41CL How to install CLUTILS-4H

[Ángel Martin]

(06-19-2018 02:33 PM)CY-CL Wrote:  What is stored in witch section? A diagram like for the HP-41 memory pages would be very helpful to understand better the internal memory structure from a CL.

Let me throw a few basic concepts to get you going:-

You can think of flash memory as a gigantic repository where hundreds of ROMS are pre-stored from the factory. It is a non-volatile storage space, so its contents is permanent even without batteries.

There's also a RAM section on the CL board that can hold dozens of ROM modules. This section comes EMPTY and is available for use. CL_RAM contents will be lost if the batteries are removed from the calculator - but won't be affected by MEMORY LOST, since the CL RAM is not the same as the "HP-41 pages".

- You can copy ROMs from flash into CL_RAM. You can also burn flash sectors using the contents of RAM blocks.

The way FLASH and CL_RAM are utilized is as follows:

- The CL has the same number of "pages" available to the O/S as the standard HP-41, i.e. 16 in total: 8 internal and 8 in the plug-in ports.

- The CL uses a facility called "MMU" to map any of those ROMS into CL "pages". Obviously the O/S is mapped to pages 0,1,2,3, the Time module to page 5, and the HP-IL (when connected) to pages 6 and 7.

- Except the O/S mentioned above, this ROM-mapping is totally flexible and configurable by the user. It can even be modified from within a FOCAL program running if you want.

Hope this helps getting over the hump.

ÁM