Glossary

Breakpoint - an instruction put in by a disassembler which will return control to it when it is executed. Also something to do with tennis.

Crack/cracking - writing a routine or executing some code which will get round some element of a protection system, enabling the user to put a POKE into the game.

Crash - an undesired effect which the programmer or user did not intend to happen. Classic example is the computer resetting itself to give the old "(C) 1982 Sinclair etc.etc.", or a whole load of flashing squares. Also a now defunct computer magazine.

Decrypter - a short program contained in a protection system which, when run will change garbage into runnable code. You need to crack a decrypter to write a hack for it.

Endless loop - the Multiface equivalent of a breakpoint, put in hacking a protection system or doing a stack trace. The computer will keep executing the same code over and over again, indefinitely, unless the Multiface button is pressed. See also endless loop (ho ho ho!)

Garbage - A block of machine code which does not make sense to a human. The computer will attempt to process it, but will almost certainly crash. Also what the dustmen collect in America.

Hack - a self-standing program which when run will load a game and activate certain cheats. Also the act of getting round a protection system. (See also crack). Also a lot of anonymous people from Scotland.

Headerless loader - a loader which does not contain the first "header part" of a file specifying it's name, length etc, but has it ready built into memory. This makes the program harder to hack.

Interrupt - small program which occurs every 150 of a second, regardless of what the computer is doing.

Loader - any program which reads a file off tape into memory, and executes it. This may consist of simple BASIC commands, a headerless loader, a turboloader or even a protection system.

Operating system - this the built in program into the computer to deal with all the basic things like reading the keyboard and loading software. This is BASIC in the case of the Spectrum. Most protection systems deliberately confuse the operating system or lock you out of it.

Patch - replacing a bit of code whith something designed to hack it. This patch may consist of a jump elsewhere in memory, or a breakpoint. Also something that pirates wear on one eye.

POKE - the process in which a single byte of memory is changed. Originally, games were hacked by one or two POKEs.

Protection system - A block of code which tags on the front of a game's loader and prevents anyone from accessing the code it is protecting. At least, that's what it's supposed to do!

Trace - looking through a block of code with the aim of finding something specific (such as an infinite lives POKE). This may be forwards, backwards, interrupt or stack trace.

Turboloader - a loader which loads in a file off tape at a faster speed than usual. This speeds up loading. The turboloader may be hidden by a protection system.

THE END

[C] 1992 NSA Publications. No part of this book may be copied, otherwise I'll send the Mafia round. Okay?