tsai@Veritas.COM (Cary Tsai) (01/14/91)
I plan to buy a Mac classic with 2M bytes memory and 40M disk. I am wondering that I can buy another 2M bytes memory for that little machine. I read an article from a Mac magazine saying that Mac classics only can have 2.5 Mega bytes memory at most. Is that a correct statement. I am a mainframe, mini, unix, pc-dos person. I only know Mac a little bit. I was surprised by Mac OS and HyperCard/HyperTalk 2 weeks ago, although I worte programs for more than 10 years. The primary reason to buy Mac is to learn HyperCard/HyperTalk and some personal stuffs. After I knew Mac more , I prefer to use Mac rather than Window 3 at home. Any info would be appreciated. And long life to Mac.(I wish)
sam@wolfen.cc.uow.oz (Sam Tan) (01/14/91)
This is the memory layout in a Classic: There is 1 MB of RAM soldered on the mother board. Apple sell a memory expansion card that has 1 MB soldered on there, but with 2 empty SIMM slots. You can put it anything you want in the SIMM slots but you must do it in pairs. You can only go up to 8 MB on a Classic, although the ROM is 32-bit clean. This is due to the lack of a true PMMU system. In closing, you can put it anything you want into the SIMM slots but you will only see the first 8 MB. You can get INITs that will let you access more than 8 MB, but not more than 8 MB at a time, ie. use MultiFinder and each application can only see 8 MB. Enjoy! sam@wolfen.cc.uow.edu.au
bdugan@teri.bio.uci.edu (Bill Dugan) (01/14/91)
In article <6730@wolfen.cc.uow.oz> sam@wolfen.cc.uow.oz (Sam Tan) writes: >This is the memory layout in a Classic: > >There is 1 MB of RAM soldered on the mother board. > >Apple sell a memory expansion card that has 1 MB soldered on there, but >with 2 empty SIMM slots. You can put it anything you want in the SIMM slots >but you must do it in pairs. You can only go up to 8 MB on a Classic, although >the ROM is 32-bit clean. This is due to the lack of a true PMMU system. This is not true! The Mac Classic can only have 4 megs of RAM, same as a Plus or SE. And the PMMU's presence or absence doesn't have anything to do with the arbitrary eight-meg limit on the Mac II line; the problem came from the memory layout Apple 'decided to have' when they wrote the ROMs in the first place. System 7 will let you have up to 128 Mb of directly addressed RAM, and this is not dependent on a PMMU. bill