[net.micro.mac] Patching Megaroids

tdn@spice.cs.cmu.edu (Thomas Newton) (06/02/86)

Does anyone know how to patch Megaroids properly for the MacPlus?  I tried the
trick of changing sequences of bytes identical to the screen buffer and sound
buffer base addresses, and while the modified Megaroids seemed to run properly,
it always crashed upon exiting with an ID=02.  I then tried leaving two of the
"addresses" alone (those in block two of the resource fork -- they were rather
far away from the others), and the immediate crashes upon quitting went away.
But I am still having problems.  I use a 700-800K RAMdisk produced by RamStart
most of the time, and whenever I run the modified Megaroids, it always seems
to leave the Mac in some weird state (often leading to a system crash).  So my
questions are:

    (1) Which "screen/sound buffer addresses" in Megaroids should be patched
        and which should be left alone (e.g. because they are really code)?
        Is what I am doing now (patching everything but block two) correct?

    (2) Is it safe to use a program that uses the alternate screen buffer when
        using a RAMdisk produced by RAMstart?  I remember reading here that it
        is not safe to use the MacPlus cache with programs that use the second
        screen buffer -- does a similar caution apply to RamStart?

                                        -- Thomas Newton

nathan@orstcs (06/05/86)

Megaroids fix:
Buy the sources from Megamax for $25, and recompile it with the correct
address #defined.  Easy, no? (if you happen to have access to their compiler)
-nathan myers