[BBC-Micro] Screen saving

J.G.Harston jgh at mdfs.net
Wed Aug 1 12:43:29 BST 2012


Tom Pen wrote:
> Is it possible to save the screen on a Master as it was on the model 
> B

You mean *Save screen FFFF3000+5000  ? Exactly the same
as on a BBC model B to save a non-shadow MODE 0/1/2 screen.
Shadow screen memory is at &FFFExxxx, and we had a discussion
here about a year ago about how to transparently always save
the displayed screen on whatever machine is running by
switching in the shadow screen if it is present:
http://mdfs.net/Archive/BBCMicro/2011/04/30/192404.htm

DEFPROCscnsave(A$)
A%=FNfx(108,1):OSCLI "SAVE "+A$+" FFFE3000+5000":A%=FNfx(108,0)
ENDPROC
:
DEFFNfx(A%,X%):LOCAL Y%:Y%=X%DIV256:=((USR&FFF4)AND&FFFF00)DIV256
:
DEFFNerr:A%=FNfx(108,0)
REM Continue error handler

-- 
J.G.Harston - jgh at mdfs.net - mdfs.net




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