First Steps

Mark Hutchinson, Belfast

 

Issue 9

May/Jun 84

Next Article >>

<< Prev Article

 

 

I hope that the missing '=' signs in the last issue were not too confusing. These things happen in the publishing game. (Apologies also for spelling Mark's name wrong! Ed)

I would like to start this column by thanking all those people who wrote to me in Praise of ACE from English Software. No doubt I should have a copy. On the subject of the 410 (or 1010), I know that few of you get to see ANALOG magazine but if you have problems in loading your programs, try to get hold of the January edition (No. 15) which has a cassette recovery program by Bob Fine. Many is the time I have loaded a program only to find that the last few seconds of tape do not load. I have lost 10 or 15 minutes of time and gained in blood pressure! This program loads everything bar the bad frames and leaves it in memory. I must confess that I have not tried it, but it does look a godsend for cassette users.

Did you ever wonder why, when you pressed the ESCape key twice you get that funny little symbol? If you have read the manual, then you know that to print, say, an arrow, you need to press the ESCape key once then press CTRL and arrow. I have never seen an explanation for the ESCape symbol but it is quite simple. You press the ESC key to get the editing function of the character required. In the following examples press the keys shown between the inverted commas, do not type the words. To get the editing function of a key you must insert the ESC character, for example

10 PRINT 'ESC,CTRL-UP ARROW'

will show an arrow when you write it to the screen but will move the cursor up when you run it. If however you type the following

10 PRINT 'ESC,ESC,ESC,CTRL-UP ARROW'

you will see an arrow printed when you run it. In this way you can use control characters in graphics. The best way to do this is to define strings. As strings are re-locatable, i.e. the computer can shift them around in memory when necessary, you do not have to worry about protecting valuable RAM to store data. This subject is certainly worth a demonstration in a future issue. Hint.

Rod Reeves informed me that the book Your Atari Computer by Lon Poole gives a reference to saving files on a 410 recorder. This could be a boon to cassette users as long as they realise that they will not have the flexibility of files saved to disk. Perhaps Rod could give us a demo?

Mr. Fuller brought up a problem with re-defined characters. He was only able to get one colour for characters he re-defined. The problem is caused by not spreading the re-defined characters throughout the original set If for example you make your first player a capital A, the second a lower case A, the third inverse upper case A and the fourth inverse lower case A, then you will get four colours. The computer does not care about the shape, it is where the characters are in the set that determines the colour. Try printing the above letter A's in Graphics 1.

If you have a disk drive, try POKEing 3783 with an ATASCII value to change the character used for the DOS wild card (*). Locations 3818 and 3822 hold the range of legal ATASCII characters used in file names and by changing these locations you could include lower case, inverse etc. Do not forget that you still need a wild card. Any changes you make can be saved permanently with DOS option H.

Is a disk drive worth buying? If You have at least 32K and those hard to come by bits of green paper, then Yes. Disks are very easy to use, but understanding may take a little longer. Quite often there is a difference in tape and disk programs. Disks are easier to protect and often contain more scenarios, difficulty levels etc.

How about a few POKES to finish off? If you are tired of the same size of screen, try POKEing 559,43 for a much wider screen or POKE 559,41 for a narrow screen. Please note that you will still use 40 characters per line so a logical line will look quite strange.

Finally I mentioned in the last issue that a number of questions on graphics keep cropping up and as it is very difficult to demonstrate graphics on the printed page, Baug Software have put together a series of tapes for beginners which I hope will adequately answer many of the questions which arise.

I think I have finally caught up on my mail but don't forget that it is the mail that keeps a magazine going, so keep sending it and don't forget a Stamped addressed envelope if you want a reply.

Write to Mark at BAUG Software, P.O. Box 123, Belfast, N. Ireland, BT10 0DB

top