Atari 400 Technical Reference Manual page 342

ERR LINE ADDR B1 B2 B3 B4
MONITOR *****
MONITP.SRC
*****
3/9/79
*****
4:00 PAGE 81
3561 RESET BUTTON ROUTINE STARTS HERE
3562 i*****************************************************************
3563
3564 F1lB 78
RESET:
SEI
iDISABLE IRG INTERRUPTS
3565 F1IC AD 44 02 LDA COLDST
iWERE WE IN MIDDLE OF COLDSTART?
3566 F1IF DO 04 BNE PWRUP
i
YES, GO TRY IT AGAIN
3567 F121 A9 FF LDA
#$FF
3568 F123 DO 03 BNE
PWRUPl iSET WARM START FLAG
3569
3570
3571
3572 i***************************************************************
3573
POWER UP ROUTINES START HERE
3574 i***************************************************************
3575
3576 F125
78
PWRUP: SEI
iDISABLE IRG INTERRUPTS
3577 F126 A9 00 LDA
#0 iCLEAR WARMSTART FLAG
3578 F128 85 08 PWRUPl : STA
WARMST
3579 F12A D8 CLD
iCLEAR DECIMAL FLAG.
3580 F12B A2 FF LDX
#$FF
3581 F12D 9A TXS
i8ET STACK POINTER
3582 F12E 20 3F F2 JSR SPECL
iCARTRIDGE SPECIAL CASE?
3583 F131 20 77 F2
JSR HARDI iDO HARDWARE INITIALIZATION
3584 F134 A5 08 LDA
WARMST
i
IS IT WARMSTART?
3585 F136
DO 28
BNE ZOSRAM i YES, ONLY ZERO OS RAM
3586
3587 F138 A9 00 ZERORM: LDA
#0
3588 F13A AO 08 LDY
#WARMST
3589 F13C 85 04 STA RAMLO
3590 F13E 85 05 STA RAMLO+1
iINITIALIZE RAM POINTER
3591 F140 91 04 CLRRAM: STA
(RAMLO),Y iCLEAR MEMORY LOC.
3592 F142 C8 INY
3593 F143 CO 00 CPY
#0 i AT END OF PAGE?
3594 F145 DO F9 BNE CLRRAM
3595 F147 E6 05 INC RAMLO+1
i
YES, INCR PAGE POINTER
3596 F149 A6 05 LDX RAMLO+1
3597 F14B E4 06 CPX TRAMSZ
iAT
END OF MEM?
3598 F14D DO F1 BNE CLRRAM
iNO.
3599
3600
INITIALIZE DOSVEC TO POINT TO SIGNON (BLACKBOARD)
3601 F14F AD 72 E4 LDA
BLKBDV+1
3602 F152 85 OA STA
DOSVEC iUSE BLACKBOARD VECTOR
3603 F154 AD 73 E4 LDA
BLKBDV+2 ; FOR DOSVEC
3604 F157 85 OB STA
DOSVEC+1
3605 F159 A9 FF LDA
#$FF
3606 F15B 80 44 02 STA
COLDST iSET TO SHOW IN MIDDLE OF COLDSTART
3607 F15E DO 13 BNE ESTSCM iGO
AROUND ZOSRAM
3608
3609
i
CLEAR OS RAM (FOR WARMSTART)
3610 F160 A2 00 ZOSRAM: LDX #0
3611 F162 SA
TXA
3612 F163 90 00 02
ZOSRM2: STA $200, X iCLEAR PAGES 2 AND 3
3613
F166 90 00 03 STA
$300, X
3614 F169 CA DEX