[BBC-Micro] Scrolling scrolling scrolling...

Tom Seddon tom at tomseddon.plus.com
Thu Dec 7 20:24:05 GMT 2006


On a Beeb, ?&D0=2 (from memory) stops the screen scrolling when you get 
to the bottom right. The cursor just runs back to the top left again.

AUG says this location is controlled by OSBYTE &75 so you should 
probably use that method instead ;)

--Tom

Ian Wolstenholme wrote:
> Yes, I was trying to avoid use of VDU 5 which is the
> straightforward way of doing it.
> 
> Unfortunately plan B doesn't work on the BBC B
> or on the Master with SCROLL configured, so I am
> working on plan C!
> 
> This only works on the Master as it uses VDU23,16
> to control cursor movement which doesn't appear to
> be implemented on the BBC B:
> 
> 10MODE 1
> 20VDU23,16,32;0;0;0;
> 30PRINTTAB(39,31)"*";
> 40PRINTTAB(0,0)
> 50VDU23,16,0;0;0;0;
> 
> Best wishes,
> 
> 
> 
> Ian
> 
> ----- Original Message -----
> From: Richard Gellman [mailto:splodge at starfleet.homeunix.net]
> To: bbc-micro at lists.cloud9.co.uk
> Sent: Wed, 06 Dec 2006 22:32:38 +0000
> Subject: Re: [BBC-Micro] Scrolling scrolling scrolling...
> 
> Steve Fewell wrote:
>> --- Ian Wolstenholme <BBCMailingList at beebmaster.co.uk>
>> wrote:
>>
>>   
>>> An alternative to my earlier solution, which should
>>> work on
>>> a BBC B although I have only tried it on the Master,
>>> is to
>>> define a single-character text window at (39,31):
>>>
>>> 10 MODE 1
>>> 20 VDU 28,39,31,39,31
>>> 30 PRINT"*";
>>> 40 VDU 26
>>>
>>>     
>> Another alternative is to use graphics cursor mode
>> (VDU 5):
>>   
> Unfortunately Dom did say without using VDU 5 :)
> 
> I'm sure I saw somewhere as OSBYTE/*FX call that set scroll/no-scroll, 
> but having gone thru the AUG thrice, I cannae find it cap'n.
> 
> There is a sneaky way to do it in MODE 7, but its not ideal and probably 
> won't work if you've already scrolled the screen:
> 
> ?&7FE7 = <character>
> 
> I believe the Acorn parlance for such a trick is "illegal programming" :)
> 
> -- Richard
> 
> _______________________________________________
> bbc-micro mailing list
> bbc-micro at lists.cloud9.co.uk
> http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro
> 
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> bbc-micro mailing list
> bbc-micro at lists.cloud9.co.uk
> http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro
> 
> 
> ------------------------------------------------------------------------
> 
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.409 / Virus Database: 268.15.15/579 - Release Date: 07/12/2006
> 




More information about the bbc-micro mailing list