HP41CL serial export of ROM

[dingebre]

(02-13-2017 07:35 PM)Monte Dalrymple Wrote:  

(02-13-2017 07:07 PM)dingebre Wrote:  I "YPEEK"ed into the MMU register that contains the pointer to the Page B HEPAX [...]

The MMU register arrangement is shown in the figure on page 67 of the manual. The most-significant nibble contains control information (enabled/locked/type), while the lower three nibbles contain the physical page address to substituted for the logical page address. In the example you asked about, RAM page 808 (starting address 0x808000) is what is plugged into page B. The upper nibble indicates that MMU translation is enabled, the page is not locked, and it is a single page image.

For your second question, the figure on page 30 shows how to specify a logical address to copy into RAM. The image needs to be in RAM before it can be exported.

Hope this helps.
Monte

Thanks Monte. This helped a lot. I think I was able to successfully transfer the HPEAX page to the laptop. I just need to re-read about the memory structure a few more times to understand it better before I start to mess with it too much.

David