★ APPLICATIONS ★ A peek into Pandora's Box ★ |
| Swift Software - Pandora (Amstrad Action) | Swift Software - Pandora - a Peek Into Pandora's Box (The Amstrad User) |
If you played around with overlays, it would be perfectly feasible to create a mega disk-only game. Well, for a short month, we take a short break from the thorny subject of assembly language. Our esteemed Editor had two programs from Swift Software for review. Swift Is a UK software house, one I hadn't heard of. Nice of them to provide material, so the least we can do Is "give It a go!" The first package is called KEYWORD, defining Itself as The Dynamic Word Finder for home and business use. Inside the rather unusual cover is one disc and a user guide. The latter Is printed on heavy stock, is short and to the point. 1 installed the program, following the directions, and It performed as promised. KEYWORD Is an RSX which can work with other programs. Tlie user guide refers to the situation of installing (he RSX and working with Pretext in ROM. As this is not my working procedure. I could not try It. As their RSX takes up a great deal of space and needs their "dictionary" disc (side two) in the A drive, it does seem somewhat limited for many users. The process of working with Pandora is a lot like that of assembly language under CP/M, albeit easier I tried loading Tasword after installing the RSX and. as suspected, was unsuccessful. Not a great deal of user memory Is left after Installing the utility. 1 did prove that the RSX installation, followed by loading a small BASIC program, still allowed "dictionary" access - so I assume the operation to be bug-free. KEYWORD is essentially an electronic version of a thesaurus like a computerised Roget's. As an aid in composition and writing, it would have a definite use. The user guide remarks that the program was written by a professional Journalist for his own use. Obviously, he uses Protext In ROM. With over 10.000 synonyms and antonyms In the dictionary and over 1.000 subject headings - KEYWORD can be handy In roughing out a draft In the pencll-and-paper mode. I did note a couple of spelling errors In the User Guide, so perhaps its use could be recommended to Swift... They make a point of saying the program is not copy protected, and hope users will do the right thing. I think they deserve credit in this regard. A clever pirate can rip anything off. given time. All too often, software houses arc paranoid about potential financial damage, and end up with products the legitimate user cannot use flexibly, if at all! Now on to the real offering for the month. The second Swift package is called PANDORA. On opening the "envelope" containing the disc and user's guide, one notes the same packaging technique as for the other product: a heavy card stock with double, self-locking tabs, probably designed by an Origami enthusiast. The contents are one disc and one manual, the latter a small offering in a stapled binding. A quick perusal of It leads to a "swift" conclusion that the software people ought to farm the writing out to a professional. Obviously, they are saving money on overheads. The cover ostensibly takes the place of the title page, and the table of contents springs out at you when you open the booklet. The first page of text, right hand side on turning the page, is page two. A minor quibble, but definitely not the way real publishing is done. The major gripe Is one that is all too common in high-tech books: no index. Thus, finding specific references Is a case of flipping back and forth, back and forth. What is Pandora? (That's their introduction phrase, by the way). They let you know it's "up to 200% faster than in Basic." speak of Sprite handling commands, and say that "all Pandora programs are semi-compiled before they are run." What they don't tell you precisely is what it Is. They rabbit on about how it works, differences from the BASIC you're accustomed to. and about how to drive It. It's sort of n turbo mode In software. Wow. you say. will It let me write arcade style flames In Basic that run as a challenge to do something more than a snail? Maybe. On the disc, you'll find 14 files when you do a CAT. Some of these are lor a demo program, and also there are two games - simple, but they exhibit the end result of Pandora's twlcc-as-fast BASIC. Handing out software for evaluation by magazines Is surely a good Idea • but presentation Is a major factor In the eyes of the reviewer. The manual refers to I*andora Version 1.00. whilst the review disc was Version 1.01. The differences? Well, this letter looked at the table of contents for any mention of the "editor" program on board the disc. None. The manual says the Pandora system Is Just one program made up of two separate parts, the Compiler and the Supervisor. Well, there Is a compiler file on the disc, according to CAT. And an editor file: no super. Guess it's really part of the main system. As an example of clear writing, the book leaves something to be desired. All. well. Being one of those pessimistic souls. I loaded the "disc" program and listed It. Lo. It loads Pandora. CAT didn't see It. so I booted up CP/M and used the SDIR utility to Inspect the directory for the real stoiy. Two system files. EDITOR.BIN and PANDORA.BIN of 5K and 18K size respectively. Next step was to run up the README program, which gave the difference between the manual Instructions and the current operation. Incidentally, they remark that Version 2.00 Is due out In November 1989. Let's hope the sale copies have an up-to-date book along with the disci The newer version will offer a sprite editor for all screen modes; a music designer and sequences, with envelope and sound effects creator, and other goodies. Upgrades are available at a modest cost. You'd be advised to use your word processor to format and print this