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@ -94,7 +94,7 @@ Different projects have led to the architecture of PLASMA, most notably Apple Pa
- [Call Stack](#call-stack)
- [Local Frame Stack](#local-frame-stack)
- [Local String Pool](#local-string-pool)
- [The Bytecodes](#the-bytecodes)
- [The Bytecodes](https://github.com/dschmenk/PLASMA/wiki/PLASMA-Byte-Codes)
- [Apple 1 PLASMA](#apple-1-plasma)
- [Apple II PLASMA](#apple-ii-plasma)
- [Apple /// PLASMA](#apple--plasma)
@ -1313,80 +1313,6 @@ One of the biggest problems to overcome with the 6502 is its very small hardware
Any function that uses in-line strings may have those strings copied to the local string pool for usage. This allows string literals to exist in the same memory as the bytecode and only copied to main memory when used. The string pool is deallocated along with the local frame stack when the function exits.
### The Opcodes
The compact code representation comes through the use of opcodes closely matched to the PLASMA compiler. They are:
| OPCODE | Name | Description
|:------:|:------:|-----------------------------------
| $00 | ZERO | push zero on the stack
| $02 | ADD | add top two values, leave result on top
| $04 | SUB | subtract next from top from top, leave result on top
| $06 | MUL | multiply two topmost stack values, leave result on top
| $08 | DIV | divide next from top by top, leave result on top
| $0A | MOD | divide next from top by top, leave remainder on top
| $0C | INCR | increment top of stack
| $0E | DECR | decrement top of stack
| $10 | NEG | negate top of stack
| $12 | COMP | compliment top of stack
| $14 | AND | bit wise AND top two values, leave result on top
| $16 | IOR | bit wise inclusive OR top two values, leave result on top
| $18 | XOR | bit wise exclusive OR top two values, leave result on top
| $1A | SHL | shift left next from top by top, leave result on top
| $1C | SHR | shift right next from top by top, leave result on top
| $02 | IDXB | add top of stack to next from top, leave result on top (ADD)
| $1E | IDXW | add 2X top of stack to next from top, leave result on top
| $20 | NOT | logical NOT of top of stack
| $22 | LOR | logical OR top two values, leave result on top
| $24 | LAND | logical AND top two values, leave result on top
| $26 | LA | load address
| $28 | LLA | load local address from frame offset
| $2A | CB | constant byte
| $2C | CW | constant word
| $2E | CS | constant string
| $30 | DROP | drop top stack value
| $32 | DUP | duplicate top stack value
| $34 | NOP |
| $36 | DIVMOD | divide next from to by top, leave result and remainder on stack
| $38 | BRGT | branch next from top greater than top
| $3A | BRLT | branch next from top less than top
| $3C | BREQ | branch next from top equal to top
| $3E | BRNE | branch next from top not equal to top
| $40 | ISEQ | if next from top is equal to top, set top true
| $42 | ISNE | if next from top is not equal to top, set top true
| $44 | ISGT | if next from top is greater than top, set top true
| $46 | ISLT | if next from top is less than top, set top true
| $48 | ISGE | if next from top is greater than or equal to top, set top true
| $4A | ISLE | if next from top is less than or equal to top, set top true
| $4C | BRFLS | branch if top of stack is zero
| $4E | BRTRU | branch if top of stack is non-zero
| $50 | BRNCH | branch to address
| $52 | IBRNCH | branch to address on stack top
| $54 | CALL | sub routine call with stack parameters
| $56 | ICAL | sub routine call to address on stack top with stack parameters
| $58 | ENTER | allocate frame size and copy stack parameters to local frame
| $5A | LEAVE | deallocate frame and return from sub routine call
| $5C | RET | return from sub routine call
| $5E | CFFB | constant with $FF MSB
| $60 | LB | load byte from top of stack address
| $62 | LW | load word from top of stack address
| $64 | LLB | load byte from frame offset
| $66 | LLW | load word from frame offset
| $68 | LAB | load byte from absolute address
| $6A | LAW | load word from absolute address
| $6C | DLB | duplicate top of stack into local byte at frame offset
| $6E | DLW | duplicate top of stack into local word at frame offset
| $70 | SB | store next from top of stack byte into top address
| $72 | SW | store next from top of stack word into top address
| $74 | SLB | store top of stack into local byte at frame offset
| $76 | SLW | store top of stack into local word at frame offset
| $78 | SAB | store top of stack into byte at absolute address
| $7A | SAW | store top of stack into word at absolute address
| $7C | DAB | duplicate top of stack into byte at absolute address
| $7E | DAW | duplicate top of stack into word at absolute address
The opcodes were developed over time by starting with a very basic set of operations and slowly adding opcodes when the PLASMA compiler could improve code density or performance.
## Apple 1 PLASMA
Obviously the Apple 1 is a little more constrained than most machines PLASMA is targeting. But, with the required addition of the CFFA1 (http://dreher.net/?s=projects/CFforApple1&c=projects/CFforApple1/main.php), the Apple 1 gets 32K of RAM and a mass storage device. Enough to run PLASMA and load/execute modules.