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Thread: Using embedded micros for emulation/replacement of various I/O of classic computers

  1. #1

    Default Using embedded micros for emulation/replacement of various I/O of classic computers

    Going Forth from the C of compile/load/debug cycles.

    Say you want to run a PDP11 from your iPhone or what ever.
    The ESP32 with WIFI can be a fun way to deal with such things. At the Maker Faire, Dr. Ting will run a workshop using the ESP32. It is not specific to classic computers but with a little imagination one can create various uses to be used with our clasic machines. If your going to the Maker Faire here in the Bay Area, this should be an interesting workshop.

    Sunday 1:30 - 3:00pm - Zone 3
    ESP32 WiFi Microcontroller Workshop
    Chen-Hanson Ting
    https://makerfaire.com/maker/entry/70167

    Register at: $20
    https://www.eventbrite.com/e/esp32-w...on-60628075205

  2. #2

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    The trend nowadays is using another and far more powerful processor as an I/O processor to the classic processors. I personally was not comfortable with this approach because now I have to write software for two different processors and debug the complex interactions between them. It seems unnecessarily complex. The other discomfort is explaining that approach to newbie (like my son) who wondered why handicapping a powerful modern processor to serve an old/slow processor, when the job can be done simpler and faster with the powerful modern processor alone. Newbie has no love for the classic processors so wouldn't understand the passions in resurrecting old processors, but I also can see the paradox of crippling a powerful modern processor to assist an old processor resulting in a complex, lower performing dual processor system. It does seem like a quixotic quest.
    Bill

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    Most post-minicomputer stuff isn't terribly interesting. I can see how a young one might get bored.

    Try emulating some of the really old hardware, say, an IBM 650 or 1620. That might tickle his curiosity.

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    Quote Originally Posted by Chuck(G) View Post
    Most post-minicomputer stuff isn't terribly interesting. I can see how a young one might get bored.

    Try emulating some of the really old hardware, say, an IBM 650 or 1620. That might tickle his curiosity.
    Why on an phone. Old machines were BIG. I want switches and lights. Done the SSEM/Baby in FPGA with real switches but VGA Display for CRT so I can carry it....

    https://hackaday.com/2016/01/06/baby...er-on-an-fpga/

    I would like to do a Ferranti Pegasus next.....

    Pegasus_computer_front_console.jpg
    Dave
    G4UGM

    Looking for Analog Computers, Drum Plotters, and Graphics Terminals

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    Quote Originally Posted by g4ugm View Post
    Why on an phone. Old machines were BIG. I want switches and lights. Done the SSEM/Baby in FPGA with real switches but VGA Display for CRT so I can carry it....

    https://hackaday.com/2016/01/06/baby...er-on-an-fpga/

    I would like to do a Ferranti Pegasus next.....

    Pegasus_computer_front_console.jpg
    That is cool. Still, a 1620 is more my style. You also need to emulate the glowing heat of 600+ tubes.
    Dwight

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    It's not just the physical stuff. The thinking about instruction sets and representation was still evolving.

    On the 1620, there's only one instruction format--and the representation is decimal. Very friendly stuff, once you get used to it. There are shortcomings that might be surprising--one of the reasons that Dijkstra hated the machine.

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    Quote Originally Posted by Chuck(G) View Post
    It's not just the physical stuff. The thinking about instruction sets and representation was still evolving.

    On the 1620, there's only one instruction format--and the representation is decimal. Very friendly stuff, once you get used to it. There are shortcomings that might be surprising--one of the reasons that Dijkstra hated the machine.
    I only every programmed a 1620 in Fortran, when I was 17/18 and was at college school. We did get to visit it once a term/semester and I was interested in an emulation. Trouble is you really need a real typewrite. I have a selectric io writer (not working too well) but was saving that for an 1130.

    The Pegasus machine code is interesting. It was designed to be programmer friendly.
    Dave
    G4UGM

    Looking for Analog Computers, Drum Plotters, and Graphics Terminals

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    Quote Originally Posted by Plasmo View Post
    the paradox of crippling a powerful modern processor to assist an old processor resulting in a complex, lower performing dual processor system. It does seem like a quixotic quest.
    I don't understand why there is almost no new software being written for older processors, after going to all of the trouble of getting them running again.

    With all of the people hacking on PDP-11s, there are no new operating systems for it.
    I would think after 20 years of people complaining that DEC OSs are encumbered, someone would just write a work-alike for RT-11, RSX or RSTS.

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    Quote Originally Posted by g4ugm View Post
    I only every programmed a 1620 in Fortran, when I was 17/18 and was at college school. We did get to visit it once a term/semester and I was interested in an emulation. Trouble is you really need a real typewrite. I have a selectric io writer (not working too well) but was saving that for an 1130.
    Learning on the 1620 and other machines of the era usually started with machine code--IBM even had coding forms for that. Assembly/Autocoder/SPS was the next step; finally, you got to a higher-level language such as FORTRAN.

    On the 1620 systems that I used, the typewriter was there, and could be handy, but programming was done with punched cards. Same with the 1130/1800 systems that I used. By the time you got to 7090 or S/360, you started with assembly of some sort, not absolute machine code.

    That might seem quaint to a young person, whose first language is probably BASIC or C (or Python, or....)

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    Quote Originally Posted by Al Kossow View Post
    I don't understand why there is almost no new software being written for older processors, after going to all of the trouble of getting them running again.

    With all of the people hacking on PDP-11s, there are no new operating systems for it.
    I would think after 20 years of people complaining that DEC OSs are encumbered, someone would just write a work-alike for RT-11, RSX or RSTS.
    That is odd! especially when compared for the IBM/370 were lots of extra stuff has been written to try and add features present in VM/SP which is licenced and un-obtainable to the older VM370 which is Freeware yet all has to be done on emulation
    Dave
    G4UGM

    Looking for Analog Computers, Drum Plotters, and Graphics Terminals

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