 and RA82, this plug
is binary coded with 8 tabs that you can cut off, and allows you to
select a unit number between 0 and 255. On the RA90 and RA92. The front
panel of the disk has a display and buttons, and you can select the unit
number from there, and it goes between 0 and 4095.
The RA70 disk has dip 8 dip switches where you can select the unit
number. The RA70, RA71, RA72 and RA73 can also be placed in a larger box
called the SA7x (I think, can't remember if the x was supposed to be
replaced with some number depending on configuration), where you then
have a display that control up to four disks in the container. Each disk
can then be managed by a front panel on the SA. And each disk has its
own unit number selectable on the front panel, and the unit number goes
from 0 to 255 (not 4095 as I said in a previous post). Or at least my
memory right now is 0..255 for the RA7x drives, but I could be
remembering wrong.
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
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