Date   : Tue, 19 Feb 2008 12:23:08 -0500
From   : charlesb@... (Charles Blackburn)
Subject: BASIC error message - "Mis..."?

So you're well used to taking a peek or too then giving them a poke eh :P

sorry i couldnt resist

anyways, i had a thought about this (been reading intently), could it be
something as simple as flushing the print buffer or something like that?

iono, may be totally on the wrong track here.

charlie
----- Original Message ----- 
From: "Mark McDougall" <msmcdoug@...>
To: <bbc-micro@...>
Sent: Tuesday, February 19, 2008 06:36
Subject: Re: [BBC-Micro] BASIC error message - "Mis..."?


> Jonathan Graham Harston wrote:
> 
>> BASIC never checks any I/O locations. No language ever checks any
>> I/O locations. It's the Operating System that deals with I/O
>> locations. Any access to I/O locations is done by asking the MOS
>> to do something.
>>  
>> Stop thinking about BASIC interacting with the hardware. It never
>> does. BASIC will function fully and correctly as long as the calls
>> to the entry points at &FFxx do their function.
> 
> I understand that!!! What I meant was that inducing a "Mistake" in BASIC may
> call a MOS ROM routine that does some I/O that is not done during the
> boot-up sequence. I very much doubt that the boot-up sequence accesses and
> checks _every_ bit of _every_ I/O location on the machine, so chances are my
> implementation is lacking in areas that are only exposed when certain
> behaviours are induced, eg 'Mistake', regardless of the fact that the BASIC
> ROM is calling MOS routines to access hardware.
> 
> Trust me, I'm *intimately* familiar with the concepts of OS entry points,
> hardware abstraction layers and platform-independent code...