This library contains macros that have been written to make writing code for the IBM 1401 easier.
The language used is Autocoder.
The Autocoder we are using is written by Van Snyder of JPL.
Van’s Autocoder is 99.9% the same as the Autocoder supplied by IBM back in the 1960’s.

Autocoder never had the #include of modern C++ but a macro call with no arguments in Autocoder works the same.

The HEAD macro supplies all of the base items to write almost any Autocoder program.
The EXIT macro provides the exit routine to end your program.
If SENSE SWITCH G is on, it will branch to START after the halt.
If your code was loaded from a PC, it will return to the loader routing in high memory.
If not, it will read cards from the card reader until it finds the first card of the next program and turn over control to that deck.

A simple ‘hello world’ program looks like this:
               HEAD                 *INVOKE THE HEAD MACRO
     TEXT      DCW  @HELLO WORLD@   *DEFINE THE TEXT
     START     MCW  TEXT,PRINT+12   *MOVE TEXT TO PRINT BUFFER
               W                    *PRINT A LINE
               EXIT                 *EXIT STAGE LEFT
               END  START           *END OF SOURCE CODE AND ID’S THE ENTRY POINT

HEAD.mac
EXIT.mac

Loop macro makes it simple to loop a piece of code.
Hear is how it works with the ‘hello world’ program.
               HEAD                 *INVOKE THE HEAD MACRO
     TEXT      DCW  @HELLO WORLD@   *DEFINE THE TEXT
     COUNT     DCW  @00@            *LOOP COUNTER
     START     MCW  TEXT,PRINT+12   *MOVE TEXT TO PRINT BUFFER
               W                    *PRINT A LINE
               LOOP START,COUNT,@10@
               EXIT                 *EXIT STAGE LEFT
               END  START           *END OF SOURCE CODE AND ID’S THE ENTRY POINT
notes:
1. The size of the second and third variable MUST be of the same length.
2. The second variable shuld not be a literal
3. The third variable may be a variable or a literal
4. The second variable WILL be incremented to the value of the third variable.
   If LOOP is used more than one time in a program, the second parameter 
   MUST be reset before each loop.

LOOP.mac

The following three macros allow you to call and return from procedures
within your Autocoder program.
You must put STACK in your data section before the actual program.
This is a 10 level stack used by KALL and RETRN.
'CALL' is a reserved word in Autocoder so I used KALL.
To call a program, use KALL with the only parameter is tha address of the routine to be 'called'.
Anywhere in that routine, you can use RETRN to the next instruction after the original KALL.
You can use as many RETRN statement as required in your routine.
KALL and RETRN may be used up to 10 levels deep.may be used up to 10 levels deep.
Sample Code:
               HEAD
               STACK
     START     NOP
               KALL FRED     *CALL THE ROUTINE NAMED FRED
               EXIT
     ***************************************
     FRED      MCW  @FRED HERE@,230
               W
               RETRN
               END  START
KALL.mac
RETRN.mac
STACK.mac


MULTP allows you to multiply on the 1401 two number, each from 1 to 10 digits long.
The actual 1401 multiply is not easy to use.
This one is MULTP    name of first value, name of second number, name of where to put the answer.
Sample Code:
               HEAD
     M1        DCW  @123@    *FIRST NUMBER
     M2        DCW  @4567@   *SECOND NUMBER
     ANS       DCW  @00000000@  *ANSWER
     START     NOP
               MULTPM1,M2,ANS   *MULTIPLY
               MCW  M1,PRINT+10
               MCW  M2,PRINT+20
               MCW  ANS,PRINT+25
               W
               EXIT
               END  START

MULTP.mac
DEVID.MAC