Date   : Tue, 30 Apr 2002 10:53:13 +0100 (BST)
From   : Sprow <rsprowso@...>
Subject: Re: Completely stuck on tube emulation

On Mon, 29 Apr 2002, Richard Gellman wrote:

> I'm working on 6502 Second processor emulation, and I've hit a brick wall.
> 
> This is the output I'm getting:
> 
> Acorn TUBE 6502 64K
> 
> Acorn 1770 DFS
> 
> COMAL
> 
> ]RANDOM_COMMAND
> AND nVAL (MOD  LIST LN NEW DEG ASN nREPEAT ACS @)iAND $PI e$AND $ACS
> e$EXP VAL  REF NEW UNTIL PI END TAN STR$  }RAD ACS RUN DIV   3
> REPEAT ACS $ ACS  LOG VAL  TO RAD  UNTIL INT VAL (8$PI ebAND bEXP DEG
>  EXEC random_command
>       ^
> ]
> 
> (I'm using COMAL, because BASIC just hangs when you type anything except a *
> command)

Nothing like changing the test criteria to get the results you want!

At a first pass,I think your BRK handling is shot.I can't remember whether
the error message gets copied over the Tube to the host so that SW ROMs
get a look at it - at the very least I'd expect a "BRK encountered"
service call to go round.

The garble output there looks like BASIC keywords not COMAL.What's in the
BRK vector in the host?

Someone somewhere then needs to restart the language,usually the Tube
language's BRK handler.However,the Tube code in the host may want a look
in here - it's been ages since I disassembled that so can't remember,
Sprow.