diff --git a/kernel/char.asm b/kernel/char.asm
deleted file mode 100644
index 4c1998e..0000000
--- a/kernel/char.asm
+++ /dev/null
@@ -1,140 +0,0 @@
-section .data
-
-conbx	dw 7
-
-section .text
-
-	; raw console output
-	; IN	dl	character
-conout	mov al, dl
-	mov ah, 0x0e
-	mov bx, [cs:conbx]
-	int 0x10
-	ret
-
-	; check if character has characters ready
-	; OUT	al	0xFF if data, 0 if none
-const	mov ah, 1
-	int 0x16
-	jz .emp
-	mov ax, 0xFF
-	ret
-.emp	mov al, 0
-	ret
-
-	; read character from console
-	; OUT	al	character or zero
-conin	call const
-	test al, al
-	jz .ret
-	mov al, 0
-	int 0x16
-.ret	ret
-
-	; dummy: write to auxillary dev
-auxout	ret
-
-	; dummy: read from auxillary dev
-auxin	mov al, 0x1A
-	ret
-
-	; dummy: lister out
-lstout	ret
-
-	; character input with echo
-	; OUT	al	character
-getc	call const
-	test al, al
-	jz getc
-	call conin
-	push ax
-	mov dl, al
-	call putc
-	pop ax
-	ret
-
-	; character input without echo
-readc	call const
-	test al, al
-	jz readc
-	jmp conin
-
-	; character output
-	; IN	dl	character
-putc	jmp conout
-
-	; direct console I/O
-	; IN	dl	character to output or 0xFF if input
-	; OUT	al	character to read
-dcon	cmp dl, 0xFF
-	je conin
-	jmp conout
-
-	; output character string
-	; IN	ds:dx	far ptr to string, '$'-terminated
-puts	push si
-	mov si, dx
-.loop	lodsb
-	cmp al, '$'
-	je .ret
-	mov dl, al
-	call putc
-	jmp .loop
-.ret	pop si
-	ret
-
-	; send a beep ctl to console
-beep	mov dl, 0x07
-	jmp conout
-
-	; buffered input
-	; IN	ds:dx	far ptr to buffer
-gets	mov si, dx
-	mov cx, [si]
-	mov ch, 0
-	; ch = actual number of chars
-	; cl = maximum number of chars
-.loop	call readc
-	cmp al, 0x0D
-	je .cr
-	cmp al, 0x08
-	je .bs
-	cmp al, 0x20
-	jc .loop
-	; check if there is space in the buffer
-	; emit a beep if not
-	mov dl, cl
-	dec dl
-	cmp ch, dl
-	jc .append
-	call beep
-	jmp .loop
-	; append to buffer
-.append	mov bh, 0
-	mov bl, ch
-	mov [si+2+bx], al
-	inc ch
-	mov dl, al
-	call putc
-	jmp .loop
-	; handle backspace
-.bs:	test ch, ch
-	jz .loop
-	mov dl, 0x08
-	call putc
-	mov dl, 0x20
-	call putc
-	mov dl, 0x08
-	call putc
-	dec ch
-	jmp .loop
-	; handle carriage return
-.cr	mov bx, 0
-	mov bl, ch
-	mov [si+2+bx], al
-	mov [si], cx
-	mov dl, 0x0A
-	call putc
-	mov dl, 0x0D
-	call putc
-	ret
diff --git a/src/@rdos.asm b/src/@rdos.asm
index 4d3c5de..2dfac29 100644
--- a/src/@rdos.asm
+++ b/src/@rdos.asm
@@ -12,6 +12,141 @@ DRVEXT	equ 0x04 ; bit 2 - EBIOS supported
 DIRTY	equ 0x08 ; bit 3 - dskbuf dirty
 DRVCHS	equ 0x10 ; bit 4 - CHS geometry known
 
+	; raw console output
+	; IN	dl	character
+conout	xchg ax, dx
+	mov ah, 0x0e
+	mov bx, 7
+	int 0x10
+	ret
+
