;
; A sample function in CSM format. This is "getchar", out of the std
; library:
;
	maclib <bds>

	function	getchar

	lda ungetl	;any character pushed back?
	ora a
	mov l,a
	jz gch2
	xra a		;yes. return it and clear the pushback
	sta ungetl	;byte in C.CCC.
	mvi h,0
	ret

gch2:	push b
	mvi c,conin
	call bdos
	pop b
	cpi cntrlc	;control-C ?
	jz base		;if so, reboot.
	cpi 1ah		;control-Z ?
	lxi h,-1	;if so, return -1.
	rz
	mov l,a
	cpi cr		;carriage return?
	jnz gch3
	push b
	mvi c,conout	;if so, also echo linefeed
	mvi e,lf
	call bdos
	pop b
	mvi l,newlin	;and return newline (linefeed)..

gch3:	mvi h,0
	ret

	endfunc getchar