WHAT KIND OF MEMORY SHOULD I USE IN MY MAC?  (4.1)
--------------------------------------------------

       The easiest way to get this question answered is to ask your 
  friendly, mail-order memory dealer.  If you tell them what model of 
  Mac you have, what memory you already have in your Mac, and how much 
  you want to add, they should be able to tell you exactly what you 
  need.  Memory comes in many configurations.  All desktop Macs from 
  the Plus through the Quadra 700, 900, and 950 use 70 pin SIMMs that 
  normally need to be added four at a time (except in the SE, the Plus 
  and the Classics where they're added two at a time).  Later Quadras, 
  the LC III, and the Centris's use 72 pin SIMMs that can be added one 
  SIMM at a time.  PowerMacs also use 72 pin SIMMs but need  them 
  installed in pairs.  All portable Macs (PowerBooks, Duos, and the 
  Portable) have one RAM slot to hold a special card with extra RAM.
  
       The chart below gives details for each model of Mac.  For each 
  model it lists how much RAM is soldered to the motherboard, how many 
  slots are available to hold more RAM, what size memory is available 
  for those slots, different possible RAM configurations, what type of 
  memory is used (30 pin SIMM, 72 pin SIMM, or card type,) the minimum 
  speed of the RAM you should use in that model, and how many SIMMs or 
  cards need to be replaced or added at the same time.


                              Available  Physical RAM       Minimum Upgrade
     CPU     Onboard  Slots    Sizes    Configs (MB)   Pins  Speed    in

 Plus             0           4     256K,1M    1,2.5,4         30   150ns     2
 SE                0           4     256K,1M    1,2,2.5,4      30   150ns    2
 SE/30          0            8    256K,1M    1,2,4,5,8,16 30   120ns    4
                                          4M,16M    17,20,32,64
                                                           65,68,80,128 
 Classic         1           3    256K,1M    1,2,2.5,4       30   120ns    2
 Classic II      2          2    1M,2M,4M   2,4,6,10        30   120ns    2
 Clr Classic    4          2    1M,2M,4M   4,6,8,10        30   120ns    2
 Mac II            0          8    256K,1M    1,2,4,5,8,17  30   120ns    4
                                        4M,8M,16M  20,33,36,65,68
 Mac IIx          0          8    256K,1M    1,2,4,5,8,16,17 30 120ns    4
                                        4M,8M,16M  20,32,33,36,64
                                                          65,68,80,96,128
 Mac IIcx        0           8    256K,1M    1,2,4,5,8,16,17 30 120ns    4
                                        4M,8M,16M  20,32,33,36,64
                                                           65,68,80,96,128
 Mac IIci         0           8    256K,512K  1,2,3,4,5,6,8   30  80ns     4
                                         1M,4M,8M    16,17,18,20,32
                                          16M             33,34,36,64,65
                                                             66,68,80,96,128
 Mac IIsi        1            4    256K,512K  1,2,3,5,17,33   30  80ns     4
                                         1M,4M,8M     65
                                         16M
 Mac IIvi        4            4    256K,512K  4,5,6,8,20,36   30  80ns     4
                                         1M,4M,8M     36,68
                                         16M 
 Mac IIvx        4           4    256K,512K  4,5,6,8,20,36   30   80ns     4
 (Performa 600)                1M,4M,8M   36,68
                                          16M
 Mac IIfx         0           8    1M,4M,16M  4,8,16,20,32    30  80ns      4
                                           64,68,80,128
 LC                  2           2    1M,2M,4M   2,4,6,8,10         30  120ns    2
 LC II              4           2    1M,2M,4M   4,6,8,10             30   120ns   2
 LC III             4           1    1M,2M,4M   4,5,6,8,12,36     72   80ns     1
                                          8M,16M,32M
 LC 520           4           1    1M,2M,4M   4,5,6,8,12,36     72   80ns     1
                                       8M,16M,32M
 LC 550           4           1    1M,2M,4M   4,5,6,8,12,36     72   80ns     1
                                        8M,16M,32M
 LC 575           4           1    1M,2M,4M   4,5,6,8,12,36     72   80ns     1
                                         8M,16M,32M
 Centris 610    4           2    4M,8M,16M  4,8,12,16,20,24 72   80ns     1
                                           32M            28,36,52,68
 Centris 650    8           4    4M,8M,16M  8,12,16,20,24   72   80ns     1
                                           32M            32,40,68,72,132
 Centris 660av  4          2    4M,8M,16M  4,8,12,16,20,24 72  70ns     1
                                           32M             28,36,52,68
 Quadra 605      4          1    4M,8M,16M  4,8,12,20,36    72   80ns     1
                                             32M
 Quadra 610      4          2    4M,8M,16M  4,8,12,16,20,24 72  80ns     1
                                            32M           28,36,52,68
 Quadra 650      8           4    4M,8M,16M  8,12,16,20,24   72   80ns     1
                                            32M             32,40,68,72,132
 Quadra 660av   4           2    4M,8M,16M  4,8,12,16,20,24 72   70ns     1
                                             32M            28,36,52,68
 Quadra 700      4           4    1M,4M,16M  4,8,20,68           30   80ns     4
 Quadra 800      8           4    4M,8M,16M  8,12,16,20,24   72   60ns     1
                                             32M        28,32,36,40,44
                                                            48,52,56,60,64
                                                             68,72,80,84,88
                                                         104,108,112,120,132
 Quadra 840av    0          4    4M,8M,16M  8,12,16,20,24   72   60ns     1
                                             32M        28,32,36,40,44,48,52,56
                                                           60,64,68,72,76,80,84,88
                                                           96,100,104,112,128
 Quadra 900        0        16   1M,4M,16M  4,8,12,16,20    30   80ns     4
                                                             24,28,32,36,40,48,52,64
                                                             64,68,72,76,80,84,88,96
                                                            100,112,128,132,136,144
                                                            148,160,192,196,208,256
 Quadra 950        0        16    1M,4M,16M  4,8,12,16,20    30   80ns     4
                                                        24,28,32,36,40,48,52,64
                                                        64,68,72,76,80,84,88,96
                                                       100,112,128,132,136,144
                                                       148,160,192,196,208,256
 PowerMac 6100  8       2      4M,8M,16M  8,16,24,40,68   72   80ns     2
                                             32M
 PowerMac 7100  8       4    4M,8M,16M  8,16,24,32,40     72   80ns     2
                                           32M            48,56,72,80,88
                                                             104,132
 PowerMac 8100  8       8    4M,8M,16M  8,16,24,32,40   72   80ns     2
                                           32M          48,56,64,72,80,88
                                                            96,104,112,120,128
                                                            136,144,152,160,168
                                                          176,184,208,216,232,264

