A really stupid 41C question

[Didier Lachieze]

(07-01-2022 05:34 AM)Monte Dalrymple Wrote:  The restriction is talking about regular Memory Modules, not X-Mem. The only thing I can think of is that they wanted to make sure that there were no "holes" between Memory Modules?

Yes, according the HP 82106A memory module quick reference:

Quote:To be used properly, memory modules must be inserted
into the ports as specified. Memory modules must be
inserted into the ports in the port’s numeric order, from
port 1 to port 4. Do not insert modules out of order. For
example, if you insert a memory module into port 1 and
then one into port 3, there will be a gap of 64 registers
in memory.

Obviously the HP 82170A quad memory module doesn't have the same constraint, but it was released after the first Application Pacs (and before X-Mem modules):

Quote:The HP 82170A Memory Module can be inserted in
any port and provides the equivalent of four HP
82106A (64-register) memory modules. Only one HP
82170A Memory Module should be inserted in the
calculator at any time. Attempting to use any
additional memory modules in combination with the
HP 82170A Memory Module will not provide an
additional increase in memory and is not recommended
by Hewlett-Packard.