U UNIVAC 1218 - Bitsavers

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