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:^[1]

        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 (the TOPS-10 system prompt is the . at the start of lines):

.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 (Disk LISTing) option to the COMPILE command:

HELLO WORLD     MACRO %53B(1247) 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(1247) 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.^[2]

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.^[3]

References

1. Wolfram Rösler,"The Hello World Collection". Retrieved on 5 April 2009.
2. "99 Bottles of Beer" Retrieved on 10 April 2009.
3. Trailing Edge PDP-10 software archive

External links

• DECsystem-10 Macro Assembler Reference Manual (PDF). Maynard, Massachusetts: Digital Equipment Corporation. April 1978. Retrieved 2010-07-08.
• Singer, Michael (1978). Introduction to DECsystem-10 Assembler Language Programming. New York: John Wiley & Sons. p. 145. ISBN 0-471-03458-4.
• Gorin, Ralph E (1981). Introduction to DECSYSTEM-20 Assembly Language Programming. Bedford, Massachusetts: Digital Press. p. 539. ISBN 0-932376-12-6.