diff --git a/codeGenVirtual/src/prog8/codegen/virtual/ExpressionGen.kt b/codeGenVirtual/src/prog8/codegen/virtual/ExpressionGen.kt
index 9017df8eb..96c1b3eb7 100644
--- a/codeGenVirtual/src/prog8/codegen/virtual/ExpressionGen.kt
+++ b/codeGenVirtual/src/prog8/codegen/virtual/ExpressionGen.kt
@@ -226,15 +226,13 @@ internal class ExpressionGen(val codeGen: CodeGen) {
                 code += VmCodeInstruction(Instruction(Opcode.XOR, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg))
             }
             "<<" -> {
-                // TODO check if shift amount works
                 code += VmCodeInstruction(Instruction(Opcode.LSL, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg))
             }
             ">>" -> {
-                // TODO check if shift amount works
                 code += VmCodeInstruction(Instruction(Opcode.LSR, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg))
             }
             "**" -> throw AssemblyError("** operator requires floating point ${binExpr.position}")
-            // TODO the other operators: "<<", ">>", "==", "!=", "<", ">", "<=", ">="
+            // TODO the other operators: "==", "!=", "<", ">", "<=", ">="
             else -> TODO("operator ${binExpr.operator}")
         }
         return code
diff --git a/compiler/res/prog8lib/virtual/syslib.p8 b/compiler/res/prog8lib/virtual/syslib.p8
index a10c814cb..cba444dd2 100644
--- a/compiler/res/prog8lib/virtual/syslib.p8
+++ b/compiler/res/prog8lib/virtual/syslib.p8
@@ -8,10 +8,35 @@ sys {
 
     const ubyte target = 255         ;  compilation target specifier.  64 = C64, 128 = C128,  16 = CommanderX16, 8 = atari800XL, 255 = virtual
 
+    ; SYSCALLS
+    ; 0 = reset ; resets system
+    ; 1 = exit ; stops program and returns statuscode from r0.w
+    ; 2 = print_c ; print single character
+    ; 3 = print_s ; print 0-terminated string from memory
+    ; 4 = print_u8 ; print unsigned int byte
+    ; 5 = print_u16 ; print unsigned int word
+    ; 6 = input ; reads a line of text entered by the user, r0.w = memory buffer, r1.b = maxlength (0-255, 0=unlimited).  Zero-terminates the string. Returns length in r65535.w
+    ; 7 = sleep ; sleep amount of milliseconds
+    ; 8 = gfx_enable  ; enable graphics window  r0.b = 0 -> lores 320x240,  r0.b = 1 -> hires 640x480
+    ; 9 = gfx_clear   ; clear graphics window with shade in r0.b
+    ; 10 = gfx_plot   ; plot pixel in graphics window, r0.w/r1.w contain X and Y coordinates, r2.b contains brightness
+
+    const ubyte SC_RESET = 0
+    const ubyte SC_EXIT = 1
+    const ubyte SC_PRINT_C = 2
+    const ubyte SC_PRINT_S = 3
+    const ubyte SC_PRINT_U8 = 4
+    const ubyte SC_PRINT_u16 = 5
+    const ubyte SC_INPUT = 6
+    const ubyte SC_SLEEP = 7
+    const ubyte SC_GFX_ENABLE = 8
+    const ubyte SC_GFX_CLEAR = 9
+    const ubyte SC_GFX_PLOT = 10
+
 
     sub  reset_system()  {
         ; Soft-reset the system back to initial power-on Basic prompt.
-        ; TODO
+        syscall(SC_RESET)
     }
 
     sub wait(uword jiffies) {
@@ -38,7 +63,7 @@ sys {
 
     sub exit(ubyte returnvalue) {
         ; -- immediately exit the program with a return code in the A register
-        ;    TODO
+        syscall1(SC_EXIT, returnvalue)
     }
 }
 
diff --git a/compiler/res/prog8lib/virtual/textio.p8 b/compiler/res/prog8lib/virtual/textio.p8
index 642ccc9a5..86dcc8b0a 100644
--- a/compiler/res/prog8lib/virtual/textio.p8
+++ b/compiler/res/prog8lib/virtual/textio.p8
@@ -87,14 +87,14 @@ sub  print_uwhex  (uword value, ubyte prefix) {
 sub  print_uw0  (uword value)  {
     ; ---- print the uword value in decimal form, with left padding 0s (5 positions total)
     ; TODO use conv module?
-    ubyte tenthousands = value / 10000 as ubyte
-    value -= tenthousands * 10000
-    ubyte thousands = value / 1000 as ubyte
-    value -= thousands * 1000
-    ubyte hundreds = value / 100 as ubyte
-    value -= hundreds*100
-    ubyte tens = value / 10 as ubyte
-    value -= tens*10
+    ubyte tenthousands = (value / 10000) as ubyte
+    value -= 10000*tenthousands
+    ubyte thousands = (value / 1000) as ubyte
+    value -= 1000*thousands
+    ubyte hundreds = (value / 100) as ubyte
+    value -= 100 as uword * hundreds
+    ubyte tens = (value / 10) as ubyte
+    value -= 10*tens
     chrout(tenthousands+'0')
     chrout(thousands+'0')
     chrout(hundreds+'0')
@@ -104,14 +104,14 @@ sub  print_uw0  (uword value)  {
 
 sub  print_uw  (uword value)  {
     ; ---- print the uword in decimal form, without left padding 0s
-    ubyte tenthousands = value / 10000 as ubyte
-    value -= tenthousands * 10000
-    ubyte thousands = value / 1000 as ubyte
-    value -= thousands * 1000
-    ubyte hundreds = value / 100 as ubyte
-    value -= hundreds*100
-    ubyte tens = value / 10 as ubyte
-    value -= tens*10
+    ubyte tenthousands = (value / 10000) as ubyte
+    value -= 10000*tenthousands
+    ubyte thousands = (value / 1000) as ubyte
+    value -= 1000*thousands
+    ubyte hundreds = (value / 100) as ubyte
+    value -= 100 as uword * hundreds
+    ubyte tens = (value / 10) as ubyte
+    value -= 10*tens
     if tenthousands
         goto print_tenthousands
     if thousands
diff --git a/examples/test.p8 b/examples/test.p8
index 3230a8ea8..c7a0b6a18 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -6,6 +6,18 @@ main {
     sub start() {
         txt.clear_screen()
         txt.print("Welcome to a prog8 pixel shader :-)\n")
+        ubyte bb = 10
+        uword ww = 123
+        bb <<= 4
+        ww <<= 5
+        txt.print("bb=")
+        txt.print_ub(bb)
+        txt.nl()
+        txt.print("ww=")
+        txt.print_uw(ww)
+        txt.nl()
+        sys.exit(99)
+
 
         syscall1(8, 0)      ; enable lo res creen
         ubyte shifter