[HECnet] DU11 vs. DUV11

[Steve Davidson]

-----Original Message-----
From: owner-hecnet at Update.UU.SE 
[mailto:owner-hecnet at Update.UU.SE] On Behalf Of Johnny Billquist
Sent: Sunday, January 06, 2013 14:57
To: hecnet at Update.UU.SE
Cc: Steve Davidson
Subject: Re: [HECnet] DU11 vs. DUV11

On 2013-01-06 20:35, Steve Davidson wrote:


-----Original Message-----
From: owner-hecnet at Update.UU.SE
[mailto:owner-hecnet at Update.UU.SE] On Behalf Of John Wilson
Sent: Sunday, January 06, 2013 14:29
To: hecnet at Update.UU.SE
Subject: Re: [HECnet] DU11 vs. DUV11

From: "Lee Gleason" <lee.gleason at comcast.net>

I'm even more curious what a PDT-11 optimization is doing 
in an RSX 
driver...was there at one time an RSX product product
planned for the
PDT family?

I've never met a PDT-11/110 in person.   The docs say they were 
downline-load-only -- so what DID they run?   MRRT11?
RSX11S would certainly make sense.   Also, DEC dumped a lot of the 
PDTs to their own employees, so maybe someone made a few tweaks to 
the RSX code for their own evil purposes at home.

John Wilson
D Bit


The main target for the PDT-11 was RT-11.   It was slow.   
The floppies 
spent a great deal of time seeking.   They were the size of a small 
microwave oven.   In software services we would use it to 
test patches 
to
RT-11 and some of the layered products.   I had one for a 
time that I 
used at home over a 300 baud connection.   Tough to say whether the 
dial-up or the floppies were slower... :-)

You must be talking of the PDT-11/150 then. The /110 and /130 
sat inside a VT100 shell. Extremely similar to a VT103 (I 
actually never figured out what the difference between a 
VT103 and a PDT-11/130 is.)

If I remember right,   the /110 and /130 were TU58 based and the
backplane was a 4x4 18-bit configuration.   In the RT-11 group I seem to
remember one (or more) of those 4x4 18-bit backplanes swapped out for
the 22-bit variant.   At least one of those machines used a DSD for a
"real" system disk! :-)   It either emulated an RL01 or RL02, and an
8-inch floppy.   At that point the TU58's became data "storage" devices.
The PDP-11/23+ that I had in my office used the DSD for RT-11 and RC25's
for RSX-11M.   Wow does that bring back memories... :-)

-Steve


But I figure RSX-11S would fit those machines perfectly. 
After boot, you wouldn't even care about how slow the floppy was. :-)

	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