[BBC-Micro] TUBE code in the Master

David Harper dl.harper at btopenworld.com
Mon Mar 3 22:15:11 GMT 2008


Sprow wrote:

>> If you *UNPLUG F, then you will find you cannot use the Tube.
>
> Yes you can.
>
> Unplugging the respective filing system on a B/B+ stops the Tube from
> working because there's noone listening for the service call which prompts
> the Tube initialisation.
>
> On the Master unplugging Terminal has no effect as the code for *FX143
> always calls ROM 15 regardless of its status: the bulk of the Terminal
> service code is mainly used for the Tube and some cassette filing system
> stuff.

You may well be right here. I don't have a machine handy to check at 
present.

Some of the stuff in ROM bank &F is used on reset to set everything up. I 
did a disassembly of the Master's reset sequence at one stage, and I 
remember most of the code being here. With OS 3.20 (the standard Master 
ROM), at an early stage after Break (or power-up) this bank is entered at 
location &8020 and execution continues through until about location &8346 
before jumping back into the top section of the ROM (to location &E40E).

David Harper 




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