*
* This is the hand translation for SNES 65c816 assembler
* by Chris Burke.
*
* The translation includes additional comments to help
* with debugging and to clarify the operation of the
* original code. I also like to spread out my code a
* bit by inserting blank lines after control transfers.
*

*
*   Code
*

* Entry point. Name pointer is at 1+2,S
* Returns process ID or match in long A

    LONGA   ON
* Start after PID #1 (system process)
* Enter with A long

ISRUNNIN
    SA
    LDA     #1
    STA     _IR_PID,Y
    LA
    BRA     _IRC_GO

    LONGA    ON
* Start at current PID #1
* Enter with A long
PIDSCAN

* Common code
* Enter with A long
_IRC_GO
    LDA     _FakeU              ;Was PSHS U,Y / LDD #-64; no U
    PHA
    PHY

    LDA     #-64
    JSL     _STKCHECK

* Main loop
* Enter with A long
    LONGA   ON
_IRC_MAIN
    TYX                         ;Use X for indexing (Y less capable)
    INC     _IR_PID,X           ;WAS INC _IR_PID,Y
     BEQ    _IRC_NO             ;BRANCH IF NO MATCH

    PHX                         ;Was LEAX _IR_PBUF,Y ;GET THIS PROC'S DESCRIPTOR
    LDA     #_IR_PBUF
    CLC
    ADC     1+0,S
    PLX                         ;Clean stack temp
    TAX

    SA                          ;Use short A
    LDA     _IR_PID,Y
    LA
    JSL     F_GPRDSC
     BCS    _IRC_MAIN

* Compare names and quit on match
* NOTE: Enter with A long
_IRC_CMP
    LDA     1+6,S               ;Was LDX 6,S ;RECOVER POINTER TO CALLER'S NAME
    TAX
    BSR     _IRC_CMP
     BCC    _IRC_YES

    BRA     _IRC_MAIN

* No match -- clean stack and return 0
* NOTE: Enter with A long
_IRC_ERR1
_IRC_NO
    PLY                         ;Was PULS Y,U,PC
    PLA
    STA     _FakeU

    LDA     #0                  ;Order changed so we get right N,Z flags
    
    RTS

* Found a match -- clean stack and return the matching PID.
* NOTE: Enter with A long
_IRC_YES
    PLY                         ;Was PULS Y,U,PC
    PLA
    STA     _FakeU

    SA
    LDA     _IR_PID,Y           ;Order changed so we get right N,Z flags (same Y)
    LA
    AND     #$00FF

    RTS