Apple IIc with MultiRAM and ROM4x - RAM-Test, but how ?

Hi everyone,

I recently became the owner of an Apple IIc...

Even before I got the computer, I already had a "Checkmate MultiRAM C" memory expansion lying around. I also had the matching RAM chips on hand to fully populate the card.

Since I want to use an SP2SD with the machine, I swapped the original "255" ROM for a "ROM4x" and modified solder jumpers W1 and W2 accordingly.

I wanted to check if the RAM expansion was actually working, so I first asked the AI ​​Grok how to go about it...

The answer and test procedure: First, enter the Monitor using `call-151` and run the following test:

C073:00 ; IIc internal Aux bank (Bank 0)C003C005C00900:1100 ; should show 11 => OK

C073:01C003C005C00900:2200 ; should show 22 => OK

C073:00C003C005C00900 ; should show 11 again (not 22!) => shows 22.

I don't put too much stock in what the AI ​​says, though, so I thought I'd ask here: is this test supposed to work this way, or is there something else I should try?