PAGE
;BIOS8 - Utility routines.




;	Check blocked disk transfer.
;
;	EXIT	Cbit set, unblocked device.
;		Cbit clear, blocked device.

CHKBKD:	proc
	STOB	#0,ERFLAG	;Clear error flag
	LD	AL,SEKTYP
	CMP	AL,#DSKD1
	JL	CBKD2		;If not blocked device
	CMP	AL,#MAXFTP
	JG	CBKD1		;If hard disk
	LD	AX,SEKTRK
	OR	AX,AX
	LD	AL,#DSKS1	;A = Single density
	JZ	CBKD2		;If zero force non-blocked

CBKD1:	sto	ds,bufseg
	LD	AL,SAVSEC
	STO	AL,SEKSEC
	CLC			;Clear carry flag
	RET


SETACT:	LD	AL,SEKTYP
CBKD2:	STO	AL,ACTTYP	;Set actual disk type
	LD	AX,DMAADR
	STO	AX,BUFADR
	LD	BX,DMASEG
	STO	BX,BUFSEG

	LD	AL,SEKDSK
	STO	AL,ACTDSK
	LD	BX,SEKTRK
	STO	BX,ACTTRK
	LD	AL,SAVSEC
	STO	AL,ACTSEC
	STC			;Set carry flag
	RET
	SPACE	4,10
;	Delay	Delay the millisecond count contained in BC.
;
;	Destroys  A and flags.

DELAY:	LD	AL,#DELCNT/21
DLAY1:	DEC	AL
	JNZ	DLAY1		;If not 1 millisecond
	LOOP	DELAY		;If not desired count
:4	RET
	SPACE	4,10
;	Print message terminated by zero byte.
;
;	ENTRY	BX-> message buffer, terminated by zero.
;
;	EXIT	BX-> zero byte + 1.
;		A = 0.
;		Z bit set.
;
;	Destroys only BX, Flags, and A registers.

:6:	PUSH	CX
	MOV	CL,AL
	CALL	J.COUT		;Output to the console
	POP	CX
PRINT:
	LD	AL,[bx]		;Get a character
	INC	BX
	TEST	AL,AL
	JNZ	:6		;if no EOS
	RET


;	Endx	Bios8