Date   : Wed, 21 Apr 1993 10:55:41 BST
From   : ajcd@...
Subject: BBC mailing list?

>Date: Wed, 21 Apr 93 10:35:15 +0100 (BST)
From: I Stephenson <ian@...>
>
>I've added you to the list.

Thanks.

>I'm currently trying to get a project off the ground to provide a decent shell
>environment, which is going to require a team effort on behalf of the list so
>if you could do some coding for that :-)

I've thought about this too. I normally run in my own CLI mode (part of the
Assembler/Disassembler ROM), which is really just an OSCLI dispatch loop. I'm
(slowly) writing a new version of the Assembler, which will be much more
advanced, and I've tried to make it possible for programs called via OSCLI to
return status to the command line. This means that you can implement
forward conditionals (i.e. if/then/else) as separate programs which take a
test, execute it, and scan for the then or else clause. Loops are more
complicated, because you have to save the loop body (which could be done by
saving a file pointer and handle into the current *exec file, and disallowing
loops from non-seekable input (i.e. keyboard). I'd like to have the shell
level able to execute arbitrary programs rather than just ones written for it,
within limitations. This may mean implementing a swapping system to page out
the used memory in between program execution, in which case the shell should
include as many built-in commands as possible, to reduce swapping. Or it may
mean requiring the shell to run from Sideways RAM. Or...

>Check out the ftp site (shiraz.ohm.york.ac.uk), and you'll find a copy of the 
>source to what I've done so far (the file is called something like oslayer-uue,
>and its uuencodeed and arced - bbc - decoders are also on shiraz).

I'll have a look.

a.
--
Angus Duggan, Department of Computer Science,  | Jobless, Phdless, clueless
University of Edinburgh, The King's Buildings,  | PHONE: +44(0)31 650 5126
Mayfield Road, Edinburgh EH9 3JZ, Scotland.    | INET: ajcd@...