HOW TO REMOVE THE SERIAL NUMBER FROM "PROFESSIONAL BASIC" Professional Basic, by Morgan Computing, has a serial number embedded in the code which the program checks in order to begin running a Basic program. It will not execute a Basic program if the serial number is "corrupted". Here is how to "corrupt" the serial number and retain the full functions of PB.EXE. You will need a "disk zap" program such as SecMod, Disk Explorer, or Media Magician. The serial number is contained in the PB.EXE file in the 216th sector of the program, at hex offset DE. It is preceeded by the words "Serial Number is" and is followed by a zero byte. Use your disk zapper to change the serial number to whatever you wish, and record the EXACT sequence of bytes you put there. DO NOT "clobber" more than nine (9) bytes of serial number. Now go to the next-to-last sector of PB.EXE. This is sector number 289, relative to the start of the program. At hex offset 25 in this sector is a nine-byte string which is an encoded version of the original serial number. This is the "copy" which PB uses to detect "corruption" of the plain text serial number. To enter a "copy" corresponding to your new serial number, perform the following operations: Using a piece of paper, write the "new" serial number down, but ROTATE IT 5 characters to the RIGHT. For example, if your new serial number is "YO HO HO ", the rotated string becomes: "O HO YO H" Now add one to the byte value of each of the rotated characters. You might have to refer to a table of ascii codes to do this. In the example above, you'll get: "P!IP!ZP!I" This is the text string to use to replace the "copy" string in sector 289, offset 25H. Let There Be Software!  This is the text string to use to replace the "copy" string in sector 289,