[HECnet] DU11 vs. DUV11

-----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