20 Jul
2014
20 Jul
'14
11:34 a.m.
On Sun, Jul 20, 2014 at 5:46 AM, Jerome H. Fine <jhfinedp3k at compsys.to> wrote:
My question was not intended to be limited to the VT14
AS SUPPLIED!
Nor was my answer.
Rather, could the VT14 have been relatively easily
modified (i.e. without
major changes AND without having to reverse the changes OTHER than
to removing them with ONLY a screwdriver or other similar tool within
about 30 minutes) to be able to run PDP-8 software.
Yes, if you replace the memory, and DON'T want to use the built-in
video "terminal", which is useless for other software, not even having
an alphanumeric keyboard. By contrast, the VT103 hardware is entirely
usable for general-purpose software.
IN ADDITION note that since your last sentence
suggests that the VT103
is not "usable as a general-purpose computer" even in its original
configuration
as supplied by DEC, it seems helpful to correct that (possible?)
misunderstanding!
I didn't say that. My point was just that the VT103 might require ROM
replacement, so a small amount of modification might be required to
make it useful. I wasn't even considering things like adding 22-bit
addressing to the backplane, which is certainly not in any sense
required.
The VT14 needs a LOT (relatively speaking) of alteration to be useful
as a general purpose machine, and even then, a non-trivial portion of
the stock VT14 hardware will be unutilized, whereas for the VT103,
everything provided is usable.
I can't imagine any scenario in which hacking a VT14 to run general
purpose PDP-8 software makes any reaonable sense. It's marginally
more reasonable than hacking a microwave oven to run general purpose
PDP-8 software, which is also possible.