PS/2 Memory Reference
PS/2 SIMM-Memory SYSTEM-BOARD Matrix
#-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) Specifications
(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
|
|
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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