LC 

Physical Memory: The SIMM bank may either be empty, or
 filled with two SIMMs, which must be of the same size. The 
LC does not support 256K or 512K SIMMs. Only memory 
configurations of 2, 4, 6, 10MB are possible.  The ROMs 
support standard 32–bit addressing, but are configured to 
support a maximum of 10MB of RAM. To address over 
8MB (10MB) you must either use System 7 32–bit 
addressing or System 6 and OPTIMA. Because there is no 
support for a PMMU, MAXIMA cannot be used. The LC is not 
a good choice for large memory applications.

Extended Memory: Only possible if you add a 68030  or 
68040 accelerator. The LC is based on the 68020 CPU (see 
“Mac II Virtual Memory”) but has no socket to hold a PMMU. 
Accelerated LCs are usually limited to 10MB virtual memory, but at least one third party accelerator card can remove this 10MB limitation.

Video RAM:  LCs shipped after May 13, 1991 have 512K of VRAM installed, enough to address 8–bit color on a 13" monitor.  On earlier LCs, 256K of 68–pin video RAM is factory–installed in the single SIMM socket which is enough to support 4–bit color on a 13" monitor. Many people remove it to put in a third party 512K SIMM. The 256K SIMM that is removed can be used as expansion video RAM on a Quadra. 

LC II 

Physical Memory: The SIMM bank may either be empty, or 
filled with two SIMMs, which must be of the same size. The 
machines do not support 256K or 512K SIMMs. 24-bit mode 
memory configurations of 4 or 6MB are possible. The ROMs 
support standard 32–bit addressing, but are specially 
configured to support a maximum of 10MB of RAM. To 
address large amounts of RAM, use System 7 standard 
32–bit addressing. The LC II can use standard 4MB SIMMs, 
but will not address more memory than 10MB.

Extended Memory: The 68030 CPU in the LC II has a built–in 
Memory Management Unit. Therefore, it can run RAM 
Doubler or virtual memory without additional hardware. In 
24–bit mode the LC II can use up to 14MB of Connectix 
Virtual, or 13MB of System 7 VM. In 32–bit mode the LC II can 
use up to 1024 MB of virtual memory (or the amount of available hard drive space.) When performance is critical, or hard drive space is limited, we recommend RAM Doubler.

Video RAM: There are two versions of the LC II. The LC II with a 40MB hard drive comes with 256K of 68–pin video RAM factory–installed in the single SIMM socket. This is enough to support 4–bit color on a 13" monitor. Many people remove it to put in a third party 512K SIMM, so that the LC II can address 8–bit color on a 13" monitor. The 256K SIMM that is removed can be used as expansion video RAM on a Quadra. The LC II with a 80MB hard drivehave 512K installed already.
Performa VRAM is installed on-board, with 1 additional VRAM SIMM slot.  Performa 400: 256K installed, 512K maximum. 405, 410: 512K maximum installed. 430: 512K installed; 768K maximum

LC III 

Physical Memory: The SIMM bank may either be empty, or
 filled with one SIMM. The LC III uses a 72-pin SIMM that is 
different from the standard used in the original LC model. 
24-bit mode configurations of 4, 5, 6, or 8MB are possible. To 
address large amounts of RAM, use System 7 standard 
32–bit addressing. The SIMM slot also accepts a 8, 16, or 
32MB SIMM, for a maximum of 36MB.

Extended Memory: The 68030 CPU in the LC III has a built–
in Memory Management Unit. Therefore, it can run RAM 
Doubler or virtual memory without additional hardware. In 
24–bit mode the LC III can use up to 14MB of Connectix 
Virtual, or 13MB of System 7 VM. In 32–bit mode it can use 
up to 1024 MB of virtual memory (or the amount of available 
hard drive space.) When performance is critical, or hard drive 
space is limited, we recommend RAM Doubler.

Video RAM: 512K soldered on. One expansion slot is available for a maximum of 768K video RAM. 

LC 475 
Physical Memory: The bank may either be empty, or filled 
with one SIMM. Memory configurations of 4, 5, 8, 12, 20, and 
36MB are possible. To address large amounts of RAM, use 
System 7 standard 32–bit addressing.

Extended Memory: The 68040 CPU in the LC 475 has a built–
in Memory Management Unit. Therefore, it can run RAM 
Doubler or virtual memory without requiring any additional 
hardware. In 24–bit mode, the 475 can address up to 13MB 
of VM, and in 32–bit mode, it can address up to 1024MB. In 
situations where performance is critical, or hard drive space 
is limited, we recommend RAM Doubler. 

Video RAM: Two VRAM banks of one slot each. In the 
standard configuration, one of the banks has 512K of 68–pin 
VRAM installed in it. The 475 only supports 80ns 512K VRAM SIMMs.

LC 520, 550 
Physical Memory: These machines use a 72-pin SIMM that is 
different from the standard used in the original LC model. 
24-bit mode memory configurations of 4, 5, 6, or 8MB are 
possible. The SIMM slot also accepts a 8, 16, or 32MB SIMM. 
To address large amounts of RAM, use System 7 standard 
32–bit addressing.

Extended Memory: The 68030 CPU in these machines has a 
built–in Memory Management Unit. Therefore, it can run 
RAM Doubler or virtual memory without additional hardware. 
In 24–bit mode these machines can use up to 14MB of 
Connectix Virtual, or 13MB of System 7 VM. In 32–bit mode 
it can use up to 1024 MB of virtual memory (or the amount of 
available hard drive space.) When performance is critical, or 
hard drive space is limited, we recommend RAM Doubler.

Video RAM: 512K video RAM is installed, 1 slot expandable to 768K. 

LC 575 
Physical Memory: The 575 uses a 72-pin SIMM that is 
different from the standard used in the original LC model. 
24-bit mode memory configurations of 4, 5, 6, or 8MB are 
possible. The SIMM slot also accepts a 8, 16, or 32MB SIMM. 
To address large amounts of RAM, use System 7 standard 
32–bit addressing.

Extended Memory: The 68040 CPU in this machine has a 
built–in Memory Management Unit. Therefore, the 575 can 
run RAM Doubler or virtual memory without additional 
hardware. In 24–bit mode the 575 can use up to 14MB of 
Connectix Virtual, or 13MB of System 7 VM. In 32–bit mode 
the 575 can use up to 1024 MB of virtual memory (or the 
amount of available hard drive space.) When performance is 
critical, or hard drive space is limited, we recommend RAM 
Doubler.

Video RAM: 512K video RAM is installed, 1 slot expandable to 1MB. 

LC 630 
Physical Memory: The 630 uses a 72-pin SIMM that is 
different from the standard used in the original LC model. 
24-bit mode memory configurations of 4, 5, 6, or 8MB are 
possible. The SIMM slot also accepts a 8, 16, or 32MB SIMM. 
To address large amounts of RAM, use System 7 standard 
32–bit addressing.

Extended Memory: The 68040 CPU in this machine has a 
built–in Memory Management Unit. Therefore, the 630 can 
run RAM Doubler or virtual memory without additional 
hardware. In 24–bit mode the 630 can use up to 14MB of 
Connectix Virtual, or 13MB of System 7 VM. In 32–bit mode 
the 630 can use up to 1024 MB of virtual memory (or the 
amount of available hard drive space.) When performance is 
critical, or hard drive space is limited, we recommend RAM 
Doubler.

Video RAM: 1 MB of 80ns video DRAM is installed, which can support 16-bit color on a 14" monitor.