Skip to main content
Home Forums Maximum RAM Addressing in 24-bit Mode Maximum RAM Addressing in 24-bit Mode
Thread

Maximum RAM Addressing in 24-bit Mode

Maximum RAM Addressing in 24-bit Mode Hardware 4 posts Sep 28, 2007 — Sep 29, 2007
What is the max amount of RAM that can be addressed my Macs with so-called "Dirty ROMs" without using something like MODE32? I always thought that it was eight megs, but when my Classic II is booted in 24-bit mode, it sees all 10 megs that are on there. Any ideas?

I believe it is 8MB and that the Classic II has 32 bit addressing. If I'm not mistaken, the Classic II will not run anything earlier than System 7, save a special version of 6.08.

Does your System heap use 2 MB more when in 24-bit addressing mode than it does when in 32-bit?

Without enabling 32-bit addressing, the Mac OS only has access to 8 MB of memory. Anything beyond that is reported as used by the system.
http://lowendmac.com/trouble/32bit.shtml

Does your System heap use 2 MB more when in 24-bit addressing mode than it does when in 32-bit?
Without enabling 32-bit addressing, the Mac OS only has access to 8 MB of memory. Anything beyond that is reported as used by the system.
http://lowendmac.com/trouble/32bit.shtml
Ooooo, I'll have to check that. I'll report back when I do. Thanks for the tip!

mp.ls