Programming instructions

APPENDIX 6
Programming Aids
The following programming aids are supplied with the PDP-4.
PDP-4 ASSEMBLY PROGRAM -A one-pass assembler which allows
mnemonic symbols to be used for addresses and instructions. Constants
are automatically assigned. Text statements may be written for printing
at run time, and a decimal mode may be specified. Up to six character
symbols may be used, and the symbol table may be punched on paper
tape for use with the debugging tape below.
DDT-4 DEBUGGING TAPE - Provides communication with a program
via the on-line typewriter. Registers may be examined (using mnemonic
codes) and modified. Communication is entirely in symbolic language.
Programs may have break points inserted and then run under DDT-4
control, similar to a tracing routine. A program may be searched for par-
ticular words.
DOUBLE-PRECISION FLOATING POINT PACKAGE- Provides floating-
point arithmetic with a 36-bit mantissa and 18-bit exponent. The routines
include plus, minus, divide, multiply, fix-to-float, and float-to-fix, with
decimal input and output.
MAINTENANCE ROUTINES-There are five maintenance routines. These
tests are also used as DEC’s standard acceptance test routines.
(a) CONTEST (CONtinuous TEST) - Verifies that all machine functions
are performing properly. Each instruction is tested, a core checker-
board pattern is run, a tape is punched and read, and a message
is typed. The test then repeats itself.
(b) INSTEP (INStruction TEst Programs)-Test all machine instruc-
tions under various modes.
(c) Checkerboard Program - Provides continuous memory testing
with four different patterns.
(d) Reader and Punch Test-Checks the start time of the reader aind
checks the reader using different patterns and variable times. The
punch is tested by providing tapes for the reader test.
(e) Teleprinter Test.
TAPE REPRODUCER - Reproduces tape using the Interrupt Mode.
PUNCH ROUTINES -Allow punching in either block format or read-in
mode format.
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