41CL: Can someone to explain this index?

[Podalirius]

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!

[Ángel Martin]

(07-03-2018 09:58 AM)Podalirius Wrote:  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.

My understanding is that the "8" digit in that string is required for compatibility reasons with other functions that use a similar format in ALPHA. So it needs to be there, and no other value is allowed.

An easier way to plug the Library#4 is to use the YFNX - the YFunctions Extreme. The PLUG function in that module will allow you to specify page #4 as destination.

[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.

[Monte Dalrymple]

(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!

Note 2 on page 31 of mem_ref.pdf explains how each bit in an MMU entry is used.