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IBM 5162  -  RAM Information


0 KB to 640 KB

Commonly known as conventional memory.
In IBM 5162 documentation and software, IBM refers to this as 'base' memory.
In the 5162, conventional memory addressed 0 KB to 512 KB, resides on the motherboard in SIMM's S1 and S2.
- A location diagram is here.
- A diagram showing bit breakdown is here.
- Both SIMMs need to be present.
- According to here, in the 5162, "industry-standard 30-pin, of 256KB, with parity, of 150ns access time (or faster), of 256cycle/4ms refresh", should work as a substitute to what was fitted by IBM.
- If either SIMM fails, the symptoms presented depend on the type of video card fitted:
      * MDA or CGA card: You will see a 201 error which points to address 000000.
      * Other: No visual nor audible indication. A POST card will reveal the situation (per here).
In the 5162, conventional memory addressed 512 KB to 640 KB, resides on the motherboard in the six RAM chips adjacent to the power connector.
- A location diagram is here.
- A diagram showing bit breakdown is here.
- If required, this memory can be disabled via jumper block J10.


640 KB to 1 MB

Refer to the diagram here.


1 MB to 16 MB

Commonly known as extended memory.
In IBM 5162 documentation and software, IBM refers to this as 'expansion' memory.  Do not confuse 'expansion' with 'expanded'.
In an IBM 5162, conventional memory does NOT have to be at the 640 KB maximum before extended memory is added.
Rules: Extended memory must start at the 1 MB address, and be contiguous (no gaps).
For example, if you have three 2 MB extended memory cards, the cards would be configured as follows:
         CARD #1: Address 1 MB to 3 MB
         CARD #2: Address 3 MB to 5 MB
         CARD #3: Address 5 MB to 7 MB
If you break any of the two rules, the 5162 will not 'find' all of your RAM.


RAM Count during POST

During the 5162's POST (power-on self test), a RAM count is displayed on-screen.
The count shown is the RAM amount, not the RAM address.

Note that any expanded memory is not detected, nor checked, by the POST.