 Portable              1       1    1M,2M,3M,4M 1,2,3,4,5          100ns     1
 PowerBook 100   2       1    2M,4M,6M    2,4,6,8       TSOP 100ns     1
 PowerBook 140   2       1    2M,4M,6M    2,4,6,8       TSOP 100ns     1
 PowerBook 145   2       1    2M,4M,6M    2,4,6,8       TSOP 100ns     1
 PowerBook 145b 4       1    2M,4M       4,6,8             TSOP 100ns     1
 PowerBook 160   4       1    4M,6M,8M    4,8,10,12    TSOP  85ns     1
                                              10M         14
 PowerBook 165c 4       1    4M,6M,8M    4,8,10,12     TSOP  85ns     1
                                           10M         14
 PowerBook 170  2       1    2M,4M,6M    2,4,6,8           TSOP 100ns     1
 PowerBook 180  4       1    4M,6M,8M    4,8,10,12       TSOP  85ns     1
                                          10M         14
 PowerBook 180c 4       1    4M,6M,8M    4,8,10,12      TSOP  85ns     1
                                             10M         14
 Duo 210        4       1    4M,8M,10M   4,8,12,14,16        85ns     1
                                      12M,14M     18,24,32
                                       20M,28M
 Duo 230        4       1    4M,8M,10M   4,8,12,14,16        85ns     1
                                     12M,14M     18,24,32
                                      20M,28M
 Duo 250        4       1    4M,8M,10M   4,8,12,14,16        85ns     1
                                      12M,14M     18,24,32
                                       20M,28M
 Duo 270c       4       1    4M,8M,10M   4,8,12,14,16        85ns     1
                                      12M,14M     18,24,32
                                                          20M,28M

	The Mac Classic requires an adapter card to expand the RAM from 
  1 MB.  This card includes 1 MB of extra memory and has two SIMM 
  slots that can either be left empty or filled with 256K or 1MB 
  SIMMs.  The slots must be filled with the same size SIMM.

       The Color Classic, LC, and LC II can only address 10 megabytes 
  of real RAM even if twelve megabytes of physical RAM are installed.

       The Mac II requires the addition of a PMMU chip to access more 
  than eight megs of RAM.  The first bank can only hold 256K or 1MB 
  SIMMs unless the FDHD upgrade is installed.  Otherwise 4, 8, and 16 
  MB SIMMs have to be installed in Bank B.  Furthermore these SIMMs 
  need an extra PAL chip on each SIMM as well as the normal eight DRAM 
  chips.

       The Quadra 700 requires non-composite, low-profile 16 megabyte 
  SIMMs to fit under the internal hard drive.  Composite SIMMs should 
  also not be used on 68040 AV Macs as they are practically guaranteed 
  to cause problems with the system due to the extra load and timing 
  required.  Specifically you need to avoid 16MB SIMMs that use 32 
  4M-bit DRAMs rather than 8 16M-bit DRAMs. 

       PowerBooks use pseudo-static thin small-outline package cards 
  (TSOP's) of varying capacities.  Duo's use special low-power, 
  self-refreshing dynamic RAM cards.  Be sure to specify the model 
  you're ordering for when buying PowerBook RAM.