• Latter-Day Punched-Tape Reader

    From Lawrence D?Oliveiro@3:633/10 to All on Tue Nov 25 05:54:54 2025
    This person has built a punched-tape reader around a Microchip PIC18 microcontroller which seems to run faster than any actual paper tape
    reader from back in the day <https://www.tomshardware.com/pc-components/storage/retro-computing-enthusiast-creates-perforated-tape-reader-designed-from-scratch-reads-data-at-about-50-bytes-per-second>.

    Creating tapes to read is a bit more involved process, requiring the
    layout of vector files that are fed to a laser cutter (!).

    Somehow I don?t think the tape is made out of actual paper, but I
    could be wrong ...

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Niklas Karlsson@3:633/10 to All on Tue Nov 25 06:13:20 2025
    On 2025-11-25, Lawrence D?Oliveiro <ldo@nz.invalid> wrote:
    This person has built a punched-tape reader around a Microchip PIC18 microcontroller which seems to run faster than any actual paper tape
    reader from back in the day
    <https://www.tomshardware.com/pc-components/storage/retro-computing-enthusiast-creates-perforated-tape-reader-designed-from-scratch-reads-data-at-about-50-bytes-per-second>.

    Creating tapes to read is a bit more involved process, requiring the
    layout of vector files that are fed to a laser cutter (!).

    Somehow I don?t think the tape is made out of actual paper, but I
    could be wrong ...

    I wonder if it could read actual vintage paper tapes. The article
    doesn't seem to say.

    Niklas
    --
    Please, if you want to solicit transoceanic transport for the purposes of buggery, TAKE IT OUT OF THE MONASTERY!
    -- Bill Cole

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Andy Walker@3:633/10 to All on Tue Nov 25 09:41:12 2025
    On 25/11/2025 05:54, Lawrence D?Oliveiro wrote:
    This person has built a punched-tape reader around a Microchip PIC18 microcontroller which seems to run faster than any actual paper tape
    reader from back in the day [...].

    They claim 50 cps. The tape readers of the '60s ran at around
    500 cps [otherwise there would have been no way to keep the mainframes
    properly fed and watered]. Specialised equipment was much faster --
    Colossus read 5000 cps [in the 1940s!] [but was, of course, secret for
    several decades]. Tape /punches/, which /had/ to be mechanical, were
    much slower, and indeed 50cps was roughly the going rate.

    --
    Andy Walker, Nottingham.
    Andy's music pages: www.cuboid.me.uk/andy/Music
    Composer of the day: www.cuboid.me.uk/andy/Music/Composers/Jessel

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Peter Flass@3:633/10 to All on Tue Nov 25 07:29:01 2025
    On 11/24/25 22:54, Lawrence D?Oliveiro wrote:
    This person has built a punched-tape reader around a Microchip PIC18 microcontroller which seems to run faster than any actual paper tape
    reader from back in the day <https://www.tomshardware.com/pc-components/storage/retro-computing-enthusiast-creates-perforated-tape-reader-designed-from-scratch-reads-data-at-about-50-bytes-per-second>.

    Creating tapes to read is a bit more involved process, requiring the
    layout of vector files that are fed to a laser cutter (!).

    Somehow I don?t think the tape is made out of actual paper, but I
    could be wrong ...

    It looked like he was pulling the tape thru by hand.

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Lars Poulsen@3:633/10 to All on Tue Nov 25 14:30:53 2025
    On 2025-11-25, Lawrence D?Oliveiro <ldo@nz.invalid> wrote:
    This person has built a punched-tape reader around a Microchip PIC18 microcontroller which seems to run faster than any actual paper tape
    reader from back in the day
    <https://www.tomshardware.com/pc-components/storage/retro-computing-enthusiast-creates-perforated-tape-reader-designed-from-scratch-reads-data-at-about-50-bytes-per-second>.

    50 cps? - That's nothing! Try 2000 cps back in the day.
    We had this in 1969:

    https://datamuseum.dk/bits/30002495

    --
    Lars Poulsen - an old geek in Santa Barbara, California

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Al Kossow@3:633/10 to All on Tue Nov 25 06:57:57 2025
    On 11/25/25 6:29 AM, Peter Flass wrote:

    It looked like he was pulling the tape thru by hand.

    Stone knives and bearskins

    You can buy used optical paper tape reader assemblies from Japanese
    CNC equipment for under $100.

    I spent a bunch of time documenting various models on bitsavers
    this year.

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Ben Collver@3:633/10 to All on Tue Nov 25 15:07:23 2025
    On 2025-11-25, Lawrence D?Oliveiro <ldo@nz.invalid> wrote:
    This person has built a punched-tape reader around a Microchip PIC18 microcontroller which seems to run faster than any actual paper tape
    reader from back in the day <https://www.tomshardware.com/pc-components/storage/retro-computing-
    enthusiast-creates-perforated-tape-reader-designed-from-scratch-reads- data-at-about-50-bytes-per-second>.

