"Why Some Old Computers are Interesting"

This page gives a nice recap of architectural innovations seen back in the day, in big iron machines, long before those innovations came to microprocessors:

…while today’s microprocessors are miracles of engineering, available at an almost ridiculously low price, the greater part of the performance increase is attributable to semiconductor process technology, not to architectural innovations.

The architectural history of the microprocessor is very largely the recapitulation of the architectural history of the mainframe - with the benefits of not being the first!

Examples given:

  • 1960: IBM 7030 Stretch: Instruction pipelining, pre-fetching, interleaved memory, interrupts, first use of the 8-bit byte.
  • 1962: Atlas: Paged virtual memory, hardware support for operating system functions.
  • 1962: IBM/MIT 7094 for CTSS: Two modes (user/supervisor) with privileged instructions and memory reserved for supervisor use. Executing a privileged instruction in user mode trapped to supervisor mode code.
  • 1964: CDC 6600: Instruction level parallelism with out-of-order execution, load-store - i.e. RISC - architecture, multi-threaded peripheral processor architecture, maximum performance by co-design of architecture and circuit details.
  • 1964: IBM System/360: establishment of the 8-bit byte as the norm, byte addressable memory, 32-bit word length, general purpose registers, the concept of a family of compatible machines.
  • 1967: IBM System/360 Model 67 and CP/67: Virtual machine technology (CP/67 later developed into VM/CMS).
  • 1968: IBM System/360 Model 85: Cache memory.
  • 1969: CDC 7600: 6600 innovations, plus pipelined functional units.
  • 1975: Cray-1: Vector processing (preceeded by Illiac-IV, CDC Star-100 and TI ASC).

Not entirely unrelated:
Bret Victor - The Future of Programming (video)


The thing I find very aggravating is that for much of the world computers and computing == Windows x86 PCs. Nothing existed before, nothing exists beyond. It’s like saying food is all plain bread.


I suppose that’s part of the reason we congregate here - and part of the reason I like to visit computer museums…

Here’s an album of annotated photos from a visit to Jim Austin’s sheds - not a museum, but not unlike a museum, and you can’t fault it for variety:

I agree, there’s a great deal to computing, even if you only study one generation of machines.


The younger generation is doing what we did to our ancestors, in the 1970s did we relish the 1930’s horse-drawn hoe? not likely. Now we are the ancestors, and were starting to sound just like them " those kids know nothing" & " In my day, we had to…" thing is… humanity moves on, the singular hope that someone aside a museum (and only to a small degree) will spend their lives to collect and cherish the dinosaurs (pardon the expression) of computers is only ours to cherish, “we” of the old guard and almost none of the under 30 of age, are the one cherishing these things like our grandfathers cherished their favourite axe, flintlock gun etc. It’s a reality that people before me tried to get us to adopt, pass on, your grandfathers pocket watch is nice, maybe you even bought a couple more, but really no one cares aside from antique dealers, which in our computer historical point of view, was a mass-production of "things’ that never gained a value aside from a memorial one. it is sad, and why I cherish every unit I get to play, restore or repair for someone, it just means it lasts a bit longer in time. but like the “things” of the past, only the ones visiting museums will care, and only for the moment they stand before the creation about it, then the next generation of handheld, “StarTrek” defined future technology to come next is what they are looking for… and for the '20-'30s-year-old, they will wear the shoes we wore from our ancestors as they will do the same when people will not care about their iPods or handheld devices because we will have moved further into the future again… Vintage is a grasp in a period of time before the one your stand, the roaring '20s were vintage to the people of the 60’s the '80s has been the vintage of the 2000s and the 2000s will be vintage in 2040… only 20 years from now… thus making us born in the 60’s and before, already decrepid, vintage, beings with knowledge no one born in the next decades will care about except in school manuals as historical figures of the pioneers of the early days of computers that gave them what they toy with now. sad indeed prospects from like so many like me and you, holding on to hordes of hardware most of the population would rather recycle to make an iPod or tablet with. and be rid of them. We do not like it any more than our ancestors did when we forgot how we made butter from milk in a wooden container with a stick. I don’t like it… .its what the ephemeral life of humanity is about… forward march… always.