+	; check if character has characters ready
+	; OUT	al	0xFF if data, 0 if none
+const	mov ah, 1
+	int 0x16
+	jz .emp
+	mov ax, 0xFF
+	ret
+.emp	mov al, 0
+	ret
+
+	; read character from console
+	; OUT	al	character or zero
+conin	call const
+	test al, al
+	jz .ret
+	mov al, 0
+	int 0x16
+.ret	ret
+
+	; dummy: write to auxillary dev
+auxout	ret
+
+	; dummy: read from auxillary dev
+auxin	mov al, 0x1A
+	ret
+
+	; dummy: lister out
+lstout	ret
+
+	; character input with echo
+	; OUT	al	character
+getc	call const
+	test al, al
+	jz getc
+	call conin
+	push ax
+	mov dl, al
+	call putc
+	pop ax
+	ret
+
+	; character input without echo
+readc	call const
+	test al, al
+	jz readc
+	jmp conin
+
+	; character output
+	; IN	dl	character
+putc	jmp conout
+
+	; direct console I/O
+	; IN	dl	character to output or 0xFF if input
+	; OUT	al	character to read
+dcon	cmp dl, 0xFF
+	je conin
+	jmp conout
+
+	; output character string
+	; IN	ds:dx	far ptr to string, '$'-terminated
+puts	push si
+	mov si, dx
+.loop	lodsb
+	cmp al, '$'
+	je .ret
+	mov dl, al
+	call putc
+	jmp .loop
+.ret	pop si
+	ret
+
+	; send a beep ctl to console
+beep	mov dl, 0x07
+	jmp conout
+
+	; buffered input
+	; IN	ds:dx	far ptr to buffer
+gets	mov si, dx
+	mov cx, [si]
+	mov ch, 0
+	; ch = actual number of chars
+	; cl = maximum number of chars
+.loop	call readc
+	cmp al, 0x0D
+	je .cr
+	cmp al, 0x08
+	je .bs
+	cmp al, 0x20
+	jc .loop
+	; check if there is space in the buffer
+	; emit a beep if not
+	mov dl, cl
+	dec dl
+	cmp ch, dl
+	jc .append
+	call beep
+	jmp .loop
+	; append to buffer
+.append	mov bh, 0
+	mov bl, ch
+	mov [si+2+bx], al
+	inc ch
+	mov dl, al
+	call putc
+	jmp .loop
+	; handle backspace
+.bs:	test ch, ch
+	jz .loop
+	mov dl, 0x08
+	call putc
+	mov dl, 0x20
+	call putc
+	mov dl, 0x08
+	call putc
+	dec ch
+	jmp .loop
+	; handle carriage return
+.cr	mov bx, 0
+	mov bl, ch
+	mov [si+2+bx], al
+	mov [si], cx
+	mov dl, 0x0A
+	call putc
+	mov dl, 0x0D
+	call putc
+	ret
+
 	align 16
 	; IBM Interrupt Sharing Protocol structure
 i13isp	jmp short int13i
@@ -268,18 +403,18 @@ diskio	mov cl, 1 ; read len
 	; dx = cylinder, ax = head * spt + sector
 	div byte [drvspt]
 	; dx = cylinder, al = head, ah = sector
-	xchg dl, dh
-	ror dl, 1
-	ror dl, 1
-	or dl, ah
-	inc dx
-	; al: head number
-	; dh bit 0-7: cylinder bits 0-7
-	; dl bit 0-5: sector bits 0-5
-	; dl bit 6-7: cylinder bits 8-9
+	xchg ax, dx
+	xchg al, ah
+	ror al, 1
+	ror al, 1
+	or al, dh
+	inc ax
+	; dl: head number
+	; ah bit 0-7: cylinder bits 0-7
+	; al bit 0-5: sector bits 0-5
+	; al bit 6-7: cylinder bits 8-9
 	; shuffle values around for bios
 	xchg ax, cx
-	xchg cx, dx
 	xchg dh, dl
 	mov bx, dskbuf
 .do	mov dl, [biosnum]