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To use this mode properly the programmer must do what is done when using any other symbolic
address except that the symbol must start with a
$
sign, and must be in a modulo 16 address
in the first 8192 words of memory.
The two remammg techniques for specifying the desired address are pure symbolic and decimal.
Examples of these are:
LDA
CONST3
LDA
WSl
LDA
5
LDA
511
LDA
8000
CONST 3 and WSl are symbolic addresses; and 5, 511, and 8000 are decimal addresses. The
General Assembly Program checks the desired address, if it is in the same program bank as
the instruction being assembled.
If
it is, address modification mode 0 or 1 (program bank
addressing) is assigned along with the correct partial address.
If
it is not in the same program
bank, it is checked for being in the common data bank.
If
it is, address modification mode 2
(common data bank addressing) is assigned along with the correct partial address.
If
neither
case applies, it is not possible to generate the address directly. The assembly program flags
this condition with an A on the assembly program output listing. This indicates an invalid
address and must be corrected.
With program banks of 1,024 words, most desired addresses will be either in the common
data bank or in the same program bank. The first assembly by the General Assembly Program
will indicate the addresses which need to be changed to indirect addressing.
@&u&~[EuCJ ~@------------
A-19
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