MAL I/O

MAL provides a separate I/O instruction for each type of data: character (byte), integer (word) and string (.asciiz). No floating point I/O instructions are included.

The MAL I/O instructions are:

Notes:

1. R is either a general register or a label. The operation is performed on the contents of R.
2. S is either a general register or a label. If S is a general register, the effective address is the contents of S; if S is a label, the effective address is S.
3. Superscripts indicate repetitions of a binary value.
4. Subscripts indicate bit positions (Little-Endian) of sub-field.

The following MAL program reads a string of characters and prints it out in reverse order using an array of bytes. Note that the array index and newline character are stored in registers. RAM is used only for the prompt string and the byte array.