    Creating tapes to read is a bit more involved process, requiring the
    layout of vector files that are fed to a laser cutter (!).

    Somehow I don?t think the tape is made out of actual paper, but I
    could be wrong ...

    Here's a DIY paper tape puncher:

    <https://unimplementedtrap.com/paper-tape-punch>

    Toward the bottom it shows the author's process to cut thermal paper
    down to size and spool it.

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Adam Sampson@3:633/10 to All on Tue Nov 25 15:15:30 2025
    Lars Poulsen <lars@beagle-ears.com> writes:

    50 cps? - That's nothing! Try 2000 cps back in the day.
    We had this in 1969: https://datamuseum.dk/bits/30002495

    Or 5000 cps for the tape loops on Colossus in 1943: https://web.archive.org/web/20150310151804/https://www.ivorcatt.com/47c.htm

    "The practical speed at which Colossus could be operated was tested by
    loading it with a maximum length tape and increasing the speed until
    something happened. At about 9700 characters per second, the tape broke
    in one and then several places. The various sections of tape did their
    best to obey Newton's first law and travel in a straight line in the
    direction they happened to be going with an initial velocity of nearly
    60 miles per hour, and thus found all sorts of curious places in which
    to come to rest. Clearly, the maximum safe speed at which paper tape
    could be driven could not be much greater than 5000 characters per
    second."

    --
    Adam Sampson <ats@offog.org> <http://offog.org/>

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Carlos E.R.@3:633/10 to All on Tue Nov 25 18:53:54 2025
    On 2025-11-25 16:15, Adam Sampson wrote:
    Lars Poulsen <lars@beagle-ears.com> writes:

    50 cps? - That's nothing! Try 2000 cps back in the day.
    We had this in 1969: https://datamuseum.dk/bits/30002495

    Or 5000 cps for the tape loops on Colossus in 1943: https://web.archive.org/web/20150310151804/https://www.ivorcatt.com/47c.htm

    "The practical speed at which Colossus could be operated was tested by loading it with a maximum length tape and increasing the speed until something happened. At about 9700 characters per second, the tape broke
    in one and then several places. The various sections of tape did their
    best to obey Newton's first law and travel in a straight line in the direction they happened to be going with an initial velocity of nearly
    60 miles per hour, and thus found all sorts of curious places in which
    to come to rest. Clearly, the maximum safe speed at which paper tape
    could be driven could not be much greater than 5000 characters per
    second."

    It is a bit curious talking about a limit as characters per second
    instead of cm per second, though. There will be also a limit in size
    (smaller) of the holes.

    --
    Cheers, Carlos.
    ES??, EU??;

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Charlie Gibbs@3:633/10 to All on Tue Nov 25 19:01:59 2025
    On 2025-11-25, Lars Poulsen <lars@beagle-ears.com> wrote:

    On 2025-11-25, Lawrence D?Oliveiro <ldo@nz.invalid> wrote:

    This person has built a punched-tape reader around a Microchip PIC18
    microcontroller which seems to run faster than any actual paper tape
    reader from back in the day
    <https://www.tomshardware.com/pc-components/storage/retro-computing-enthusiast-creates-perforated-tape-reader-designed-from-scratch-reads-data-at-about-50-bytes-per-second>.

    50 cps? - That's nothing! Try 2000 cps back in the day.
    We had this in 1969:

    https://datamuseum.dk/bits/30002495

    I worked in a shop which had that exact unit. We had few
    applications that could run it flat-out - but the one that
    did built up enough of a static charge to crash the computer.
    We wound up hanging a grounded chain of paper clips near the
    unit so that the tape would hit it on the way out, and even
    then we had to run a kettle in the machine room to bring the
    humidity up enough to bleed off the charge.

    Thanks for the manual. I particularly like the way the cover
    shows the four tape formats that the unit could handle.
    (We only worked with 8-track tapes ourselves.)

    Back in the early days of personal computers, I saw a homebrewed
    paper tape reader which consisted of a small circuit board with
    a couple of wire guides on either side of a photocell array.
    You'd pull the tape through by hand; AFAIR it would read tape
    as fast as you could pull it.

    --
    /~\ Charlie Gibbs | Growth for the sake of
    \ / <cgibbs@kltpzyxm.invalid> | growth is the ideology
    X I'm really at ac.dekanfrus | of the cancer cell.
    / \ if you read it the right way. | -- Edward Abbey

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From danny burstein@3:633/10 to All on Tue Nov 25 19:18:10 2025
    In <H2nVQ.67755$pEH7.55701@fx18.iad> Charlie Gibbs <cgibbs@kltpzyxm.invalid> writes:

    [snip]

    Back in the early days of personal computers, I saw a homebrewed
    paper tape reader which consisted of a small circuit board with
    a couple of wire guides on either side of a photocell array.
    You'd pull the tape through by hand; AFAIR it would read tape
    as fast as you could pull it.

