Title : A Song of Computation Author : Tony Duell Original : A Song of Reproduction Group : Flanders and Swann Intro : The processor 'of storage 4 k byte' is (of course) a Philips P850, a minicomputer noted for its limited memory (4 k bytes was the maximum), RISC-like instruction set, and total lack of speed. After that, the PDP11/45 was a great improvement EI set = Extended Instruction Set, i.e. the XOR, Multiply and Divide instructions etc DW11-B was a DEC option to use Q-Bus cards on a UNIBUS PDP11. They are much desired by PDP11 enthusiasts, although they can cause problems NXM error = Non eXistant Memory error - what happens if there is a bus time-out during a DMA transfer Don't try to make too much sense of the spoken part in the middle It makes more sense than the original, anyway Song : I had a little processor With storage 4 K byte And with an octal program It ran throughout the night And then they optimised it It was much faster then And we loaded Fortran Programs To make it slow again Today for computation I'm as eager as can be Count me among the faithful fans of high end P - D - P High end PDP 45's the one for me With cartridge disk and EI set and 6 foot rack mount cabinet floating point boards too complete with M M U All the lowest bits either clear or set What they mean now I quite forget Still there's enough range there for national debt With my high end PDP (spoken) Who configured this for you anyway? DEC field service ?!?!? Ooooh what a shoddy job they made of it! Suprised they let you run that configuration on this processor, the priorities are all wrong. If you move the tape drive down the bus after the console port, and then re-assign the address of the system disk, then you'll still only get adequate performance if you run modified software I see you've got your system disk on the Q-Bus! Take that though a DW11-B bus convertor, and via your A-leg Mux into the ALU, If you're running multi-user, you're going to loose grants. Try to load the OS that way and what'll you get A NXM error! High end PDP RSX version 3 I've a shell right here that you won't escape On miles of 9-track recording tape 18 bit address Will prove a great success With the console switch, at a single touch The lisiting comes in double dutch But I never did care for data much With my high end PDP @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@