Date   : Mon, 15 Aug 1994 10:34:07 +0100
From   : jfid@... (James Fidell)
Subject: Re: Late-night problemo!

"Chris 'Maths Lover' Rae" wrote:

> Don't even look at the time on this message... I've got kind of stuck 
> into trying to get BASIC working.
> 
> However...
> 
> I havew a bit of a problem which I'd appreciate if someone could solve. I 
> have put the BASIC ROM in at &8000 as recommended and not yet supported 
> ROM paging via &FE30. However, during execution the O/S puts &F into 
> &FE30 (is that paging in BASIC?

I believe that &0F is the default language ROM.

>                                  The ROMs are in different places on my 
> Beeb) and then (via the instruction at &F17B) does a JSR &8003. This 
> causes my emulator to report a non-existent instruction - opcode &1F. 
> I've had a look at the BASIC ROM and &1F is indeed the instruction at 
> &8003. Just to make sure it wasn't my instruction list (which has been 
> known to be a bit dodgy in the past!) I checked up with ADT on the Beeb. 
> It reports &1F as being a non-instruction too.
> 
> Where have I gone wrong? There is no way (as far as I know) that location 
> &8003 could hold anything other than &1F bearing in mind that BASIC is a 
> ROM. Help! I'm going to bed before this drives me up the wall!

I have a feeling that the OS might think that you have a service ROM
rather than a language ROM.  I don't know why this should be, though.

James.

-- 
 "Yield to temptation --             |
  it may not pass your way again"    |     jfid@...        
                                     |
        - Lazarus Long               |              James Fidell