		Notes on MIXAL, the MIX assembly language

It should be pretty obvious if you've coded in assembler before and if you've
read the instruction-set description.  A few things that may not be obvious:

Spaces aren't allowed in the operand field.  (That's why you can put
comments after the operand field, without any special comment character.)

Forward references are not allowed in expressions.

An expression is evaluated strictly left-to-right, with no operator
precedence.

In line 12 of prime.mix:

	ld1	=1-L=

the =1-L= denotes a memory location automatically placed by the assembler
after your code, containing the value 1-L.  Syntactically, =1-L= is like a
forward reference.  (Note that 

	ent1	1-L

is equivalent but more efficient.)

The character  *  in the operand field denotes the current address of 
assembly.  Thus,

	jmp	*

is a one-instruction infinite loop.

The funny two-letter labels starting with a digit are local labels:
In an instruction like

	jmp	2F

the 2F refers to the next occurrence of 2H as a label; in

	jmp	2B

the 2B refers to the last occurrence of 2H as a label.

There's more, but that should be enough to get by with until you procure
a copy of Knuth.  I'm awfully sick of typing.  Sorry.
