Re: This is probably a stupid question, but...


3 Jul 1995 02:23:05 GMT

In article <MAFM.95Jun29130557@parma.cs.uwa.edu.au>, mafm@cs.uwa.edu.au (Matthew McDonald) writes:
|> Alternatively, is it possible to get
|> micro-codable processors?

There exist so-called "bit-slice" processor chips, which are
essentially a slice, typically 4 or 8 bits wide, through a
register set, ALU and associated logic. The idea is that
you put together enough slices to get the word length you
want, together with some ROM for microcode and a few other
bits and pieces, and build yourself a processor. It would
probably be feasible to build a hardware Z-machine this
way.

I might even be crazy enough to try this myself...

|> Presumably the I/O stuff can't be written in raw
|> z-machine code anyway, and so has to be done in hardware or using
|> another processor anyway.

You could probably microcode the Z-machine I/O instructions
if you made the microcode flexible enough. Alternatively,
you could invent some new, lower-level I/O primitives and
treat the official I/O instructions as "system calls" which
trap to a piece of Z-code (perhaps in a different address
space) which do the operation using the real primitives.

Hmmm... writing an operating system in Inform would be an
interesting exercise...

|> Matthew McDonald mafm@cs.uwa.edu.au

Greg Ewing, Computer Science Dept, +--------------------------------------+
University of Canterbury, | A citizen of NewZealandCorp, a |
Christchurch, New Zealand | wholly-owned subsidiary of Japan Inc.|
greg@cosc.canterbury.ac.nz +--------------------------------------+