U UNIVAC 1218 - Bitsavers
U UNIVAC 1218 - Bitsavers
U UNIVAC 1218 - Bitsavers
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CHANGE 1<br />
3 0 5 GROUND RULES<br />
Regardless of the input format, there are certain conventions which the programmer<br />
must bear in mind when coding for TRIM III.<br />
1) No label may exceed six characters. The label must not begin with a<br />
number, the letter 0, nor may it consist only of letters LOK. The label<br />
may never contain a +, -, comma, or point separator code.<br />
2) The maximum size program which TRIM III can assemble is limited only by<br />
the number of memory locations above address 130008 used for label/tag<br />
storage (3 words per label or tag).<br />
3) Each break in addressing sequence constitutes a program area. A total<br />
of 64 such areas is permitted.<br />
4) TRIM I operators SETADR and EQUALS are ignored by TRIM III. The ALLOC<br />
operation replaces these two functions.<br />
5) When specifying a decimal integer, the letter D occupies one digit position:<br />
therefore, the maximum decimal integer that can be expressed is 99999D.<br />
6) Assembler support subroutines TYPT, TYPC, PCHT, PCHC, and the debugging<br />
package, DEBUG, are included in the TRIM III library of subroutines. The<br />
programmer uses a CALL operation to retrieve them from the library. The<br />
programmer may allocate these subroutines through normal ALLOC operations.<br />
If he does not allocate them, TRIM III will assign them sequential<br />
addresses immediately following the principal program. If these subroutines<br />
are not assembled with the principal program and the programmer<br />
has not provided for their allocation, TRIM III will arbitrarily assign<br />
all references to them to the following fixed addresses:<br />
TYPT 17000<br />
TYPC 17160<br />
PCHT 16400<br />
PCHC 16560<br />
DEBUG 17470<br />
Each of these five subroutines uses the tag CHAN for all I/O instructions.<br />
It is the programmer's responsibility to provide an ALLOC operation<br />
equating CHAN to the appropriate I/O channel.<br />
7) If a program contains ADDA, ADDAB, SUBA, or SUBAB instructions, regardless<br />
of whether or not a DBLSET operation was used, the following restrictions<br />
shall apply to loading a TRIM III output NOg 5, 10, or 13 into computer<br />
memory:<br />
a) If the program was assembled starting at an even address, it must be<br />
loaded starting at an even address.<br />
III-C-34