[HECnet] VT-62?

[Jerome H. Fine]

>Bob Armstrong wrote:

       What can be done (non-destructive suggestions only, please) with a VT-62?   This is NOT a VT52 (although it looks like one).   The VT62 is a block mode terminal that, I think, actually speaks DDCMP.   AFAIK it's incapable of being a plain ASCII terminal unless there's some hack I'm unaware of. 

If you are able to use the VT62 terminal under RT-11,
DEC supported a special variant of KED specifically
for the VT62, namely K62.SAV, as opposed to the
variant, Ked.SAV, for the VT100.   There is also a variant
of KED specifically for the VT52, namely K52.SAV, in
addition to a separate variant for the VT100, Ker.SAV,
which is used when RSTS/E is the PDP-11 operating
system.

While these two special variants of Ked.SAV, namely
K52.SAV and K62.SAV, are not generally available,
at least K52.SAV can be downloaded as part of the
binary RT-11 distribution from some of those distributions
starting with V04.00 of RT-11.   After DEC stopped
supporting the VT52 and VT62 terminals (around 1989),
the KED variants for these two terminals were still
maintained, but not longer included in the standard
RT-11 binary distributions.

All of the KED variants, including K62.SAV, can still
be produced for V05.06 of RT-11. Although it is not
possible to determine if K62.SAV is correct, the two
variants of KED which are included in the distribution
for V05.06 of RT-11, Ked.SAV and Kex.SAV, are
identical to the copies produced from the source code
when all nine of the DEC supported variants of KED
are assembled and linked.   So it seems very probable
that the K52.SAV and K62.SAV variants are correct
as well.

I am not familiar with exactly what special features
K62.SAV uses in the VT62 terminal, so it is not
possible for me to advise you in that regard.

Aside from RT-11, I am not aware of any other
application program which knows anything at all about
the VT62 terminal, let alone the differences between
the VT52 and the VT62.
   Right now the only thing I can think of is to part it out as spares for my VT52.   I have two of the latter and it looks like at least some of the major assemblies - CRT, keyboard, power supply - are identical.   I hate to do that, though, if there's a better use for it. 
If you really do have a working VT62 (or one that can
be repaired), that would be sad situation if you were
to use the VT62 are spares for the VT52.   There are
probably very few working VT52 terminals around
these days although I may still have one (it has not been
turned on for at least a few years).   I doubt that there
are even a fraction of that number of VT62 terminals
left anywhere.   On the other hand, all the VT52 and
VT62 terminals are over 30 years old.   In another 30
years, it is almost certain that no one will even know
what these terminals are, let alone that any will actually
work or that there will be systems to use them with.
So if you can use the VT62 parts to keep a VT52
in working order, it is your terminal to do as you wish.

For example, there has been no one interested in a
new variant of KED which supports the VT420 with
more than 24 lines, named (appropriately I think) the
K42.SAV, which I use under Ersatz-11.   Since there
is support, under the VT100 emulation included with
Ersatz-11, for up to 255 columns by 255 lines (in
particular for the Win32 variant), K42.SAV has
been enhanced to support both of those screen sizes,
although NOT at the same time.   In practical terms,
the best my monitor can support under the DOS
variant of Ersatz-11 is either 80 columns by 50 lines
OR 132 columns by 44 lines.   For the Win32 variant
of Ersatz-11, there is support for a screen size on the
monitor of up to approximately 200 columns by 70 lines.
Along with a much larger cut / paste buffer and some
very nice extra features for the HELP screens, I find
that K42.SAV is much improved over DEC variant,
Ked.SAV, which is limited to 24 lines.

Jerome Fine