* DISASSEMBLY BY DYNAMITE OF 1.BOOT.BIN
* STANDARD PRE-NAMED LABEL EQUATES
CMDADR EQU $C100
* EXTERNAL LABEL EQUATES
LE000 EQU $E000 FLOPPY CTLR
LE001 EQU $E001
LE002 EQU $E002
LE003 EQU $E003
STACK EQU $C0FF
SCTBUF EQU $C300
 ORG $C100
START BRA START1
 FCB $00,$00
 FCB $00
FLXTRK FCB $01 FILE START TRACK
 FCB $01 FILE START SECTOR
 FCB $00
TADR FCB $C1,$00
LADR1 FCB $00
 FCB $00
SIDEID FCB $00
START1 LDS #STACK SETUP STACK
 LDD FLXTRK GET TRANSFER ADDRESS
 STD SCTBUF SETUP STARTING TRK & SCT
 LDY #SCTBUF+256
*
* PERFORM ACTUAL BOOT LOAD
*
LOAD1 BSR GETCH GET A CHARACTER
 CMPA #2 DATA RECORD HEADER ?
 BEQ LOAD2 SKIP IF SO
 CMPA #$16 XFR ADDRESS HEADER?
 BNE LOAD1 LOOP IF NEITHER
 BSR GETCH GET TRANSFER ADDRESS
 STA TADR
 BSR GETCH
 STA TADR+1
 BRA LOAD1 CONTINUE LOAD
LOAD2 BSR GETCH GET LOAD ADDRESS
 STA LADR1
 BSR GETCH
 STA LADR1+1
 BSR GETCH GET BYTE COUNT
 TFR A,B PUT IN B
 TSTA
 BEQ LOAD1 LOOP IF COUNT = 0
 LDX LADR1 GET LOAD ADDRESS
LOAD3 PSHS B,X
 BSR GETCH GET A DATA CHARACTER
 PULS B,X
 STA 0,X+ PUT CHARACTER
 DECB END OF DATA IN RECORD?
 BNE LOAD3 LOOP IF NOT
 BRA LOAD1 GET ANOTHER RECORD
*
* GET CHARACTER ROUTINE
*
GETCH CMPY #SCTBUF+256 OUT OF DATA?
 BNE GETCH4 GO READ CHARACTER IF NOT
 LDX #SCTBUF POINT TO BUFFER
 LDD 0,X GET FORWARD LINK
 BEQ GO IF ZERO, FILE IS LOADED
 BSR READ READ NEXT SECTOR
 BNE START START OVER IF ERROR
 LDY #SCTBUF+4 POINT PAST LINK
GETCH4 LDA 0,Y+ ELSE GET A CHARACTER
 RTS
*
* FILE IS LOADED, JUMP TO IT
*
GO JMP [TADR]
*
* READ SINGLE SECTOR
*
READ BSR SELTRK
 TST SIDEID TEST SIDE
 BNE READ0
 LDA #$8C READ A SECTOR SIDE 0
 BRA READ1 SIDE 0, JUMP
READ0 LDA #$8E READ A SECTOR SIDE 1
READ1 STA LE000 COM REGISTER
 BSR DELAY
 CLRB
 LDX #SCTBUF
READN LDA LE000 LOADS STATUS
 BITA #2 TEST DATA READY ?
 BNE READ3 YES, JUMP
 BITA #1 STILL BUSY ?
 BNE READN NO, NEXT
 TFR A,B
 BRA L009D
READ3 LDA LE003 GET DATA
 STA 0,X+ STORE IN SECTOR BUFFER
 DECB SECTOR FINISHED ?
 BNE READN NO, NEXT
 BSR TEST
L009D BITB #$1C CRC, SEEK OR LOST DATA ERROR ?
 RTS
TEST LDB LE000
 BITB #1 BUSY ?
 BNE TEST LOOP TO WAIT
 RTS
SELTRK CLR SIDEID
 CMPB #$0A IS IT SIDE 2
 BLS SELTR1 NO, SIDE 1
 DEC SIDEID YES, CHANGE SIDE
SELTR1 STB LE002 SECREG
 CMPA LE001 TRKREG
 BEQ DELAY OK, TRACK IS OK
 STA LE003 DATREG SET TRACK
 BSR DELAY
 LDA #$1B SEEK NEW TRACK CMD
L00C1 STA LE000 CMDREG
 BSR DELAY
 BSR TEST
DELAY JSR DEL1
 JSR DEL1
DEL1 RTS
 ORG $C1F5
 FCB $50,$56
 END START