|★ APPLICATIONS ★ CP/M ★ CODING - ARNOR C ★|
|ARNOR C|Amstrad Computer User)||ARNOR C|Amstrad Action)||Arnor C macht Dampf!|ASM)|
A is for Amstrad, B is for Binary
COMPUTER companies sometimes generate a loyal following, as you are no doubt sick of hearing, Arnor has a special place in most CPC owners'hearts. This review is being written with Protext on a CPC664, in preference to an 80286 IBM compatible with a £450 word processing package, so they must be capable of doing things right.
C GAINS a lot of flexibility from being compiled. It was designed (a fact that newcomers to the language find difficult to believe at times) to work in a similar way to the computer itself, but expressed in a form that programmers could understand without them having to learn the details of each separate machine.
COMPOSING a C masterprogram takes time. With Arnor C, as with most Cs on most computers, the program goes through various stages on its way from brain to CPU. It starts out in a text editor (where it's called the source code), gets compiled to an intermediate form (the object code), and then gets linked up with various bits of machine code to form the final hunk of code that the computer runs (the executable image).
COMPILERS produce programs that can run by themselves. Arnor have produced a program that will turn your C program, once you've got it going and running in semicompiled form, into a stand-alone, fully compiled chunk of machine code. You can then distribute this to all and sundry, whereas the need for a runtime program limited the potential users of the semicompiled version to those who already had Amor C.
COMMANDS like PRINTF have to be identified. Every time you put PRINTF into a C program, the compiler remembers what it is you want to do, and leaves a marker there. It's up to the linker to find PRINTF in a library file, work out where it is and fill in the marker with a real address in the compiled program. But the linker usually includes the whole library in the final file, so you can end up with two line programs that link down to tens of kilobytes in length. C isn't designed for two-line programs . . .
COMPILED programs are big, even with the minimal library, you can end up with 13k or so of overhead on top of whatever program you've written. Silly for titchy progs, but once you get to about 30-40k of your program it starts to compete well with other options. And most of the functions in the full libraries are composed out of simpler functions from the minimal library, so you can always improvise them yourself, if you're desperate to do so.
CONFINING a program to the features which are available on all computers is often a shame, so Arnor C also has extra functions to make efficient use of the CPC's screen and other attributes. These extensions make for easier programming, but will cause problems if you try to move your program onto another computer. This process, called porting, was one of the things that C was explicitly designed to make simple.
CONFIRMED Arnor addicts will like the editor supplied with Arnor C it's - surprise - Protext. Well, it's "a full implementation of the program mode of Protext", and as such is up to the job of creating C source. It does lack a few features found on more specific editors, for example Vedit (the editor I use to create C source code on my PC) has automatic indent and bracket matching.
and now here it is again, all nice and neat
You might also see how useful automatic bracket matching could be, C lives and dies by its curly brackets... But there are features built-in to the editor which make such minor omissions seem, well, minor.
CONCURRENT editing means that you can edit two files at once, and allows you to copy blocks of text between them. This is massively useful, especially in C, when you often need to cannibalise old programs for useful bits that you don't fancy writing again. AC is much stronger than a mere compile command. It also links and runs the program, so during the later stages of debugging it turns into a nice environment under which the C freak can polish up his (I know of no female C freaks) creation. To a person such as I, used to skipping between compiler, linker and editor, scribbling down error messages on the back of the Guardian and losing my place, it is pleasant indeed. And it's all decently speedy, even on my minimal system.
C tends to generate lots and lots of disc files. As well as the source code you wrote, there's the object file, the link file, various bits like the libraries and the compiler and editor itself. As a result, although you can make it all work on a single drive CPC6128 (or 464/664 with extra memory, as used for this review), a second drive is definitely good for the soul. And PCW owners with a second drive and oodles of M: will be laughing.
COVERING the software is one thing, but trying to teach C is another. The manual does advise the beginner to get hold of and read several books on the subject before starting, advice I'd wholeheartedly agree with, although the books you'll need are often very expensive.
C is unusual in the CPC field, as mastering it gives the programmer a readily saleable skill which he can apply in the commercial sector. The same program that you write for Arnor C and your 464 will port across to a multi-hundred thousand pound IBM mainframe (but it won't have the graphics).
For £50 it has to be worth every penny. In typical Arnor fashion, they've taken their time and got it right.
Rupert Goodwins, Amstrad User October 1987
L'alinéa 8 de l'article L122-5 du Code de la propriété intellectuelle explique que « Lorsque l'œuvre a été divulguée, l'auteur ne peut interdire la reproduction d'une œuvre et sa représentation effectuées à des fins de conservation ou destinées à préserver les conditions de sa consultation à des fins de recherche ou détudes privées par des particuliers, dans les locaux de l'établissement et sur des terminaux dédiés par des bibliothèques accessibles au public, par des musées ou par des services d'archives, sous réserve que ceux-ci ne recherchent aucun avantage économique ou commercial ». Pas de problème donc pour nous!
CPCrulez[Content Management System]
L'Amstrad CPC est une machine 8 bits à base d'un Z80 à 4MHz. Le premier de la gamme fut le CPC 464 en 1984, équipé d'un lecteur de cassettes intégré il se plaçait en concurrent du Commodore C64 beaucoup plus compliqué à utiliser et plus cher. Ce fut un réel succès et sorti cette même années le CPC 664 équipé d'un lecteur de disquettes trois pouces intégré. Sa vie fut de courte durée puisqu'en 1985 il fut remplacé par le CPC 6128 qui était plus compact, plus soigné et surtout qui avait 128Ko de RAM au lieu de 64Ko.