7 Oct
2013
7 Oct
'13
6:30 p.m.
[...]
have anything that requires 3 phases). An 11-750 is
not impossible to run
in a house or a small office.
Of the 3 original VAX series (11/725,11/730 ; 11/750,11/751 ; 11/780,
11/782, 11/785), the one I think is hardest to keep going is the 11/750
(or 751).
The 11/780 series machines are virtually all standard ICs. There are lots
of them, it is complicated. But you could probably get parts if you had to.
The 11/730 series are mostly standard ICs and PALs. The PALs are not
copy-protected, I think I have dumps of them somewhere. There are 2
custom DEC gate arrays for the memory ECC logic, but I think it is
possible to kludge the machien if those fail and get it running, albeit
without any error correction on the memory.
The 11/750 is mostly those DEC gate arrays. They are custom. There is
limited data on them (there's a handy little manual on bitsavers,
something like the '11/750 magic book' that gives pinouts, etc). But if
they faily you would probably bee looking for spare 11/750 baords to take
them from. And said boards are not common.
-tony