PS/2 Memory Reference

PS/2 SIMM-Memory SYSTEM-BOARD Matrix
Type
Mod.
Mod.
Mod.
Mod.
#
#
#
#
#
#
#
#
8590 XP 085       06 07            
8590 XP 0H5 0H9     14 15 16 22 23 24    
8590 XP 0G5 0G9 0JX 0KX 06 07 14 15 16 22 23 24
8590 XP 0MX       25 26            
8595 XP 0H9 0HF     14 15 16 22 23 24    
8595 XP 0G9 0GF 0JX 0KX 06 07 14 15 16 22 23 24
8595 XP 0MX       25 26            
8642         71 72            
9585  0X6 0XA 0XF   06 07 14 15 16 22 23 24
9595 P         22 38 39          
9595 ECC         25 26 46          
# - Reference / Memory Specifications


      3 2 1 0

For more details see Memory-Presence Determination
NOTE: "X" is ground
NOTE:  ECC has pin 48 connected to ground. Parity leaves pin 48 open.
#
Type
FRU P/N
MFG P/N
OPT P/N
Size
ns
Key
 3 2 1 0
06
P
90X8624 68X6065
68X6245
65X6264
23F9173
23F9233
6450603
1M
85
X..X
07
P
92F0104 68X6127
4195816
6450604
65X1309
65X5804
65X6170
65X6197
65X6249
0701600
65X2429
82F5506
6450604
92G7196
2M
85
X.X.
14
P
92F0103
15F7658
65F5806
65X6198
65X5806
6450608
2M
80
.XX.
15
P
92F3337 68X6343
63X6384
87F9977
92G7199
4M
80
XXXX
16
P
64F3607 68X6344 6450129
92G7428
8M
80
.XXX
22
P
92F0102
64F3604
71F7008
87F5041
6450902
92G7198
2M
70
..XX
23
P
92F0105 71F7010
64F3605
31F2314
40G6055
78G9176
6450128
92G7200
4M
70
X.XX
24
P
64F3606 71F7011
78G9177
6450130
92G7202
8M
70
.X..
25
ECC
92F0097 42G3072 6451158
4M
70
X.XX
26
ECC
92F0098 42G3073
74G1105
6451159
92F7208
8M
70
.X..
38
High-Rel.
71G6203    
4M
70
X.XX
39
High-Rel.
71G6204    
8M
70
.X..

ECC
92F0098

92G7208
8M
70
..X.
46
ECC
96F9100 42G3237 92G7209
16M
70
.X.X
71
ECC
06H7761    
16M
60
 

ECC
96G9100
05H0909
16M


72
ECC
06H7762   92G2941
32M
60
 

In the case of the 16MB ECC IBM uses the pins 69 & 67 tied against 72 (GND) to recognize it as 16MB / 70ns ECC ... which is accidently the same coding as for the 16MB / 70ns Parity. Unlike to that the ECC-SIMM has pin 48 tied to GND as well - the Parity and Non-Parity modules have this pin not connected. 

8MB has 69 tied to ground.

Usually the 32MB / 70ns SIMMs use the PD-pattern 70 & 67 open, 68 & 69 closed (GND). The ECC / Non-ECC determination is pin 48 on the module, which is open on Non-Parity and Parity and GND on ECC modules. So from the presence-detect part of the story 60ns modules *could* be reworked.

The problem is the level of integration of the ECC on the module. The "original" IBM ECC-modules are 40-bit modules: 32 (4 x 8) data bits, 4 x 1 ECC-bits, 4 x 1 spare bits. The ECC-logic is part of the system board. There are different ECC structures, which use 36-bit memory (parity) and a particular signalling if the memory integrity is void, there are modules with lesser bits per module (38 or 39) and modules with "ECC On SIMM" (EOS), which have the ECC-logic on the module and the sysboard "thinks" they were Parity modules. There is only a logic signal present that signals a failing module to the sysboard logic in case a correctable ECC-error occured. (In case of a non-correctable ECC-error you land on a memory error anyway).

However I don't (yet) know which coding they use. 32MB Parity and 32MB Non-Parity use 67 & 70 open, 68 & 69 shortened to 72 (GND). Most likely this same pattern applies to the 32MB ECC as well.

