E.A.L. - Code Reference
EAL produces a small set of pCode for runtime execution.
The first digit is the generic op-code followed by its mnemonic.
'sg' is a segment-count used only with variable-operations, followed by 'ac', the op-code's argument.
(All op-codes act on a 'lifo'-stack.)
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# OPC sg ac comment
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0 XOP 0 0 return XOP ... executive op-code
1 switch sign
2 minus
3 plus
4 mult
5 div
6 eq
7 ne
8 lt
9 le
10 gt
11 ge
12 odd
13 NOP
14 ask
15 tell
1 PSH 0 ac push - pushs a value to TOS (Top Of Stack)
2 LOD sg ac load - pushs a variable from sg-base + ac (base-offset) to TOS
3 STO sg ac store - pulls a value from TOS to a variable (sg-base + ac)
4 CAL sg ac call - creates a new segment-base (activation record) on a function call
5 ALC 0 ac allocate - allocates stack-space by incrementing the top-pointer by ac
6 JMP 0 ac jump - sets the program-counter to ac
7 JPC 0 ac jump on condition - jumps to ac if TOS eq 0
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The trace- and log-functions list the following values:
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P: xx TOS: xx > MMM sg ac func
P: xx ... program-counter/step
TOS: xx ... top-of-stack value
MMM ... mnemonic
sg ... segment-count
ac ... argument
func ... function (XOP only)
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(Thanks to N. Wirth for enlightenment.)
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N.Landsteiner 02.1999