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updated to my MARCH web site

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  • Jeff Jonas
    2 new additions to http://ferretronix.com/march/ 2 Honeywell magtapes just arrived at MARCH. But an entire spool of just clear leader? Or was there really a
    Message 1 of 8 , Jan 23, 2012
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      2 new additions to http://ferretronix.com/march/

      2 Honeywell magtapes just arrived at MARCH.
      But an entire spool of just clear leader?
      Or was there really a totally clear magtape formulation?
      http://ferretronix.com/march/20120122/

      The Analog computer and modules:
      http://ferretronix.com/march/analog_computers/

      -- jeff jonas
    • David Gesswein
      ... Its just leader. See page 7 of ftp://bitsavers.informatik.uni-stuttgart.de/pdf/honeywell/h1800/NP-2822_H-1800_Programmers_Ref_Jun64.pdf Should have 30 & 25
      Message 2 of 8 , Jan 23, 2012
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        On Mon, Jan 23, 2012 at 12:25:22PM -0000, Jeff Jonas wrote:
        > 2 Honeywell magtapes just arrived at MARCH.
        > But an entire spool of just clear leader?
        > Or was there really a totally clear magtape formulation?
        > http://ferretronix.com/march/20120122/
        >
        Its just leader. See page 7 of
        ftp://bitsavers.informatik.uni-stuttgart.de/pdf/honeywell/h1800/NP-2822_H-1800_Programmers_Ref_Jun64.pdf
        Should have 30 & 25 foot clear leaders with normal oxide tape in between.

        http://www.computerhistory.org/collections/accession/102626699
      • RonK
        ... Hi, In my former life, I worked in a data recording laboratory with digital and analog tape recorders. The only transparent tape I ever saw was leader
        Message 3 of 8 , Jan 23, 2012
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          --- In midatlanticretro@yahoogroups.com, David Gesswein <djg@...> wrote:
          >
          > On Mon, Jan 23, 2012 at 12:25:22PM -0000, Jeff Jonas wrote:
          > > 2 Honeywell magtapes just arrived at MARCH.
          > > But an entire spool of just clear leader?
          > > Or was there really a totally clear magtape formulation?
          > > http://ferretronix.com/march/20120122/
          > >
          > Its just leader. See page 7 of
          > ftp://bitsavers.informatik.uni-stuttgart.de/pdf/honeywell/h1800/NP-2822_H-1800_Programmers_Ref_Jun64.pdf
          > Should have 30 & 25 foot clear leaders with normal oxide tape in between.
          >
          > http://www.computerhistory.org/collections/accession/102626699
          >

          Hi,

          In my former life, I worked in a data recording laboratory with digital and analog tape recorders. The only transparent tape I ever saw was "leader tape"- no recording capability.

          Ron
        • RonK
          ... Also, FIY there was head cleaning tape, which I think was called Green Tape , but I don t recall its color. Ron
          Message 4 of 8 , Jan 23, 2012
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            --- In midatlanticretro@yahoogroups.com, "RonK" <rkushnier@...> wrote:
            >
            >
            >
            > --- In midatlanticretro@yahoogroups.com, David Gesswein <djg@> wrote:
            > >
            > > On Mon, Jan 23, 2012 at 12:25:22PM -0000, Jeff Jonas wrote:
            > > > 2 Honeywell magtapes just arrived at MARCH.
            > > > But an entire spool of just clear leader?
            > > > Or was there really a totally clear magtape formulation?
            > > > http://ferretronix.com/march/20120122/
            > > >
            > > Its just leader. See page 7 of
            > > ftp://bitsavers.informatik.uni-stuttgart.de/pdf/honeywell/h1800/NP-2822_H-1800_Programmers_Ref_Jun64.pdf
            > > Should have 30 & 25 foot clear leaders with normal oxide tape in between.
            > >
            > > http://www.computerhistory.org/collections/accession/102626699
            > >
            >
            > Hi,
            >
            > In my former life, I worked in a data recording laboratory with digital and analog tape recorders. The only transparent tape I ever saw was "leader tape"- no recording capability.
            >
            > Ron
            >
            Also, FIY there was head cleaning tape, which I think was called "Green Tape", but I don't recall its color.

