Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 UW 5/3/83; site uw-beaver Path: utzoo!watmath!clyde!bonnie!akgua!whuxlm!whuxl!houxm!vax135!cornell!uw-beaver!info-mac From: info-mac@uw-beaver (info-mac) Newsgroups: fa.info-mac Subject: FatMac memory map? Message-ID: <2392@uw-beaver> Date: Sat, 1-Dec-84 07:30:09 EST Article-I.D.: uw-beave.2392 Posted: Sat Dec 1 07:30:09 1984 Date-Received: Tue, 4-Dec-84 06:34:41 EST Sender: daemon@uw-beave Organization: U of Washington Computer Science Lines: 27 From: David.Anderson@CMU-CS-K.ARPA I would like to construct an environment on my FatMac that looks exactly like a 128K machine for testing out applications that I write distributing them. Has anyone figured out how to do this? I know that the screen and sound buffers are shifted up by $60000, but I've been peeking around in memory to find out what else is different. The only other difference that I see is that the system heap extends from $B00 to $CB00, for a total of 48K bytes, vs. only 16.5K on the smaller Mac. Why and how is this done? My guess is that this is probably done by one of the 3 original INIT resources in the system -- anyone know for sure? Another point of concern is the RamDisk -- I wonder if I've found a bug. The INIT 3 resource slides BufPtr down to $28000, and I see in the RamDisk sources that it occupies $50000 bytes, or out to $78000. However, when running without the RamDisk, but with MacsBug, BufPtr is $76640. It appears to me that if you fill up the RamDisk you'll overwrite part of the debugger. P.S. I've found that many of the PD programs I have don't work on my FatMac -- dbrothers' music engine, the Clock with numbers that transform before your eyes, and others. (And I found out the hard way; I offered to have my Mac play some music for a guest, and after waiting for it to initialize the waveforms, etc., out came nothing.) If you do your own screen or sound hacking, make sure to use the $7a700 and $7fd00 addresses -- they'll map around on a 128K Mac.