21 Sep
2015
21 Sep
'15
6:58 p.m.
On 2015-09-21 23:26, Jerome H. Fine wrote:
Then you have answered the question!!
But it there may be some possible confusion. If I remember
correctly, the RQDX3 was used with the RD54 and RX33
and the RQDX2 or RQDX3 was used with the RD53.
I could be wrong, but that is what I seem to remember.
So on a PDP-11 Qbus system, it is not possible to FORMAT the
RX50 which uses an RQDX1, RQDX2 or an RQDX3.
BUT, how is it possible to FORMAT the 5 1/4" RX33 HD floppy
which uses an RQDX3 controller?
If it can be dome with the RX33, why not with the RX50?
Good question. I don't know why, but it is correct, as far as I know.
The RQDX3 can format an RX33. Since the RX33 can be formatted for either
single density or double density, and for that floppy this actually
means it needs to be reformatted, the RQDX3 supports doing that. So I
guess the microcode in the RQDX3 just simply detects the RX50 and
refuses to do the operations required to do formatting there.
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
Jay Jaeger
wrote:
On
9/21/2015 11:34 AM, Paul Koning wrote:
For RX50? On standard PDP11s, those used an MSCP
controller, which
means the controller would have to do it. Did it? The only MSCP
controller I remember that did formatting was the UDA50.
I suppose you could on a Pro, since that had its own particularly
disgusting junk controller. But I haven't seen RX50 formatting
there. My impression was that they came factory formatted, with the
DEC-specific 10 sector per track format.
Acch. Bad memory cells. This actually was discussed back in 2002.
Some of the correspondents in that discussion are also denizens of this
mailing list, may recall I made the same mistake back then:
The diagnostic was/is:
BL-FN7AP-MC CZFNAP0 M-11 FORMTR RX50
So, just to verify, I fired up my 11/23 (which hasn't been on in YEARS),
which came right up, and inserted the floppy and booted it:
It formats:
RD51, RD52, RD53 on an RQDX1 or RQDX2
RD51, RD52, RD53, RD54, RD31, RD32, RX33 on an RQDDX2
Sorry for the confusion.
JRJ