text, for you'll surely need It. And you have to have a word processor, for this Is the key lo writing Pandora programs. The book says so. Later, however, they contradict themselves and tell you how you can use Pandora without a word processor. Aha. this Is the purpose of COMPILE.BAS. Essentially, this program pre-processes Pandora style BASIC statements, created as DATA statements. Somehow. I don't think I'll bother doing It that way. You may. however wish to Inspect Appendix IV. which describes the technique. The process of working with Pandora Is a lot like that of assembly language under CP/M. albeit easier. You write a "source" file using the word processor. The first major difference that will strike you is the lack of line numbers. So. how do you do a COTO, that command oft sneered at by so-called professional programmers? Simple, you use labels. Now. not only do the source files have to be straight ASCII format, they must not have any Invisible word processing format commands within them, else the operation will give you error messages. Using the Pandora variants of Locomotive Basic, as well as the additional commands for sprite handling and animation, you write a new style of BASIC file and save it to disc. You load Pandora, compile the source, and then you can run it You'll agree that It seems similar to CP/Ms ED. MAC and HEX approach. ...frequently you'll feel like throwing the manual against the wall. Pandora programs can exist In stand-alone mode, or can be used from within conventional BASIC programs. You might be tempted to save an existing file with the .A option and handle the ASCII text in your word processor. It would probably be easier to start from "square one". In my estimation. With all the variations from Locomotive BASIC, no line numbers AND new commands, adapting an old program would be time consuming, to say the least. The biggest limitation of working with this package Is the opening message once Pandora Is loaded: System installed with 7822 bytes freeBefore trying to work with It. you'll probably run out of patience in trying to understand the manual, and load up a game, as I did. The demo, "birds", simply gives you a screen of bird-like sprite flapping around. Ho hum. Well, how about the games? There's a "coke", a simple shoot-em-up and "game" (original, eh?) which is like a poor man's version of Asteroids. One wonders. whilst looking at the red and white can one is expected to shoot in the first little gem. if the soft drink manufacturers were consulted. "Came" is obviously included as a bad example ... it smells like every poor arcade game ever encountered, and even Includes a few bugs, like the occasional inadvertent debris left on screen. But If you want to be a "sprite cowboy", then this is a good model of poor programming to work from. Besides. Swift offer a free competition, mentioned In the README file, which could earn you a royalty on a good game! They Intend to produce a compilation disc of user's games: If you want to "see your name in lights", give it your best shot. The start address of any Pandora program is always &3000; yet the book states the first line of a user's BASIC program should be: 10 MEMORY &1FFF. If you think this is a misprint, think again. A perusal of the (obsolete) memory map in Appendix III says the compiled program resides in 2000 2FFF. with the Supervisor above It. In addition, other data like sprite descriptions and variables and arrays are stored In upper memory, also. All these overheads make it clear why there's little room for your BASIC program. Obviously. If your source is too big. it won't fit into the area provided by Pandora. Despite the Appendix with copious error messages described. I could see no discussion of what happens If the compiled code grows too large. Surely, some indication of an Impending diabolical situation must exist Shown above Is a sample of "game.src" from the disc. Just to let you know what you're In for. There, whata lotta fun! The first thing 1 discovered about their .SRC files Is that they have TAB characters embedded, which Tfesword thinks are block markers. After some time in fumbling around with the manual. I decided to have a bash at one of my short old programs. I loaded the file and resaved it using the .A option. Then I proceeded to erase the line numbers and modify the text to the format Pandora wants. Three times Into Tasword to correct a minor mistake, then clear the machine and reload Pandora. I finally got tired of this and abandoned my attempts to be an instant games master. The first lurk Is that Pandora variables are single letter names from a to z. The values range from -32768 to 32767. Say. this Isn't Forth. Is it? [There's also a stack - two. in fact: data and return.) There can be up to 13 single-dimension arrays, a through m. and taking the form a#z. A maximum of 128 subscripts per array is allowed. No string handling facilities exist, though one can print text to the screen with the TEXT command. Input Is limited to numeric variables. There Is. however, a GET command which can be made to accept ASCII values, and store them character by character In an array. Well, you don't need all the bells & whistles In an arcade game, do you? Essentially. Pandora is an abbreviated form of BASIC, with minimum facilities. The sprite designer Is convenient, and incorporates an animation capability. Thirty-two sprites can be created and manipulated. Sound generation has also been catered for, and the 2.00 version will have a music editor. If you want to design your own arcade games. Pandora is an adequate beginning. Be prepared to bum the midnight oil while you're writing your masterpiece, though. And frequently you'll feel like throwing the manual against the wall. Don't say I didn't warn you!
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