IBM PS/2 90 XP 486 Hardware Maintenance Reference page 23

2.4.1 Memory Requirements and Limitations
Whenever memory is added or removed from the system, run Automatic
configuration from the Main Menu of the system programs.
Note: If memory fails, and the customer runs diagnostics, the defective
memory is disabled.
indicate the amount of memory that is enabled.
After the defective memory is replaced, run the advanced diagnostic memory
test to enable the replacement memory.
Memory operation varies depending on which processor board is installed.
Systems can be upgraded with a different processor board than the type
indicated on the system serial number label.
installed, you must start the system programs, go to the Main Menu and
select Display revision levels (on some models, you must select More
utilities first). Make note of the submodel code displayed on the screen.
The following table converts the submodel code to the type of error
detection, memory configuration, and processor board installed.
+------------------------------------------------------------------------+
¦ Model 90 ¦ Model 95
¦ Sub- model ¦ Sub- model
¦ Code ¦ Code
¦ ¦
¦ ¦
+-------------+--------------+--------------+--------------+-------------¦
¦ ¦
¦ 2F ¦ 2E
¦ 11 ¦ 14
¦ 13 ¦ 16
¦ 2B ¦ 2A
¦ 2D ¦ 2C
¦ 57 ¦ 58
¦ 59 ¦ 5A
¦ 5B ¦ 5C
¦ 3F ¦ 40
¦ 29 ¦ 28
¦ ¦
+------------------------------------------------------------------------+
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Memory Requirements and Limitations
When you run diagnostics, the system will
To verify which board is
¦ Memory ¦ Error
¦ (Interleaved)¦ Detection
¦ (Non- ¦ (Parity)
¦ interleaved) ¦ (ECC) or
¦ or (Both) ¦ (Both)
¦ ¦
¦ Interleaved ¦ Parity
¦ Interleaved ¦ Parity
¦ Interleaved ¦ Parity
¦ Interleaved ¦ Parity
¦ Interleaved ¦ Parity
¦ Both ¦ Parity
¦ Both ¦ Parity
¦ Both ¦ Parity
¦ Both ¦ Parity
¦ Interleaved ¦ Both
¦ ¦
¦ Copyright IBM Corp. 1990, 1992
2.4.1 - 1
¦ Processor ¦
¦ Board Type ¦
¦ Installed ¦
¦ ¦
¦ ¦
¦ ¦
¦ Type 1 ¦
¦ Type 1 ¦
¦ Type 1 ¦
¦ Type 1 ¦
¦ Type 1 ¦
¦ Type 2 ¦
¦ Type 2 ¦
¦ Type 2 ¦
¦ Type 2 ¦
¦ Type 3 ¦
¦ ¦