@ AC
Today's equivalent of the "cripple card" is implemented in software, not hardware, and it's called Windows.
"...And we used to do pretty much everything from the switches on the front panel – bootstrapping, diagnostics, machine code reprogramming – all on toggle switches!" the Boss burbles happily "...those were the days!" "I'm sure they were," the PFY says dryly, rolling his eyes out of the Boss' view. "Oh, that was just the tip …
Antony, I drove a DG Nova3 using RDOS. The machine was later replaced with a Nova 4C with a 25MB Winchester Drive. DG sent people out just to see it because they had never installed one with such a large fixed disc. The down side was we backed up and archived everything on 8" floppies - It was used to acquire and process data from mass spectrometers.
I remember that in the month I ordered it, I bought a 3 bedroom detached house in the UK - The Nova was about twice the price of my house, so say half a million quid in present money.
The disc unit was huge (19" rackable). You could see everything because the top case of the drive was transparent. Yes, obviously, the heads crashed on the HD after a year or two. The damaged aerofoil head had buried itself deep into the gouges in the platter. Of course these young-uns don't know that the heads in disc drives actually flew on the thin layer of air that was carried along with the rotating disc surface. I need to lie down now for my afternoon nap...
First interaction with the new and wonderful world of computing was with a CTL Modular 1 connected to a teletype over a 300baud acoustic coupler. And an ICL 1904 to which we posted punched cards - no syntax errors in our programs in those days.
Then in 1978 a PDP 11/05 (IPL from front panel switches) and a PDP 11/34 running Unix. We were so proud that our little box occupying 10 feet square in the corner of the machine room could support 25+ simultaneous users while the B6700 occupying the rest of the room could support about 10 and the cafe batch system.
Anyone remember the Burroughs memory units that displayed a Burroughs 'B' on the status lights while they were idling? I never worked out how they did that.
I can't believe there are people I look up to now who have never heard of this stuff!
Paris, because she wouldn't remember either...
I'm hurt.
I loved all of the PDP 11/34's I used. Of course they were not as reliable as more modern machines (or even 11/03s and 11/44s), but then they were built out of LS7400 TTL with a wire-wrap backplane with literally thousands of individually wrapped pins. If I remember correctly, the CPU was on five boards, with the FPU (optional) on another two. Add DL or DZ-11 terminal controllers, RK or RP-11 disk controllers, and MT-11 tape controllers, and you had a lot to go wrong.
I suspect that all of the Prime, DG, IBM, Univac, Perkin Elmer, HP systems of the same time frame had similar problem rates. Especially as they were not rated as data-centre only machines, and would quite oftern be found sitting in closed offices or large cupboards, often with no air-conditioning.
It was quite normal for the engineers to visit two or three times a month, and we had planned preventative maintenance visits every quarter.
But, the PDP 11 instruction set was incredibly regular (I used to be able to dis-assemble it while reading it), and it was the system that most Universities first got UNIX on. It had some quirks (16 bit processor addressing mapped to 18 or 22 bit memory addressing using segment registers [like, but much, much better than Intel later put into the 80286], Unibus Map, seperate I&D space on higher-end models). OK the 11/34 had to fit the kernel into 56K (8K was reserved to address the UNIBUS), but with the Keele Overlay Mods. to the UNIX V7 kernel, together with the Calgary device buffer modifications, we were able to support 16 concurrent terminal sessions on what was on paper little more powerful than an IBM PC/AT.
It was a ground-breaking architecture that should go down as one of the classics, along with IBM 360, Motorola 68000 and MIPS-1.
Happy days. I'll get my Snokel Parka as I leave.
IBM 1401 - a napkin-sketched prototype for the 360, with all the power of the same ill-used bar napkin and Shiny! Radix_40! Addressing! to access its four thousand (not 4k, four zero zero zero decimal) native storage locations made of ferrite beads. Yes, they were eight bits wide, and no, they weren't bytes. (Hint: parity bit.)
SCO XENIX86 - ten users on a vanilla XT (4.77 MHz, 640kB). Never actually sold as an official product AFAIK, but *small* ==> less opportunity for suckage.
BTDTGTtoo-small-to-wear-anymoreTS. Someone hand me the large coat, willya?
--
And the men and women (well, the men) who went to the moon? Well God bless 'em, they did it with no mouse, and a text-only black and white screen and THIRTY-TWO KILOBYTES OF RAM. Hah!
-- Three Dead Trolls, "Every OS Sucks"