1982
23. MICROCODE UNIX
The objectives of the project were:
- A full Version 7 UNIX implementation
without virtual addressing able to run PDP11 programs.
- To implement UNIX in a way that gave maximum compatibility
with other ICL systems.
- To fit in with ICL's plans for distributed systems and networking.
- To provide a system which would be reliable, well documented,
easily maintained and
easily upgradeable.
- To implement FORTRAN as soon as possible.
To realise these objectives, the ICL implementation required:
-
C-machine: to microcode the PERQ to become a machine
having an order code appropriate to the C language.
-
C Compiler: to change the portable C compiler to
generate orders for the new C-machine.
-
UNIX Kernel: to define the UNIX kernel from scratch
using the C-machine order code. Initially programs could only
reside in real memory (about 350 Kbytes on a 0.5 Mbyte PERQ).
-
UNIX Utilities: port the set of UNIX utilities as in
the Accent UNIX Project. As the C-machine order code was under
the control of the project, this could be defined to make this
function easier.
-
FORTRAN Compiler: to change the FORTRAN compiler
as in Accent UNIX. To move the ERCC FORTRAN compiler at a later stage.
As can be seen, some of the work in the two implementations was
very similar (porting utilities etc). The two projects shared
resources in this area.
