; Print AL
space:	mov al, ' '
putc:	xor bx, bx
	mov ah, 0x0e
	int 0x10
	ret

	; Print code string CS:SI
putcs:	push ds
	push cs
	pop ds
	call putds
	pop ds
	ret

	; Print data string DS:SI
putds:	lodsb
	test al, al
	jz .ret
	call putc
	jmp putds
.ret:	ret

crlf:	mov al, 0x0A
	call putc
	mov al, 0x0D
	jmp putc

print16:
	; setup bx and ah for int 10h call
	xor bx, bx
	mov ah, 0x0e
	mov cl, 4
	; this double-call is essentially a 4 times repeating loop
	call .c1
.c1:	call .c2
.c2:	; grab highest nibble from dx
	mov al, dh
	; remove highest nibble from dx
	shl dx, cl
	; shift away second-highest nibble that we accidentally copied
	shr al, cl
	; map 0-9 to ascii codes for '0' to '9'
	add al, 0x30
	; if result is larger than '9', ...
	cmp al, 0x3a
	jl .noadj
	; ... add 7 so we continue at 'A'
	add al, 7
.noadj:	int 0x10
	ret

	; Read character
getc:	xor ax, ax
	int 0x16
	test al, al
	jz getc
	test al, 0x80
	jnz getc
	ret

	; Read uppercased character
getcu:	call getc
	cmp al, 'a'
	jc .ret
	cmp al, 'z'
	ja .ret
	and al, 0xDF
.ret:	ret

	; Read hexadecimal character
getch:	call getcu
	; everything above F is invalid
	cmp al, 'F'
	ja getch
	; everything above or equal A is ok
	cmp al, 'A'
	jae .ret
	; everything above 9 is invalid
	cmp al, '9'
	ja getc
	; everything above or equal 0 is valid
	cmp al, '0'
	jae .ret
	; everything above or equal ' ' is invalid
	cmp al, ' '
	jae getch
.ret:	ret

	; Read string into inbuf
	; IN	ingetc	ptr to getc function
	;	inlen	max number of chars
gets:	mov di, inbuf
	; calculate max pointer for writing
	mov dx, [inmin]
.loop:	call [ingetc]
	; test for Ctrl+C, Enter and Backspace
	cmp al, 0x03
	je .can
	cmp al, 0x0D
	je .enter
	cmp al, 0x08
	je .bs
	; ignore other ctl chars
	cmp al, 0x20
	jc .loop
	; check if we are full
	mov bx, di
	sub bx, inbuf
	; bl is now number of characters we have
	cmp bl, dh
	jnc .loop
	stosb
	call putc
	jmp .loop
	; backspace: print, print space, print backspace again
.bs:	cmp di, inbuf
	jbe .loop
	push ax
	call putc
	call space
	pop ax
	call putc
	dec di
	jmp .loop
	; ctrl+c: return with carry set
.can:	stc
	ret
	; enter: if enough chars, return
.enter:	mov bx, di
	sub bx, inbuf
	cmp bl, dl
	jc .loop
	xor al, al
	stosb
	ret