[comp.sys.mac.programmer] Alternate video buffer for Mac Plus

sje@cs.nott.ac.uk (Stephen J Eglen) (03/02/91)

Dear All
I am having problems with storing bit images in the area designated for the
alternate video buffer on the Mac Plus.  I can switch to the alternate video
buffer ( I think) by using BCLR #6,0xeffffe, but it never seems to display my
images that should have been loaded into that area.  I think that maybe :
1. I am using the wrong assembler code, embedded in c ( on the THINK C package)

2  The memory pointed to by BufPtr is not allocated for the alternate screen
display.
or 3. I am doing sth. really wrong!

Can aanyone who knows how to switch between  two bit images using the two buffer
s please get in contact with this (inexperienced) mac programmer, who despeartel
y needs help!

If you can help me, please e-mail me as sje@Cs.Nott.AC.UK

 Thank you very much!
			Stephen Eglen  ( year 2 undergrad at Nottingham Univ)