rwilson@polya.Stanford.EDU (Randy Wilson) (07/20/88)
I have been writing a Mac video game for some time, and just got around to testing it on system 6.0. When it starts writing to the 2nd graphics screen, it crashes, id=02. It turns out that BufPtr is in the middle of the 2nd screen, so I assume I am trashing info in high memory; it worked on all previous systems. Further, the launch call to allocate the 2nd succeeds, and moves globals, etc down as if clearing the way to use the 2nd, but still dies. I have the Ramcache off and am using no INITs other than the ones in the system as distributed. Does anyone know what Apple has put in high memory? Have they finally made good on their threat to mangle programs that use the 2nd screen? If so, why do they allow the Launch call to succeed, instead of failing there?? Is there a way around this problem? If I can't fix this, I'll have to just tell people to use another version of the system file, unless they're on a II (it works fine there, since it follows all rules on the II). Thanks in advance, Randy rwilson@polya.stanford.edu
dan@Apple.COM (Dan Allen) (07/22/88)
In article <3316@polya.Stanford.EDU> rwilson@polya.Stanford.EDU (Randy Wilson) writes: >I have been writing a Mac video game for some time, and just got around to >testing it on system 6.0. When it starts writing to the 2nd graphics screen, >it crashes, id=02. It turns out that BufPtr is in the middle of the 2nd >screen, so I assume I am trashing info in high memory; it worked on all >previous systems. Further, the launch call to allocate the 2nd succeeds, and > >Does anyone know what Apple has put in high memory? Have they finally made >good on their threat to mangle programs that use the 2nd screen? If so, why This is not a definitive answer, but I believe the problem is related to the Sound Manager. System 6.0 is the first system to backpatch the SM to the Mac Plus and SE. I recall some conflict between sound and the 2nd screen. The Mac II has never supported a 2nd screen, due in part to its having the screen memory located out on a video card and not part of normal user RAM. Perhaps someone else can confirm this hunch. Dan Allen Software Explorer Apple Computer
tecot@Apple.COM (Ed Tecot) (07/24/88)
In article <3316@polya.Stanford.EDU> rwilson@polya.Stanford.EDU (Randy Wilson) writes: >Does anyone know what Apple has put in high memory? Have they finally made >good on their threat to mangle programs that use the 2nd screen? If so, why >do they allow the Launch call to succeed, instead of failing there?? Is >there a way around this problem? This is a known problem with 6.0. It has been fixed for 6.0.1. _emt