            Ron
          • Evan Koblentz
            ... That s what I suggested to Jeff when we looked at it.
            Message 5 of 8 , Jan 23, 2012
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              >> Also, FIY there was head cleaning tape

              That's what I suggested to Jeff when we looked at it.
            • J. Chris Hausler
              Hi Jeff, It s likely leader. Although most of us are familiar with the typical IBM style half inch tape with reflective tape strips to make the beginning and
              Message 6 of 8 , Jan 23, 2012
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                Hi Jeff,

                 

                It's likely leader.  Although most of us are familiar with the typical IBM style half inch tape with reflective tape strips to make the beginning and end of the spool (somewhere around here I still have about a half used package of these) there were other approaches and clear leader (and trailer) was a common approach as well.  The very first computer on which I wrote a program (in Algol :-) was a Bendix G-20 (later re-branded Control Data) and it used one inch wide tape on NAB hubs with clear leader and trailer to tell the drive when it was at the end.  The drives were made by Potter:

                http://www.dvq.com/ads/potter_bendix_tape_sa_11_61.jpg

                In addition these tapes were blocked and had directories like DECtape and so you used them like stringy disks.  I still have a couple of these tapes around here as well.

                 

                73, Chris Hausler


                -----Original Message-----

                >From: Jeff Jonas
                >Sent: Jan 23, 2012 7:25 AM
                >To: midatlanticretro@yahoogroups.com
                >Subject: [midatlanticretro] updated to my MARCH web site
                >
                >2 new additions to http://ferretronix.com/march/
                >
                >2 Honeywell magtapes just arrived at MARCH.
                >But an entire spool of just clear leader?
                >Or was there really a totally clear magtape formulation?
                >http://ferretronix.com/march/20120122/
                >
                >The Analog computer and modules:
                >http://ferretronix.com/march/analog_computers/
                >
                >-- jeff jonas
                >
                >
                >
                >
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              • Jeff Jonas
                ... David Gesswein ... Take me to your leader jokes aside, that s a semi-clever way to distinguish start-of-tape and end-of-tape. But it also has failure
                Message 7 of 8 , Jan 24, 2012
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                  Jeff Jonas:
                  > > 2 Honeywell magtapes just arrived at MARCH.
                  > > an entire spool of just clear leader?
                  > > http://ferretronix.com/march/20120122/

                  David Gesswein
                  > Its just leader.

                  "Take me to your leader" jokes aside, that's a semi-clever way to distinguish start-of-tape and end-of-tape. But it also has failure modes for the tapes separating from the leader depending on how they're bonded or spliced (similar to video cassettes).

                  So why's the spool labelled "high density 555" when
                  - it's 556 BPI, which is rather LOW density now
                  - it's just leader, which has NO density
                  - and it's scratched, as if it was used

                  The tape in the canister seems to have no such leader, and came with a tiny spool of the self-adhesive metallic strips for BOT sensors.

                  > See page 7 of
                  > ftp://bitsavers.informatik.uni-stuttgart.de/pdf/honeywell/h1800/NP-2822_H-1800_Programmers_Ref_Jun64.pdf
                  > Should have 30 & 25 foot clear leaders with normal oxide tape in between.

                  Thanks, that's an extremely detailed manual, but it doesn't have any footnotes to an operator's manual for tape prep (such as preferred splicing methods, tools & cement), tape drive loading & tape repair.

                  I saved it to re-read the printer description, for that describes the Honeywell conventions for the 12-channel carriage control tape and the printer interface that's similar to IBM's ANSI carriage control, but not quite the same.
                • Jeff Jonas
                  ... That makes sense particularly with the Honeywell manual explaining the clear/opaque sensors instead of checking for the metallic strip for start & end of
                  Message 8 of 8 , Jan 24, 2012
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                    > > In my former life, I worked in a data recording laboratory with digital and analog tape recorders. The only transparent tape I ever saw was "leader tape"- no recording capability.

                    That makes sense particularly with the Honeywell manual explaining the clear/opaque sensors instead of checking for the metallic strip for start & end of tape. But why is the spool not labelled as such, and why is it streaked?

                    > Also, FIY there was head cleaning tape, which I think was called "Green Tape", but I don't recall its color.

                    What struck me as odd was the spool's unusually thick solid aluminum sides, and the hub's too small for any tape drive.
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