diff --git a/kernel/intr.asm b/kernel/intr.asm
index 7542223..2d7eca8 100644
--- a/kernel/intr.asm
+++ b/kernel/intr.asm
@@ -1,123 +1,23 @@
-; Data table for interrupts
-; cs:word for service routine
-intr_table0:
-  dw iret ; 00 Divide by Zero
-  dw iret ; 01 Single Step
-  dw iret ; 02 Parity error routine (NMI)
-  dw debug_reg_ir ; 03 Break
-  dw iret ; 04 Overflow
-  dw iret ; 05 Print Screen
-  dw iret ; 06 Mouse button control
-  dw isr_dosmain ; 07 Reserved
-  dw irq0 ; 08 System Clock interrupt
-  dw irq1 ; 09 Keyboard interrupt
-  dw irq2 ; 0a RTC interrupt
-  dw irq3 ; 0b COMMS
-  dw irq4 ; 0c COMMS
-  dw irq5 ; 0d Hard Disk
-  dw irq6 ; 0e Floppy Disk interrupt routine
-  dw irq7 ; 0f Printer interrupt
-intr_table2:
-  dw iret ; 20
-  dw isr_dosmain ; 21
-  dw iret ; 22
-  dw iret ; 23
-  dw iret ; 24
-  dw iret ; 25
-  dw iret ; 26
-  dw iret ; 27
-  dw iret ; 28
-  dw iret ; 29
-  dw iret ; 2a
-  dw iret ; 2b
-  dw iret ; 2c
-  dw iret ; 2d
-  dw iret ; 2e
-  dw iret ; 2f
-
-; LSB is IRQ0, MSB is IRQ16
-; A IRQ will set their bit to 1, so userspace may poll it via wait_irq
-intr_flip:
-  dw 0
-
-intr_init:
-  push ds
-  push es
-  ; backup intr 0x0n to 0x4n
+; Register a interrupt handler
+; in:	sp:bp+0  interrupt number
+;	     +2  handler offset
+; out:  sp:bp+4
+intr_register:
+  ; use data stack
+  xchg sp, bp
+  ; ES := 0
   xor ax, ax
-  mov ds, ax ; read from IVT
-  mov es, ax ; write to IVT
-  mov si, ax ; read from start of IVT table
-  mov di, 0x0100 ; write to offset of int 0x40 address
-  mov cx, 0x0020 ; 0x10 vectors, segment:offset each
-  repe movsw
-  ; now setup our own handlers (0x0n)
+  mov es, ax
+  ; DI := intnum * 4
+  pop di
+  sal di, 1
+  sal di, 1
+  ; copy offset from arguments
+  pop ax
+  stosw
+  ; copy our segment
   mov ax, cs
-  mov ds, ax ; read from local segment
-  mov si, intr_table0 ; read from intr_table
-  mov di, 0x0000 ; write to start of IVT table
-  mov cx, 0x0010 ; 0x10 vectors, one offset each
-.loop0:
-  movsw ; read offset; write offset
-  mov ax,cs
-  stosw ; write segment
-  loop .loop0
-  ; second vector block (0x2n)
-  mov si, intr_table2 ; read from intr_table
-  mov di, 0x0080 ; write to int 20h vector and above
-  mov cx, 0x0010 ; 0x10 vectors, one offset each
-.loop2:
-  movsw ; read offset; write offset
-  mov ax,cs
-  stosw ; write segment
-  loop .loop2
-  pop es
-  pop ds
-  ret
-
-irq0:
-  int 0x48
-  or byte [cs:intr_flip], 0x01
-  jmp irqret
-
-irq1:
-  int 0x49
-  or byte [cs:intr_flip], 0x02
-  jmp irqret
-
-irq2:
-  int 0x4A
-  or byte [cs:intr_flip], 0x04
-  jmp irqret
-
-irq3:
-  int 0x4B
-  or byte [cs:intr_flip], 0x08
-  jmp irqret
-
-irq4:
-  int 0x4C
-  or byte [cs:intr_flip], 0x10
-  jmp irqret
-
-irq5:
-  int 0x4D
-  or byte [cs:intr_flip], 0x20
-  jmp irqret
-
-irq6:
-  int 0x4E
-  or byte [cs:intr_flip], 0x40
-  jmp irqret
-
-irq7:
-  int 0x4F
-  or byte [cs:intr_flip], 0x80
-  jmp irqret
-
-hwiret:
-  mov al,20h
-  out 20h,al
-irqret:
-iret:
-  iret
\ No newline at end of file
+  stosw
+  ; use code stack
+  xchg sp, bp
+  ret
\ No newline at end of file
diff --git a/kernel/kprintf.asm b/kernel/kprintf.asm
deleted file mode 100644
index d1f1b0b..0000000
--- a/kernel/kprintf.asm
+++ /dev/null
@@ -1,140 +0,0 @@
-; important functions in this file: kprintf
-
-; write a character to kernel output
-; in: al
-kputc:
-  push ax
-  push bx
-  mov bx, 0x0000
-  mov ah, 0x0e
-  int 0x10
-  pop bx
-  pop ax
-  ret
-
-; write a string to kernel output
-; in: ds:di
-kputs:
-  push ax
-.loop:
-  lodsb
-  cmp al,0x00
-  je .end
-  call kputc
-  jmp .loop
-.end:
-  pop ax
-  ret
-
-; prints a nibble in hex
-; in: al
-kprint4:
-  and al, 0x0F
-  add al, 0x30
-  cmp al, 0x3a
-  jl kputc
-  add al, 0x07
-  jmp kputc
-
-; print a byte
-; in: al
-kprint8:
-  push ax ; avoid destroying ah
-  aam 16 ; high nibble moved into ah
-  xchg ah,al ; high nibble first
-  call kprint4
-  xchg ah,al
-  call kprint4
-  pop ax
-  ret
-
-; print a word
-; in: ax
-kprint16:
-  xchg ah,al
-  call kprint8
-  xchg ah,al
-  call kprint8
-  ret
-
-; read a word from the stack, using bp as stack pointer
-; in: bp
-; out: ax, bp
-kprintf_lodsw:
-  push ds ; work segment for lodsw
-  push si ; work pointer for lodsw
-  push ss ; data transfer to ds
-  pop ds
-  mov si,bp
-  lodsw
-  mov bp,si ; write back incremented value
-  pop si
-  pop ds
-  ret
-
-; print data from stack
-; in: ds:si, ss:sp
-kprintf:
-  push ax
-  push bp ; state variable for stack lodsw
-  push si ; return original pointer to caller
-  mov ax, sp
-  add ax, 0x08
-  mov bp, ax
-.loop:
-  lodsb
-  cmp al,0x00
-  je .end
-  cmp al,0x25 ; '%'
-  je .fseq
-  call kputc
-  jmp .loop
-.end:
-  pop si
-  pop bp
-  mov al,0x0A
-  call kputc
-  mov al,0x0D
-  call kputc
-  pop ax
-  ret
-.fseq:
-  lodsb
-  cmp al,0x00
-  je .end
-  cmp al,0x25 ; '%'
-  je .fmt_pc
-  cmp al,0x63 ; 'c'
-  je .fmt_c
-  cmp al,0x73 ; 's'
-  je .fmt_s
-  cmp al,0x78 ; 'x'
-  je .fmt_x
-  cmp al,0x58 ; 'X'
-  je .fmt_X
-  mov al,0x3F ; '?'
-  call kputc
-  jmp .loop
-.fmt_pc:
-  mov al,0x25
-  call kputc
-  jmp .loop
-.fmt_c:
-  call kprintf_lodsw
-  call kputc
-  jmp .loop
-.fmt_s:
-  push si
-  call kprintf_lodsw
-  mov si,ax
-  call kputs
-  pop si
-  jmp .loop
-.fmt_x:
-  call kprintf_lodsw
-  call kprint8
-  jmp .loop
-.fmt_X:
-  call kprintf_lodsw
-  call kprint16
-  jmp .loop
diff --git a/kernel/main.asm b/kernel/main.asm
index bb92176..a44cdda 100644
--- a/kernel/main.asm
+++ b/kernel/main.asm
@@ -5,13 +5,6 @@ optrom_length:
   db 0x00
   jmp optrom_init
 
