13 Feb
2020
13 Feb
'20
4:55 p.m.
On Feb 13, 2020, at 7:35 PM, Timothe Litt <litt at
ieee.org> wrote:
...
Someone wrote a DECtape driver for VAX - I think Stan R., though it wasn't supported.
DECtape controllers are odd devices - the TD10 is reasonably smart, but the others put
realtime constraints on the drivers that could be hard to meet. Anyhow, by the time the
VAX came out, TU58 and Floppies were cheaper and denser media.
TU58, denser perhaps, but vastly less reliable and utterly despised by pretty much
everyone at DEC. Also very much slower.
I heard that the VMS DECtape driver was by Andy Goldstein. The report also mentioned that
it supposedly did "overlapped seek", just as the TOPS-10 driver does, but unlike
PDP-11 DECtape drivers. I never saw a system that actually had one, unfortunately.
paul
14 Feb
14 Feb
6:31 a.m.
I recall some of the team in Small systems/PDP8 lab playing with audio
cassette drives as storage for low cost PDP8, before the VT78. A
couple of others of us, were playing with real cheap video modulators.
As an aside, that got me playing with ideas for a radar jammer....
something that would work on 12 volts with a pretty fast slew rate, it
had harmonics that drove the FCC site in maynard nuts. I sued some of
that design in the DMC modem. I did enjoy the test with the hand held
radar gun.. device redesigned no range gate pull off tech, just over
powering signal. Almost bent the indicator on the hand held radar
unit. Probably should have told the cop I was gonna turn it on.
On Thu, Feb 13, 2020 at 7:55 PM Paul Koning via cctalk
<cctalk at classiccmp.org> wrote:
On Feb 13, 2020, at 7:35 PM, Timothe Litt
<litt at ieee.org> wrote:
...
Someone wrote a DECtape driver for VAX - I think Stan R., though it wasn't supported.
DECtape controllers are odd devices - the TD10 is reasonably smart, but the others put
realtime constraints on the drivers that could be hard to meet. Anyhow, by the time the
VAX came out, TU58 and Floppies were cheaper and denser media.
TU58, denser perhaps, but vastly less reliable and utterly despised by pretty much
everyone at DEC. Also very much slower.
I heard that the VMS DECtape driver was by Andy Goldstein. The report also mentioned
that it supposedly did "overlapped seek", just as the TOPS-10 driver does, but
unlike PDP-11 DECtape drivers. I never saw a system that actually had one,
unfortunately.
paul
1778
days inactive
1778
days old
1 comments
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