;------------------------------------------------------------------------------
;
;				      1541
;
;	This source code generates the ROM for the 1541 in the address
;	range $E000-$FFFF. The code for this version is:
;
;				    901229-01
;
;------------------------------------------------------------------------------


.ba $E5B6
;**  Cbm dos v2.6 1541
.by $73					; 73
.tz 'CBM DOS V2.6 1541'


.ba $E979
	lda	VIC20mode		; VIC-20 ?
	bne	A_E980			; yes, no slowdown needed, ->

	jsr	DelayC64		; delay for serial bus for C64
A_E980:					;				[E980]
	jsr	P_FEFB			; set DATA OUT and CLOCK OUT


.ba $FC86
	inx				; X := 1  WHY? is said to be bug


.ba $FEE6
.by $FD					; checksum


.ba $FEF3
;**  Delay loop for serial bus in 1541 mode from $E97D
DelayC64:				;				[FEF3]
	txa
	ldx	#$05			; about 40 microseconds
Delay2:					;				[FEF6]
	dex
	bne	Delay2

	tax
	rts


;**  Patch for data output to serial bus from $E980
P_FEFB:					;				[FEFB]
	jsr	ClkOut_H		; CLOCK OUT hi
	jmp	DataOut_L		; DATA OUT lo


;**  U9 vector, switch 1540/1541
UI_U9:
	lda	CMDBUF+2
	cmp	#'-'
	beq	A_FF0D

; if parameter is '+', then at A_FF0D result is 0
	sec
	sbc	#'+'
	bne	NMI			; indirect jump over ($0065)
A_FF0D:					;				[FF0D]
	sta	VIC20mode

	rts


.ba $FFFA
.wo	UI_U9				;** UI, U9


.ba $FFFC
;**  Hardware vectors


;******************************************************************************