Mister-E,

Took your advice, here is the test program i tried;

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'e:\plc\pbp245\PBPW.exe -p18f452 e:\2005\FZ4\452LED.bas

ALED var portb.0
high ALED
pause 1000
low ALED
end
------

and now the associated compilationerror messages.
-------------------

Error E:\PLC\PBP245\452LED.ASM 44 : [225] Undefined Symbol 'TRISB'
Error E:\PLC\PBP245\452LED.ASM 45 : [225] Undefined Symbol 'TRISC'
Error PBPPIC18.LIB 156 : [225] Undefined Symbol 'PORTB'
Error PBPPIC18.LIB 187 : [225] Undefined Symbol 'PORTC'
Error PBPPIC18.LIB 362 : [225] Undefined Symbol 'PORTA'
Error PBPPIC18.LIB 368 : [225] Undefined Symbol 'PORTA'
Error PBPPIC18.LIB 380 : [225] Undefined Symbol 'PORTB'
Error PBPPIC18.LIB 1153 : [200] Instruction Restricted to 14-Bit Core
Error PBPPIC18.LIB 1153 : [218] Address Limit of FFFFh Exceeded
Error PBPPIC18.LIB 6215 : [200] Instruction Restricted to 14-Bit Core
Error PBPPIC18.LIB 6215 : [218] Address Limit of FFFFh Exceeded
Error PBPPIC18.LIB 6216 : [200] Instruction Restricted to 14-Bit Core
Fatal PBPPIC18.LIB 6216 : [300] Too Many Errors
PicBasic Pro Compiler 2.45, (c) 1998, 2004 microEngineering Labs, Inc.
All Rights Reserved.
--------------------------

You dont think there may be errors in the .ASM or .LIB files listed above??
I was of the assumption that both the 16F877and the 18F452 were both 14bit devices.

any help from any one would be greatly appreciated.

cheers
Woodzy