MACRO-10


MACRO-10 is an assembly language with extensive macro facilities for DEC's PDP-10-based Mainframe computer systems, the DECsystem-10 and the DECSYSTEM-20. MACRO-10 is implemented as a two-pass assembler.

Programming examples

A simple "Hello, world!" program in MACRO-10 assembler, to run under TOPS-10, adapted from a specimen in a large collection of "Hello World" programs in various languages:

TITLE HELLO WORLD
; 'Hello world' in MACRO-10 for TOPS-10
SEARCH UUOSYM ; Make UUO symbol names available
LAB: ASCIZ /Hello, world!
/ ; NUL-terminated ASCII string with CRLF
START: RESET ; Initialise job to clean runtime state
OUTPUT: OUTSTR LAB ; Output string starting at LAB:
MONRT. ; Return to monitor
JRST OUTPUT ; Restart at OUTPUT: if user CONTINUEs job
END START ; End assembly, set program start address

If this program is saved in the file HELLO.MAC, it can be assembled, linked and run like this :

.COMPILE HELLO.MAC /DLIST
MACRO: HELLO
EXIT
.LOAD HELLO
LINK: Loading
EXIT
.SAVE
HELLO saved
.RUN
Hello, world!

The assembly listing file generated by the /DLIST option to the COMPILE command:

HELLO WORLD MACRO %53B 17:29 7-Apr-:9 Page 1
HELLO MAC 7-Apr-:9 17:29
TITLE HELLO WORLD
; 'Hello world' in MACRO-10 for TOPS-10
SEARCH UUOSYM ; Make UUO symbol names available
000000' 110 145 154 154 157 LAB: ASCIZ /Hello, world!
000001' 054 040 167 157 162
000002' 154 144 041 015 012 / ; NUL-terminated ASCII string with CRLF
000003' 000 000 000 000 000
000004' 047 00 0 00 000000 START: RESET ; Initialise job to clean runtime state
000005' 051 03 0 00 000000' OUTPUT: OUTSTR LAB ; Output string starting at LAB:
000006' 047 01 0 00 000012 MONRT. ; Return to monitor
000007' 254 00 0 00 000005' JRST OUTPUT ; Restart at OUTPUT: if user CONTINUEs job
000004' END START ; End assembly, set program start address
NO ERRORS DETECTED
PROGRAM BREAK IS 000010
CPU TIME USED 58:25.100
36P CORE USED
HELLO WORLD MACRO %53B 17:29 7-Apr-:9 Page S-1
HELLO MAC 7-Apr-:9 17:29 SYMBOL TABLE
LAB 000000'
MONRT. 047040 000012
OUTPUT 000005'
OUTSTR 051140 000000
RESET 047000 000000
START 000004'

The date ":9" is a Year 2000 problem.
A more complex MACRO-10 example program, which renders one version of the 99 Bottles of Beer song, may be examined at the "99 Bottles of Beer" web site.
For larger bodies of code, much of the MACRO-10 code for the TOPS-10 and TOPS-20 systems is available in the Trailing Edge PDP-10 tape archives.