SYNC at the Drawing Board
Our theme section this issue is “SYNC at the Drawing Board.” This selection of articles illustrates some of the techniques that can be used to generate graphics displays. If the number of manuscripts we receive means anything, producing a graphics display is among the most popular challenges of computer programming.
All of us can draw a picture on paper (some better than others, of course). We envy those who can draw real pictures with a few movements that seem so effortless. Now the computer has given us all another tool for making pictures and the challenge of mastering the display screen.
Simply filling the screen with a graphics display is one of the first programming efforts. Such a display can be produced through a program involving a random element such as several of our “Try This” entries have done. These brief programs can fill the screen with constantly changing patterns. However, we have no control over the display once the program begins running. The greater challenge is to produce a display that shows what we want whether a picture or some kind of graph or design. The ultimate display is one that the user can interact with and that will modify itself in response to user input. The games with moving graphics are prime examples of this type.
Graphics are fun for their own sake. To be able to control the graphics capabilities to produce hi-res displays is the programmer’s reward. In order to develop displays with moving graphics and high economy in programming, we need to learn something about machine language programming. However, many are also interested in using graphics as part of a larger program to display data, liven up programs, provide a challenging game, or just have the fun of creating a display.
The programs in our theme section illustrate how mathematical formulas can be used to provide graphics, how to get the smooth graphics that resemble movie or TV pictures by the use of machine code, and how to use such programs as subroutines within larger programs. We hope that these articles, along with our “Just for Fun” entries, will challenge your imagination and give you some tools for your own programming.
Theme Sections Coming
Our next issue will feature “SYNC in the Home Office.” Other projected themes include “SYNC on the Job” which will show some of the ways Timex/Sinclair owners are using their computers for their jobs, “SYNC at the Concert” which will show some of the musical capabilities, “SYNC at the Arcade” which will put together some arcade type games.
Other theme sections will depend on the availability of articles to support the setion. So if you have a possible article to support one of these themes, we want to see it.
The ZX81 BASIC Programming Manual
If you make a reference to the manual that you received with your Sinclair ZX81 or 8K ROM in any article or correspondence sent to SYNC be sure to specify the edition. There are four editions of the book available now: the first and second British editions and the first and second American editions. There are some differences.
SYNC Is Growing! You Can Help!
The first nine issues of SYNC gave readers a magazine of 48 pages plus covers with about 30-35 pages of editorial and 12 to 15 pages of ads. Volume 2:4 jumped to 80 pages; Volume 2:5 to 100 pages. This issue has 124 pages showing increases in both editorial and ad content.
To maintain this size magazine we need your help in two ways:
1) We need articles and contributions from authors. So if you have an article of possible interest to SYNC readers, we would like to take a look at it. If you have been thinking about writing something, drop us a note telling us what you have in mind. We will tell you whether we would like the idea developed and in what direction to increase its usefulness to our readers. If you missed “Writing for SYNC” in SYNC 2:1, send a self-addressed stamped envelope for a copy. This will help you put your article together. If you are interested in writing reviews, see p. 110 below.
2) We need advertisers. If you have a product, please contact Karen Musmeci, our new Advertising Sales Manager (see the contents page for details). If you have bought a product whose manufacturer or distributor has not advertised in SYNC, please plant a suggestion.