-str_vendor:
-  db "Nero", 0
-
-align 16
-str_product:
-  db "Nero DOS", 0
-
 times (0x1A - ($-$$)) db 0
   dw pnp
 
@@ -36,13 +29,13 @@ pnp:
 
 align 16
 optrom_init:
-  xor ax, ax
-  mov es, ax
-  mov di, 0x0060 ; vector (0x18 * 4 bytes)
-  mov ax, start
-  stosw
-  mov ax, cs
-  stosw
+  ; setup data stack below code stack
+  mov bp, sp
+  sub bp, 0x80
+  ; intnum and offset to data stack
+  mov word [ss:bp], 0x18
+  mov word [ss:bp+2], start
+  call intr_register
   retf
 
 putc:
@@ -57,6 +50,8 @@ putc:
 
 announce:
   push cs
+  mov ax, cs
+  mov ds, ax
   mov ax, str_product
   push ax
   call printf
@@ -65,42 +60,26 @@ announce:
   ret
 
 start:
-  mov ax, cs
+  xor ax, ax
   mov ds, ax
+  mov es, ax
+  ; setup code + data stack
+  mov ss, ax
+  mov sp, ax
+  mov bp, sp
+  ; data stack starts 512 bytes below code stack
+  sub bp, 0x200
 
   call announce
 
-  ; clear memory until 0x01000
-  xor ax, ax
-  mov es, ax
-  mov di, 0x500
-  mov cx, 0xB00
-  rep stosb
+  sub bp, 4
+  mov word [ss:bp], 3
+  mov word [ss:bp+2], isr_debug
+  call intr_register
 
-  call intr_init
   sti
 
-  sub sp, 0x10
-  mov si, sp
-  mov word [ss:si+0x00], 0
-  mov word [ss:si+0x02], 1
-  mov word [ss:si+0x04], 0
-  mov word [ss:si+0x06], 0x2000
-  mov word [ss:si+0x08], 0x07fc
-  mov word [ss:si+0x0A], 0
-  mov word [ss:si+0x0C], 0
-  mov word [ss:si+0x0E], 0
-  mov ah, 0x42
-
-  push ss
-  pop ds
-  call ramdisk_io
-  push ax
-  call printf
-  db "AX=%X", 0x0A, 0x0D, 0x00
-  pop ax
-
-  add sp, 0x10
+  int 3
 
 .halt:
   hlt
@@ -111,9 +90,5 @@ start:
 
 %include "intr.asm"
 %include "debug.asm"
-%include "kprintf.asm"
-%include "dosapi.asm"
-
-_reloc_end:
 
 align 512
\ No newline at end of file