assembler and emulator
is an assembler and emulator for Donald Knuth’s
architecture. The command assembles the named
files into memory and then presents a command
prompt to control an emulated
option causes the emulator immediately to run a complete assembled
program and exits when the emulator halts.
The following commands are accepted:
Print the value at
An optional field specification is given by
a [< file]
Start the MIXAL assembler. The assembler will begin
assembling at the address after the last assembled
instruction. If no file is given, the assembler will
accept instructions from the console.
Set or unset a breakpoint at
machine to a fresh state by clearing all memory
Disassemble the instruction at
Print the alphanumeric
alphanumeric mix words starting at
Print the value in register
where * is one of a, x, ax, j, or 1-6. An optional
field specification is given by
Step through one instruction of the emulated
Start the emulated
machine at the instruction specified by the
Quit the emulator/assembler.
field of the above instructions must be an integer between 0 and 3999
inclusive. A number-sign (#) or an asterisk (*) at the beginning of
a line starts a comment which extends to the end
of the line.
Donald Knuth, “The Art of Computer Programming”, Volume 1. Section 1.3
As opposed to Knuth’s specification,
pseudo-instruction takes as argument five
characters surrounded by quotation marks.
Unresolved forward references are assembled
to 0 instead of to a location determined by
The magnetic tapes and drum units are not
Comments are handled as described above and not
exactly as Knuth specifies.