On Jan 11, 2007, at 4:37 PM, David Boyes wrote:
Just for my curiousity. Was CP-67 the first "virtualization engine"
ever
produced? Or did some other company have this type of ability before
IBM
did it?
See Melinda Varian's "VM: Past Present and Future" paper for all the
gory details from the IBM perspective.
There were efforts at DEC with the PDP-8 OS-8 system to do some device
virtualization, but not the true simulation of CP. Probably the next
really serious virtual machine implementation was the p-System at
UCSD.
Interestingly, the first virtual machine implementation for
microcomputers was *not* the p-System, but Infocom's Z-Machine, which
they used to fit the Great Underground Empire into 48K.
zcode is still the native target of the Inform programming language,
which is probably the most popular text adventure development
platform extant. It has been extended with a virtual machine known
as glulx, which is pretty much just like zcode but with the IO handed
off to another layer (glk) and the 16-bitness removed, with the
overall effect that you have 4G rather than 128K of memory to squeeze
your game into. (later z-machine versions raised the bar to 512K
(v5,6) during Infocom's lifetime, and the text adventure community
has developed a z8 format
