diff --git a/armagedec.tcl b/armagedec.tcl
index 880f2b6..408e53c 100755
--- a/armagedec.tcl
+++ b/armagedec.tcl
@@ -7,7 +7,7 @@
 
 package require Tk
 
-set appversion 0.4
+set appversion 0.5
 set scriptpath [file normalize [info script]]
 set appdir [file dirname $scriptpath]
 # check if we're running from a starpack
@@ -293,21 +293,22 @@ proc wa_roundtime_write {num} {
 
 # fixedpoint helpers
 proc fixed2float {fpint} {
-  set whole [expr {int($fpint) >> 16}]
-  set frac [expr {int($fpint) & 65535}]
-  return [expr {$whole + ($frac / 65536)}]
+  set fpint [expr {int($fpint)}]
+  set whole [expr {$fpint >> 16}]
+  set frac [expr {$fpint % 65536}]
+  return [expr {$whole + ($frac / 65536.)}]
 }
 
 proc float2fixed {flt} {
-  set whole [expr {int(double($flt))}]
-  set frac [expr {double($flt) - $whole}]
-  return [expr {($whole << 16) | int($frac * 65536)}]
+  set whole [expr {int($flt)}]
+  set frac [expr {$flt - $whole}]
+  return [expr {($whole << 16) | int($frac * 65536.)}]
 }
 
 # v3-only spec functions
 
 proc wa_petrolturndecay_read {raw} {return [fixed2float $raw]}
-proc wa_petrolturndecay_write {num} {return [expr int($num * 65536)]}
+proc wa_petrolturndecay_write {num} {return [expr int($num * 65536.)]}
 
 # general logic
 
@@ -341,7 +342,7 @@ proc fullscanscheme {version} {
     set delay 0
     set prob 0
     catch {
-      binary scan [string range $rawschemedata $offs [expr {$offs + 4}]] cucucucu ammo power delay prob
+      binary scan [string range $rawschemedata $offs [expr {$offs + 3}]] cucucucu ammo power delay prob
     }
     set wsc_data($offs) $ammo
     set wsc_data($poweroffs) $power
@@ -360,7 +361,7 @@ proc fullscanscheme {version} {
     if {$size eq 2} {set fmt s}
     if {$size eq 4} {set fmt i}
     set newval ""
-    binary scan [string range $rawschemedata $offs [expr {$offs + $size}]] $fmt newval
+    binary scan [string range $rawschemedata $offs [expr {$offs + $size - 1}]] $fmt newval
     if {$newval ne ""} {set wscval $newval}
     if {([llength $valopt] > 1) && ([lindex $valopt 0] eq "spec")} {
       set readfunc "[lindex $valopt 1]_read"
@@ -474,7 +475,7 @@ proc savescheme {fname} {
       if {$size eq 2} {set fmt s}
       if {$size eq 4} {set fmt i}
       if {([llength $valopt] > 1) && ([lindex $valopt 0] eq "spec")} {
-        set writefunc "[lindex $valopt 1]_read"
+        set writefunc "[lindex $valopt 1]_write"
         set val [$writefunc $val]
       } elseif {$valopt eq "fixp"} {
         set val [float2fixed $val]