Base And Current Page - HP 9835A Programming Manual

The Processor and the Operating System
29
o
CPU registers
37
(reserved)
40 . (at least 1 word) starting address
min =41 .......... """""" ............
-~""""""
............ - ......... .......:....--..................
---<
dependent upon
user data
(ICOM area)
system needs
ending address
, dependent upon
max = 77756 .................
---~(~re-s-e-rv-e""l'd):-------li--<'
starting address,
77777
~
length of ICOM,
(at least 1710 words)
I
100000 and system needs
177617
177620
177701
177702
177703
177704
177705
177767
177770
177773
177774
177777
-r
(reserved)
, - -
-
Base_page
Oper_1
Op_er 2
Result
(reserved)
Ar1
(reserved)
Figure 6. Memory Map
Base and Current Page
lower block
upper block
A concept that occasionally arises during discussion of the instructions and the assembler is that
of the "page", the "base" and "current" pages in particular.
A page is 1 024 words of memory.