★ APPLICATIONS ★ PROGRAMMATION ★ BREAKPOINT ★ |
| Breakpoint (Amstrad Action) | Applications Programmation |
This latest Melbourne House utility is a real oddity, and no two ways about it. It's a monitor a tool for debugging machine code programs - and there's nothing unusual about that. The point is, however, that it's just a monitor: nothing more. If you want to program in machine code, you really need an assembler. This enables you to write your program in easy-to-leam assembly language rather than the completely unmemorable hexadecimal numbers that make up machine code itself. There are many assemblers available for the Arnold, and they're mostly around the £15 mark in their cassette versions. Once you've got the hang of programming in assembly language and started writing lengthy, complex programs, you'll start to find some unpleasant bugs cropping up. Unlike Basic, you'll have no error messages to help you and the escape key is unlikely to stop your program. Worse still, bug-ridden machine code programs tend to go beserk, often destroying all evidence of what the problem actually was in the first place. It's this kind of problem that monitors are intended to help you solve. They're so called because they let you 'monitor' the running of your program and (hopefully) stop it just as things start to go wrong. That way you can see what you've done wrong, kick yourself for your own stupidity and then put your program right. Sounds useful, does it? Sounds like every Arnold-owning machine code programmer is going to rush out and buy Breakpoint! Well actually, they aren't. If you've got an assembler you're not going to bother buying a monitor, for the simple reason that you've already got one. As a general rule, assemblers and monitors are sold together as an 'assembly language programming system' or similar. I'll stick my neck out here and say that I can't think of one assembler commercially available for the Arnold that doesn't come with some sort of monitor. A monitor is considerably less useful than an assembler, and of very little use on its own. Clearly Breakpoint would need to be quite remarkable to sell under these circumstances. Equally clearly, I'm afraid, it isn't. In use it's a fairly ordinary single-step/breakpoint monitor. You can run your program one instruction at a time, you can run it slowly while keeping an eye on it, or you can set it off at full speed with a breakpoint to stop it at some crucial moment. Breakpoint can also show you areas of memory and allow you to make small modifications to it. You can search memory for particular numbers, you can save chunks of code to tape or disk. All functions are controlled by two-letter commands, entered at the command line. All very well, and what it does it does proficently, but that is what you would expect from any such package, and with most you would get an assembler as well. Considering that Laser Genius, reviewed in our July issue, offers a better monitor and an assembler for the same price, Breakpoint cannot be said to offer value for money. The sample reviewed was pre-production, though the manual was very reasonable, but unless Melbourne House add an assembler on production versions we cannot recommend it. ?
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