    There was a similar device in a 1970's Heathkit catalog.

    (Never got it, although I did build the Heathkit VTVM
    and Morse code keyer)

    --
    _____________________________________________________
    Knowledge may be power, but communications is the key
    dannyb@panix.com
    [to foil spammers, my address has been double rot-13 encoded]

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Al Kossow@3:633/10 to All on Tue Nov 25 13:38:13 2025
    On 11/25/25 11:01 AM, Charlie Gibbs wrote:
    I saw a homebrewed
    paper tape reader which consisted of a small circuit board with
    a couple of wire guides on either side of a photocell array.
    You'd pull the tape through by hand; AFAIR it would read tape
    as fast as you could pull it.

    Oliver Audio Engineering OAE80 https://deramp.com/swtpc.com/OAE80_Reader/OAE80_Index.htm

    the wire tape guide was the clever part



    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Rich Alderson@3:633/10 to All on Tue Nov 25 18:19:18 2025
    "Carlos E.R." <robin_listas@es.invalid> writes:

    It is a bit curious talking about a limit as characters per second instead of cm per second, though. There will be also a limit in size (smaller) of the holes.

    Why do you think it odd?

    Paper tape represents characters as sets of holes punched across the width of the tape, perpendicular to the direction of travel and rigidly aligned.

    It thus makes perfect sense to describe both input and output in terms of the number of such sets of holes to be punched or interpreted in a single time unit.

    cm/sec would not tell you anything about the processing speed of either input or output without a conversion factor of chars/cm, so why bother with that extra step?

    --
    Rich Alderson news@alderson.users.panix.com
    Audendum est, et veritas investiganda; quam etiamsi non assequamur,
    omnino tamen proprius, quam nunc sumus, ad eam perveniemus.
    --Galen

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Charlie Gibbs@3:633/10 to All on Wed Nov 26 05:08:46 2025
    On 2025-11-25, Rich Alderson <news@alderson.users.panix.com> wrote:

    "Carlos E.R." <robin_listas@es.invalid> writes:

    It is a bit curious talking about a limit as characters per second instead of
    cm per second, though. There will be also a limit in size (smaller) of the >> holes.

    Why do you think it odd?

    Paper tape represents characters as sets of holes punched across the width of the tape, perpendicular to the direction of travel and rigidly aligned.

    It thus makes perfect sense to describe both input and output in terms of the number of such sets of holes to be punched or interpreted in a single time unit.

    cm/sec would not tell you anything about the processing speed of either input or output without a conversion factor of chars/cm, so why bother with that extra step?

    The same applies to magnetic tape. With magnetic tape, it's more common
    to refer to a tape as being written at a number of bytes per inch. Tape
    drives vary widely in the speed they move the tape; description of a
    particular tape drive usually includes both the tape speed in inches
    per second, and the data transfer rate in bytes per second. However,
    if you're trying to read a tape that was written elsewhere, you're more concerned with the density in bytes per inch; you won't be able to read
    a 1600-bpi tape on an 800-bpi drive, regardless of the speed at which
    either drive moves the tape.

    Getting back to paper tape, they're typically punched at 10 characters
    per inch. If you have an oddball tape punch that does, say, 15 characters
    per inch, its tapes quite likely won't be readable by a 10-cpi reader - especially the mechanical reader found on, say, a 33ASR Teletype.

    In the end, both figures have their place: density in characters per
    unit length determine whether the tape is interchangeable at all,
    while the speed at which the tape moves determines how much data
    can be transferred in a given length of time. (It's a bit more
    complicated with magnetic tape drives, where you have to take into
    account the time it takes the tape to start and stop, and to cross
    inter-record gaps.)

    --
    /~\ Charlie Gibbs | Growth for the sake of
    \ / <cgibbs@kltpzyxm.invalid> | growth is the ideology
    X I'm really at ac.dekanfrus | of the cancer cell.
    / \ if you read it the right way. | -- Edward Abbey

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Johnny Billquist@3:633/10 to All on Thu Nov 27 20:15:28 2025
    On 2025-11-25 06:54, Lawrence D?Oliveiro wrote:
    This person has built a punched-tape reader around a Microchip PIC18 microcontroller which seems to run faster than any actual paper tape
    reader from back in the day <https://www.tomshardware.com/pc-components/storage/retro-computing-enthusiast-creates-perforated-tape-reader-designed-from-scratch-reads-data-at-about-50-bytes-per-second>.

    Creating tapes to read is a bit more involved process, requiring the
    layout of vector files that are fed to a laser cutter (!).

    Somehow I don?t think the tape is made out of actual paper, but I
    could be wrong ...

    50 bytes per second reading is much slower than old time paper tape
    readers. I've used ones that did 300 cps when reading. I think punching
    was about 50 cps.

    Johnny

    --- PyGate Linux v1.5.1
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)