OEM-Memory (Substitute VENDOR SIMMs) Specification
(for details see also above reference-list and same # )
#
Type
FRU P/N
OEM Number
Size
ns
07
P
92F0104 MNB36512S85
THM365120S-85
MSC2321-85YS18A
HB56D512361B-8
1600A53R1466
9011HCK
9011HAK
365120AFG
TC514256A
TC51256T 80
MN4B36512S85
MN41C42565J
MNSC2321-85YS18A
2MB
85
14
P
92F0103 A25069180
2MB
80
16
P
64F3607 MSC2351-8AYS24AIB-7
8MB
80
22
P
92F0102 THM365120ASG-70
HM365120ASG-70
KMM536512BG-7
MSC2321-70YSI6A
2MB
70
23
P
92F0105 94-VOHB56D00136IB-7
4MB
70

E
92F0098 KTM1159
8MB
70

E
96G9100 MSC23439-7CBS10A
16MB

OEM-Memory Modules Specification (by Manufacturer)
Type ID, OEM P/2 FRU
Kingston
8 MB ECC KTM1159  
16 MB ECC KTM3720  
32 MB ECC KTM9595  
Viking
8 MB ECC I1159 92G7208
16 MB ECC I3720 92G7209
32 MB ECC I7210 92G7210
4 MB ? I128 92G7200
8 MB ? I130 92G7203
Mcglen Micro (Viking Components)
16 MB ECC DP16I3720  
32 MB ECC DP32I7210   
2 MB ? DP2I902  
4 MB ? DP4I128  
8 MB ? DP8I130  
PNY Has only the Lacuna-76 / -77 in their current list, but the 4/8/16MB modules from the PS/VP-2 should fit in there.
4 MB / 70 ns P P-92G7201  (no longer available)
8 MB / 70 ns P P-92G7204  (no longer available)
16 MB / 70 ns P P-92G7204  IBM 92G7204 / 60G2950
PIICEON
4 MB / 70 ns P 907-0345  IBM 92G7200
8MB/70n P 900-0070  IBM 92G7203
16 MB / 70 ns P 907-0716 under PS/VP IBM 92G7204 / 60G1622
8 MB ECC 907-9508 2 x IBM 6451158 / 4MB
16 MB ECC 907-9516 2 x IBM 6451159 / 8MB
TRANSCEND
2 MB / 70 ns P TS2M0902 IBM 6540902
4 MB / 70 ns P TS4M0128 IBM 6540128 / 92G7200 / 70G9820
8 MB / 70 ns P TS8M0130 IBM 6540130 / 92G7203 / 070PS8Y
16 MB / 70 ns P
8 MB ECC TS8M1159 IBM 6541159
16 MB ECC TS16M3720 IBM 32G3720
32 MB ECC TS32M7210 IBM 92G7210 / 070E32Y

Memory-Presence Determination

SIMMs that are not clearly labeled cannot be identified other than by part number. 

(For MEMORY component define, you will have the need to know about 70 or more timing/temperature parameters. Because this information will not fit on a SIMM normally only P/N / Speed and Size is printed on a small Label). 

SIMM Identification (Single Inline Memory Module) 
72-pin memory SIMMs are usually marked with a label that shows the size and speed (e.g. 1Mx32, 60ns). To determine the SIMM capacity from the above example, divide 32-bits by 8 (1-byte) and multiply this result by 1M, hence, SIMM = 4MB (SIMMs prefix -6R = RAS max. 60ns and Reduced CAS-timing (-2ns) appr. CAS = 19ns) 
XMx32 is Non parity  and XMx36 is Parity

PS/2 72-Pin SIMMs (for M/T 85xx/95xx) 
A set of 4-Bits shows the state of the presence detect signals for a specific memory connector. The setting of the presence-detect bits is determined through registers (x'00E8' and x'00E9'). 

Not all of the following Memory-modules are supported by every IBM computer.


Pin 72 to Pin 70, 69, 68 and 67 ( X = connected to GND) 

Presence-Detect Bits table
Bits.
3 2 1 0
Measure
-ment
Single Inline Memory - Module Definition
1101
..X.
32MB 60-ns Industry standard
1001
.XX.
32MB 70-ns Industry standard
0101
X.X.
32MB 80-ns Industry standard
1110
...X
16MB 60-ns Industry standard
1010
.X.X
16MB 70-ns IBM and Industry standard
0110
X..X
16MB 80-ns Industry standard
1011
.X..
8MB 70-ns IBM and Industry standard
1000
.XXX
8MB 80-ns IBM and Industry standard
1000
.XXX
4MB 70-ns Industry standard
0100
X.XX
4MB 70-ns IBM
0100
X.XX
4MB 80-ns Industry standard
0000
XXXX
4MB 80-ns IBM
1001
.XX.
2MB 70-ns Industry standard
1100
..XX
2MB 70-ns IBM
0101
X.X.
2MB 80-ns Industry standard
1001
.XX.
2MB 80-ns IBM
0101
X.X.
2MB 85-ns IBM
1110
...X
2MB 100-ns IBM
1010
.X.X
1MB 70-ns Industry standard
0110
X..X
1MB 80-ns Industry standard
0110
X..X
1MB 85-ns IBM
0010
XX.X
1MB 100-ns IBM
1111
  Connector is empty


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