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more memory than designed on a Performa 460 (LC3+)
- Thread starter Dj Mike
- Start date
GiGaBiTe
Veteran Member
The maximum amount of memory that can be installed in an LC III / LC III+ / Whatever else Apple stuffed that logic board in is 36 MB. 4 MB onboard and a single 32 MB SIMM. The logic board does not support 64 or 128 MB SIMMs due to lack of address lines. If such a module is installed, the machine either won't boot or will show 32 MB or less, depending on the topology of the module.
36 MB of RAM was more than enough memory for this logic board, if you need more than that, you're probably exceeding the processing capabilities of the CPU. You can use RAM Doubler 9 to increase the amount of memory via compression and virtual memory, but it will considerably slow the machine down.
36 MB of RAM was more than enough memory for this logic board, if you need more than that, you're probably exceeding the processing capabilities of the CPU. You can use RAM Doubler 9 to increase the amount of memory via compression and virtual memory, but it will considerably slow the machine down.
I’ve seen a few people mod lc3 and lc3+ with up to 128. Megs …
36megs does not seem like much but as you have said 36 should be way more than enough for a 1993 machine. After maxing out the ram on my Intel Mac pros to 32 and 64gigs I’m prone to go as high as possible on ram since I don’t like the idea of sluggish lag while multitasking apps. I need to remember the 68k machines were never designed for true multitasking… since at this point the 68k machines are more experimental and show pieces in my basement I’ll probably just leave it at 36meg.
36megs does not seem like much but as you have said 36 should be way more than enough for a 1993 machine. After maxing out the ram on my Intel Mac pros to 32 and 64gigs I’m prone to go as high as possible on ram since I don’t like the idea of sluggish lag while multitasking apps. I need to remember the 68k machines were never designed for true multitasking… since at this point the 68k machines are more experimental and show pieces in my basement I’ll probably just leave it at 36meg.
People most likely do such mods to brag about. It just does not make much sense. It only has a 030, so it is quite limited in running "heavy" software anyway.
Use it the way it was designed, as that's the whole point of keeping these systems alive.
Use it the way it was designed, as that's the whole point of keeping these systems alive.
GiGaBiTe
Veteran Member
Yeah, no. Never happened, if someone said they did it, they're lying. The absolute maximum memory that can be installed in an LC III is 68 MB, but this requires either significant hardware modding, or a special SIMM module with two additional connections to the logic board for extra RAS/CAS lines. Theoretically, if you could figure out where the hard coded bank 0 limit is (the 4 MB onboard) in the system ROM, with additional hardware hacking, it would be possible to get up to 80 MB (16 MB + 32 MB + 32 MB.)
Breaking the 36MB RAM limit on the LCIII
Normally the LCIII is limited to 36MB of RAM - 4MB onboard and one 32MB SIMM The simms are limited to 32MB as there are only 11 address lines hooked up to the RAM SIMM socked so larger sticks won't work (The will typically show up as 16 or 32MB) However while creating a pin listing for the...
tinkerdifferent.com
With 68 MB, the machine would take a long time to even get to the boot screen due to the memory test. My Quadra 605 with a 33 MHz 68040 takes 30-45 seconds to even show the boot screen with 68 MB of RAM. A 68030 is going to take even longer.