[Coco] DECB DOS Command

[John E. Malmberg]

tim lindner wrote:
> I was just reading the Disk BASIC unravelled book and came away with the
> following question:
> 
> Why does the 'DOS' command first issue a SWI3 instruction?
> 
> Disk BASIC sets up the SWI3 vector to do nothing. It just returns to the
> caller. 

Well I do not know what it was intended for, but when I know of several 
things that it could be used for.

While it may be difficult to get ROM BASIC to work under OS-9, it is 
relatively trivial to get it to work under FLEX+.

The major issue when doing that is that to exit back to FLEX, you had to 
EXEC back to the right location.  The DOS command would allow a warm start.

So this feature can be very useful, if you want to use the DOS command 
to load something other than OS-9 that can run DECB, and wants to do a 
warm start.

-John
wb8tyw at qsl.network
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