SOME TRAP ERRORS HAVE BEEN CAUSED BY INCORRECT MEMORY BEING USED. THE TABLE BELOW GIVES THE MANUFACTURING P/N'S, RESISTORS PRESENT AT THE TOP RIGHT (IBM MANUFACTURED) OR MANUFACTURER CODE MARKING ON THE SIMM CASING MADE BY VENDOR FOR THE DIFFERENT SPEEDS AND SYSTEMS WHERE USED.
P/N23F9779 IS THE IBM MANUFACTURED 100NS MEMORY AND IS RECOGNIZED BY THE R1 AND R2 RESISTORS AT THE TOP RIGHT. P/N68X6254 IS THE VENDOR MANUFACTURED EQUIVALENT AND HAS ONE OF THE MARKINGS. EITHER ONE CAN BE USED IN THE 8570 16MHZ OR 8555.
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PART NUMBER | SPEED | MARKINGS | WHERE USED
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23F9779(IBM)| 100 | R1 AND R2 RESISTORS | 8570 16MHZ
____________| |__________________________|
68X6254(OEM)| | MSC2321-10YS18A | AND
| | HB56D512361B-10 |
| | MH512361B-10 | 8555
| | ZA3617 |
| | THM265102S-10 |
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65X6249(IBM)| 85 | ONLY R1 RESISTER | 8570 20MHZ
____________| |__________________________| 8555
68X6127(OEM)| | MNB36512S85 | 8570 16MHZ
| | THM365120S-85 | OPTION
| | MSC2321-85YS18A | 6450605/9
| | HB56D512361B-8 |
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68X5806(IBM)| 80 | ONLY R2 RESISTOR | 8570-A21
| | | 8570-R21
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