What I have seen, then it is mostly games that children today want, when we are talking 1980’s tech or something like that. They are not really interrested in old big chunky boxes. But give them pacman-remake in original arcade feel and they are happy. Also they like to use parts of everyday tech, as kind of comtemporary pop culture. Like the floppy disc as an example.

My kids are interrested in these games, to a certain degree that is. But they are not interrested in my Amiga’s, C64’s and old 286/486/Pentium machines. They think these machines are big and clunky.

However… I have told them that I take good care of my collection, and that I wish they will keep at least the C64 replica’s that I have build. The rest they can sell, if the machines are working, because these machines will be worth a lot to specific collectors, when I am dead and 6 feet under. In that light, my collection is interresting to my children.

1 Like

I agree with what you say, but you are talking about something slightly different… I think. I was mourning the false view general public / average man on the street has of the history of computing, the details getting lost or muddled. “Bill Gates invented the Internet”, that sort of thing. Those who have experienced some earlier form of technology of course can feel wistful for it, but they don’t need to. As you said, forward march. I was not saying that “it was hard when we did it, god damn the young whippersnappers should learn how to use some obsolete piece of technology”.

1 Like

I am still working on how to set VCR clock.
The 1980’s let you see a computer in some form, rather than some SPECIAL GROUP. The modern computer is now so complex, that very few AVERAGE people can even understand what it does inside. Retro projects still let you understand , hold and modify things the way you want, like back then.Some
computers even a had manual to tell you how things work like the APPLE II.

1 Like

I think, the loss of technological knowledge that goes hand in hand with progress is generally underated. Take for instance the not-so-ancient art of plugboard programming for punch card appliances. I guess, this is mostly gone now with few interest remaining in that branch of technology. However, there are also some early-state technological artifacts that we adopted as pets, like oldtimer cars. It seems, there’s a certain chance of home computers enjoying a similar fate, of becoming of interest for the next generation, as well. And, if so, it will be because of games. Probably, the (sensorial) fun factor is a decisive quality of those “pet technologies”. (Something we were not able to see in punch card appliances.) And, as long as these “pet technologies” are around, they will be conveying a message of simpler times, when things were accessible and by this fun, regardless of this being right or wrong. Arguably, there’s a need for keeping such reminders around – that is, as long as there’s some connection to the current narrative. (Compare the reocurring theme of tangible design and interaction.)


Ah yes, the PET technologies!

My grandfather had stories of playing with cats-whisker radios, his middle-age interests having moved to hifi (and quadraphonics). He must have been just a few decades younger than the likes of Marconi who pioneered radio.

And in the same way, perhaps, I’m a few decades younger than the pioneers of Colossus and ENIAC. (I confess I haven’t looked up the dates.) I grew up tinkering with digital logic and kit microcomputers. And now in middle age (ahem) I fiddle with microcontrollers and emulators.

One fundamental aspect of computing is universality. There’s not much trace of a cats whisker in a stereo FM receiver, whereas with a modern laptop I can run emulations of 8 bit micros, or of Colossus. Or indeed, punched cards or teletypes.

And the virtual consoles are an example of this kind of thing: we can make slick and tidy virtual machines, on which youngsters can write and then play games not entirely unlike the games we played. We can, if we choose, take a semi-historical approach to teaching computational thinking, and so connect the present to the past.


An observation, which may be related to the journey of your grandfather: To me, it seems that what had been the hot, emerging field previously, but is now finally sorted out, as we were born, might be the least interesting field. E.g., in the 1940s, high frequency was the hot thing (and one of the reasons we migrated from valves to those fancy transistor thingies) – and probably also what drove your grandfather in his middle-ages. I, on the other hand, who was born when this had been sorted out already, take this sort of granted and do not only have a hard time interesting myself in this, but I also don’t know anyone who would share that kind of fascination. Not sure, if this may be generalized, but there seems to be some kind of sliding hole of technological interest. (So it may be even more remarkable, when a technology manages to keep interest alive along multiple generations.)


I see what you did there! :slight_smile: