41 ms·

I had my own text library where I converted to/from ASCII internally. There was nothing special about the 6 bit boundaries, so you could use any number of bits

by mark-r 7y ago

I had my own text library where I converted to/from ASCII internally. There was nothing special about the 6 bit boundaries, so you could use any number of bits per character that you wanted until it was time to interact with the rest of the system. By the time I used it they had extended the character set to include lower case by using a special prefix character.

tpmx 7y ago
Why were you doing text processing on a "scientific computer" in the first place? :) Sounds like there may be an interesting story there, maybe.
- mark-r 7y ago
  It was the general student computer at the University of Minnesota, and the uses it were put to were all over the map. Despite being optimized for number crunching it was an amazing general purpose computer. The most interesting architectural feature was that all I/O was relegated to peripheral processors so that the main CPU could run unimpeded.
  - Gibbon1 7y ago
    I think UCLA had a CDC 6600 being used as a time share system. My memory is very hazy though. We used it remotely via 150 baud terminals. On hot days occasionally bits would get scrambled on the way there and back. 10 PRINT "YOUR MOMMA" came back as 10 PRINT "KOUR IOMMA"
- BadThink6655321 7y ago
  Supercomputers need compilers, et. al. And now I need to go back and revisit the Pascal compiler for those machines...
  - dfox 7y ago
    The toolchain does not have to run on the supercomputer itself. Most supercomputer architectures have self-hosting toolchains there are also supercomputers that do not. Also compiling or even debugging programs directly on the machine is in most cases plain waste of (expensive) computing resources and it is not that one would ever have only the supercomputer and not any other computers (in fact, many traditional supercomputers cannot boot on their own and have to be booted by some kind of frontend computer).
    - tpmx 7y ago
      Did they also have that at launch time(s), back in the 60s/70s?
      - B1FF_PSUVM 7y ago
        I believe so, the comp. arch. textbooks were pretty emphatic on the description of the CDC 6600 as "full of peripheral processors", e.g. for I/O and printing, etc. Deliberately, not something tacked on later as an afterthought.
        dfox 7y ago
        I cannot find any information about whether one of the peripheral processors in CDC 6600 (which were full-blown CPUs, not glorified DMA engines as in Cray-1 or System/360) has some kind of system management role. On the other hand Cray-1 needs not one, but two frontend computers to work (one is DG Nova/Eclipse supplied by Cray which actually boots the system and second one has to be provided by customer and is essentially an user interface)
        pinewurst 7y ago
        What do you mean? The CDC OSes actually ran on the PPs and for all intents and purposes managed the system. The two-headed video console was hardwired to a PP as well, and used to managed the system.
        vajrabum 7y ago
  - tpmx 7y ago
    That makes a lot of sense. I bet a lot of these "scientific" machines ended up primarily being used for software development... http://www.lysator.liu.se/hackdict/split2/pascal.html http://www.lysator.liu.se/hackdict/split2/pascal.html > Pascal n. An Algol-descended language designed by Niklaus Wirth on the CDC 6600
- dwheeler 7y ago
  I do have a story, I hope it's interesting. The CDC 6600 was used as the student mainframe for George Mason University (GMU) in Northern Virginia in the 1980s. For engineering classes (e.g., electronics engineering) the 6600 was still excellent; it could run simulations far faster than many systems that had been built later, and it was certainly faster at that task than the personal computers of that early time (Apple //es or the original IBM PC). People also used the 6600 for writing text, compiling, etc. The computer was a terrible match for that, but it was fast enough that the mismatch of capabilities still made it useful for the purpose. Oh, and a quick aside: Today's computers are much faster, but much of that speed is taken away by software that's more functional and less efficient. I once shared an IBM PC (4.77MHz) among 16 users. If your computer software is generally efficient, and you're willing to reduce what it does, a single computer can serve a remarkably large number of users. Nobody worried about font selection, for example. So it was with the 6600; it could serve many users, if carefully managed. Now for the story, which I can't confirm but I believe to be true. At the time GMU was a scrappy new local university. It was in a great location (Northern Virginia, which was expanding rapidly). However, although it was a state university, it had little support from the capital (power is divided among counties, and the rural counties easily outvoted Northern Virginia). GMU's president, President Johnson, had much bigger plans for GMU. So Johnson arranged for a hand-me-down supercomputer (the 6600) for nearly nothing. This computer was considered obsolete by then, and it was terrible at text processing. Even so, it was still fast enough to be useful, and more importantly, it was a supercomputer, even though it had been obsoleted. My understanding is that Johnson sold the pitch of "GMU has a supercomputer now" to all the local businesses, asking them to help fund GMU & cooperate in various ways. The local businesses did, greatly so. I suspect most of the businesses knew the "supercomputer" wasn't a current speed champion, and as I far as I know no lies were told. But that wasn't the point. The pitch "we have a supercomputer" was good enough to make it much easier for some people in various businesses to justify (to their cohorts) donating to GMU & working with GMU. Many businesses in Northern Virginia wanted GMU to succeed, because they would greatly benefit long-term with a good university in their backyard... they just needed a good-enough story to win over those who might veto it internally. This "we have a supercomputer" pitch (and other things) worked. Once GMU got "real" money, they invested it, e.g., they upgraded (and kept upgrading) to better equipment. GMU grew quickly into quite a powerhouse; it's now the largest state university in Virginia. One of GMU's distinctives is the huge number of connections it has to local businesses and government organizations. Originally this was because GMU couldn't rely on state funding, but the need to interconnect with local organizations led over time to an emphasis on applying academic knowledge to real-world problems. It's interesting to see how problems + scrappiness can lead to long-term cultures within an organization. Johnson passed away in 2017 ( https://www2.gmu.edu/news/427091 https://www2.gmu.edu/news/427091 ), but his legacy continues.

by mark-r 7y ago

tpmx 7y ago

Why were you doing text processing on a "scientific computer" in the first place? :) Sounds like there may be an interesting story there, maybe.

mark-r 7y ago
It was the general student computer at the University of Minnesota, and the uses it were put to were all over the map. Despite being optimized for number crunching it was an amazing general purpose computer. The most interesting architectural feature was that all I/O was relegated to peripheral processors so that the main CPU could run unimpeded.
- Gibbon1 7y ago
  I think UCLA had a CDC 6600 being used as a time share system. My memory is very hazy though. We used it remotely via 150 baud terminals. On hot days occasionally bits would get scrambled on the way there and back. 10 PRINT "YOUR MOMMA" came back as 10 PRINT "KOUR IOMMA"
BadThink6655321 7y ago
Supercomputers need compilers, et. al. And now I need to go back and revisit the Pascal compiler for those machines...
- dfox 7y ago
  The toolchain does not have to run on the supercomputer itself. Most supercomputer architectures have self-hosting toolchains there are also supercomputers that do not. Also compiling or even debugging programs directly on the machine is in most cases plain waste of (expensive) computing resources and it is not that one would ever have only the supercomputer and not any other computers (in fact, many traditional supercomputers cannot boot on their own and have to be booted by some kind of frontend computer).
  - tpmx 7y ago
    Did they also have that at launch time(s), back in the 60s/70s?
    - B1FF_PSUVM 7y ago
      I believe so, the comp. arch. textbooks were pretty emphatic on the description of the CDC 6600 as "full of peripheral processors", e.g. for I/O and printing, etc. Deliberately, not something tacked on later as an afterthought.
      - dfox 7y ago
        I cannot find any information about whether one of the peripheral processors in CDC 6600 (which were full-blown CPUs, not glorified DMA engines as in Cray-1 or System/360) has some kind of system management role. On the other hand Cray-1 needs not one, but two frontend computers to work (one is DG Nova/Eclipse supplied by Cray which actually boots the system and second one has to be provided by customer and is essentially an user interface)
        pinewurst 7y ago
        What do you mean? The CDC OSes actually ran on the PPs and for all intents and purposes managed the system. The two-headed video console was hardwired to a PP as well, and used to managed the system.
        vajrabum 7y ago
- tpmx 7y ago
  That makes a lot of sense. I bet a lot of these "scientific" machines ended up primarily being used for software development... http://www.lysator.liu.se/hackdict/split2/pascal.html http://www.lysator.liu.se/hackdict/split2/pascal.html > Pascal n. An Algol-descended language designed by Niklaus Wirth on the CDC 6600
dwheeler 7y ago
I do have a story, I hope it's interesting. The CDC 6600 was used as the student mainframe for George Mason University (GMU) in Northern Virginia in the 1980s. For engineering classes (e.g., electronics engineering) the 6600 was still excellent; it could run simulations far faster than many systems that had been built later, and it was certainly faster at that task than the personal computers of that early time (Apple //es or the original IBM PC). People also used the 6600 for writing text, compiling, etc. The computer was a terrible match for that, but it was fast enough that the mismatch of capabilities still made it useful for the purpose. Oh, and a quick aside: Today's computers are much faster, but much of that speed is taken away by software that's more functional and less efficient. I once shared an IBM PC (4.77MHz) among 16 users. If your computer software is generally efficient, and you're willing to reduce what it does, a single computer can serve a remarkably large number of users. Nobody worried about font selection, for example. So it was with the 6600; it could serve many users, if carefully managed. Now for the story, which I can't confirm but I believe to be true. At the time GMU was a scrappy new local university. It was in a great location (Northern Virginia, which was expanding rapidly). However, although it was a state university, it had little support from the capital (power is divided among counties, and the rural counties easily outvoted Northern Virginia). GMU's president, President Johnson, had much bigger plans for GMU. So Johnson arranged for a hand-me-down supercomputer (the 6600) for nearly nothing. This computer was considered obsolete by then, and it was terrible at text processing. Even so, it was still fast enough to be useful, and more importantly, it was a supercomputer, even though it had been obsoleted. My understanding is that Johnson sold the pitch of "GMU has a supercomputer now" to all the local businesses, asking them to help fund GMU & cooperate in various ways. The local businesses did, greatly so. I suspect most of the businesses knew the "supercomputer" wasn't a current speed champion, and as I far as I know no lies were told. But that wasn't the point. The pitch "we have a supercomputer" was good enough to make it much easier for some people in various businesses to justify (to their cohorts) donating to GMU & working with GMU. Many businesses in Northern Virginia wanted GMU to succeed, because they would greatly benefit long-term with a good university in their backyard... they just needed a good-enough story to win over those who might veto it internally. This "we have a supercomputer" pitch (and other things) worked. Once GMU got "real" money, they invested it, e.g., they upgraded (and kept upgrading) to better equipment. GMU grew quickly into quite a powerhouse; it's now the largest state university in Virginia. One of GMU's distinctives is the huge number of connections it has to local businesses and government organizations. Originally this was because GMU couldn't rely on state funding, but the need to interconnect with local organizations led over time to an emphasis on applying academic knowledge to real-world problems. It's interesting to see how problems + scrappiness can lead to long-term cultures within an organization. Johnson passed away in 2017 ( https://www2.gmu.edu/news/427091 https://www2.gmu.edu/news/427091 ), but his legacy continues.