bhyde@inmet.UUCP (02/13/86)
I believe that the Megamax problem described in this string applies only to desk toys. Megamax choose to dedicte register A4 to point to the globals of the C program. If you want to write a desk toy which has vanilla C globals then they have to find a way to get A4 set up for you as you slip in and out of the toy. No such problem exists for more typical applications. Demonstrating the problem is more difficult than just writting a desk toy, you have to have the need time polling of the toy turning on. There are a similar class of problems when you write menu def procs or CDEFs, i.e. the A4 globals pointer will be "broken" and you can't get to quickdraw's globals, such as: gray, screenBits, etc. In the other more unusual CODE resources Megamax makes no particular attempt to support globals. I'd be interested if anybody knows exactly why they couldn't arrange to get the globals accessed of A5? - ben hyde, cambridge.
brad@gcc-milo.ARPA (Brad Parker) (02/15/86)
In article <26700052@inmet.UUCP> bhyde@inmet.UUCP writes: >... If you want to write a desk toy >which has vanilla C globals then they have to find a way to get A4 >set up for you as you slip in and out of the toy. No such problem >exists for more typical applications. > - ben hyde, cambridge. The MegaMax DA wrap "ACC()" calls routines which set up and tear down A4 automagically. You really don't have to worry about it in a DA (as long as you don't use "needtime"). -- J Bradford Parker General Computer (HyperDrive Beach) harvard!gcc-milo!brad "She said, 'Just drive.'" -heard on the radio.