41CL: Can someone to explain this index?

[cgh]

(07-03-2018 09:58 AM)Podalirius Wrote:  Hi, I studied many 41CL manuals and don't understand this:
in the instruction to insert the Library#4 in page 4 on write in Alpha register
"804040-8120" where 804040 is the address of page 4 and 120 is the address of LIB#4.
But the '8' in 8120 what is? It is possible to have other value in place of this?
I searched in sy41cl, mem_ref, cl_memory and cl_extreme manuals.
Thank you for your greatly appreciated help!

This bit means that this page is enabled. This is described in NEWT Microprocessor Technical Manual (newt.pdf) pages 11 and 12 when explaining the memory organization and the MMU mechanism.