Acorn BBC Master 65C102, User Manual

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program from disc, you would type:
*RUN GRAFPRG <RETURN>
The program would be loaded back into the co-processor rather than
the I/O processor (no leading 'FFFFs' in the load address and end
address), and would run.
To save the resulting picture onto disc, you would have to save the
screen memory used in MODE 1, this resides in the I/O processor.
MODE 1 screen memory starts at &FFFF3000 and ends at &FFFF7FFF (ie
memory locations &3000 to &7FFF in the I/O processor). To save the
resulting picture, you would type:
*SAVE PICTURE F5000 <RETURN>
where PICTURE is the filename you have chosen. If you now reload
this by typing:
*LOAD PICTURE <RETURN>
the file PICTURE will be loaded into the I/O processor, and as long as
you are already in MODE 1, the picture will reappear. (From this you
can probably deduce why some programs that directly access the screen
will not work with the co-processor.)
Note: It is not possible to save a shadow screen in this way. To save
or load a shadow screen you must make use of either the OSWORD calls
&5 and &6, or the *FX114 command to 'switch' SHADOW RAM into the main
memory map. For further information, please refer to the REFERENCE
GUIDE.
You may have noticed that when you execute a *INFO on a disc file,
addresses are preceded by either 00 or FF, rather than 0000 and FFFF.
For example typing:
*INFO PICTURE <RETURN>
might display
$.PICTURE FF3000 FF3000 FF4FFF 07A
and typing
*INFO GRAFPRG <RETURN>
might display
$.GRAFPRG 006000 006000 000500 05B
The disc filing system ignores the two most significant bytes of the
addressing, the cassette filing system displays the addressing in
full.
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