So you can't write Machine Code. Suddenly that's not the barrier it used to be: PAT McDONALD takes the wraps off a new package.
Bored with Basic, you sit there, drumming your fingers on the desk and wishing the programs you've spent half a lifetime perfecting didn't take the other half to run.
Very sad. There must be many with this problem of programs that just don't get a look in because they're in Basic. 'You could always write in machine code," some clever dick says. "Ha!" you reply: I'm not a megagalactic Skol drinking alien. And even if I was then I stili probably couldn't understand assembly language.'
What would be really good is if you could take all your Basic games and convert tnem to machine code without messing about re-writing them. It probably wouldn't be that easy, but there's got to be a better way :han pure binary gibberish...
Enter the dragon
Pandora is a compiled version of Basic designed to take the sweat out of programming.
To write a program using it you first type out the relevant code into an Ascii word processor (Brunword - late version - and Protext are fine, Tasword isn't). If you don't have u suitable word processor, Swift have thoughtfully included a small program that stores the data as Ascii.
The Pandora Basic language is not the standard Locomotive variety built into the CPCs. Instead it's a sawn-off version lacking in certain areas (such as string and text ban dling) and built up in sprite graphics handling.
Sprites, of course, are an integral to almost every computer game, but as the manual says, you can ignore them if you all you want is a faster version of Basic.
The sprite handling is of a reasonable standard, though, and certainly offers exciting possibilities to the games writer.
|Adventures in history|
There have been other programming utilities for the would-be professional (ie money-earning) programmer. The Laser Genius series (Laser Basic and Laser Compiler) fulfilled much of the same purposes as Pandora. But they did not contain a separate dialect of Basic, relying on Locomotive and lots of RSXs to deliver the goods. This approach has the virtue of simplicity but the vice of consuming lots of memory.
There have been others, but none really up to the standard of Laser Genius. One area which did produce a flurry of programming aids was the writing of adventure games created with PAW, The Quill, Incentive's GAC and Camel Micro's Genesis. The problem was that, although they produced professional looking programs, games written with them all looked very much alike.
Pandora's advantage is its superior flexibility. Expect to see professional programs produced using it before long.
You can have up to 32 sprites driven along independent courses at the same time. 48 different frames can be held in memory at once, and different banks of sprites can be loaded when required.
One drawback is that sprites cant overlap very well onscreen flicker is quite horrendous when this happens - and they also cant go in front of any background graphics. Still, it's early days yet, with this being only version 1.00...
|How it works|
What makes compiled programs faster than ordinary interpreted ones? One of the main reasons is that all of the jumps to the various routines are precalculated.
Take the command goto 1000. A compiled program already knows exactly where line 1000 is, and can go there straight away.
An interpreted program has to sit down and calculate where to go. An immense waster of time is a looping routine.
If the program has to work out where to go each time, time is wasted unnecessarily. Compiled programs don't have that problem.
Pandora has a memory map that starts at 43000. Thus you can utilize from 40200 to &2FFF for your own purposes -data, perhaps, or a Basic program.
The compiled program can be 8K long, a fair but not overly generous allowance. You can however always use overlays - sub-programs loaded individually if a program is too big to fit in memory complete.
Screen output streams are all disallowed - so no text windows. In fact, in version 1.00 text handling is a little primitive, relying on printing characters one at a time, though increased speed partially makes up for this.
If, as intended, Swift release an updated version of Pandora able to run independent machine code routines -possibly stored in memory below the compiled program -this product can be transformed.
A routine that needs speed, such as a new longer lasting graphic frAme command (see The Look, AA41) could be added without fuss.
Extra text, disk and sound handling could be added too. Perhaps a user club may be born to keep track of all the different patches, tweeks and short cuts, as happened with Incentive's Graphic Adventure Creator.
men you have your Ascii file you must run it through the compiler program. This goes through the code looking for errors, and if it doesn't find any it turns al". the Basic commands into a machine code file that can be run independently of Pandora.
Although not as fast as 'the real McCoy, a compiled Basic effort is faster to write in order to get programs finished quickly.
So what sort of program could you write with it? Well nearly anything is the disappointingly vague but uncompromisingly accurate reply.
The only tricky area is when you try to drive the sprite routines past their limits. What you get is superfast sprites that flicker. You'd be writing something along the lines of Silkworm before this got to be much of a problem.
Another limitation is the lack of a real meaty data area. OK, so you can use the bottom end of memory (see the box) but you're not going to squeeze a DTP package into it.
Thai leaves spreadsheets, art packages, finance planners, utilities, adventure games, and of course arcade games.
The standard of finished game that can be achieved using Pandora is admittedly unlikely to reach Mastergame status: on the other hand, budget games wouldn't be a problem.
If you played around with overlays, it would be perfectly feasible to create a mega disk-only game
- Swift Software began by offering the Arnor range of utilities on disk and ROM. They've just completed a 10,000 word, 1,000 main subject heading Thesaurus/word finder, Keyword. It too costs £29.95 - look out for the review in next month's AA.
- Next release is a disk of sprites and sound effects for Pandora, expected to cost £10 tape/£15 on disk.
- And later in the year there's a similarly priced compilation of the best games created using the program - with royalties being paid to the authors. So get cracking now!
- By the way, get your order for either Pandora or Keyword in before the end of July and you receive a free calculator/watch!
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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.