Broadcast Automating AtariProgramming WIMA with a 130XE.
By Mark Gierhart
As a result of network programming changes, management at radio station WIMA in Lima, Ohio presented our engineering department with a real challenge. We needed to resurrect our old automation system so it could handle local programming for six hours every night. And it had to be on-line in two to three months! The engineering department consists of only two full-time engineers, Dick Knowles and myself, which meant we had our work cut out for us.
As the first step, we examined our options. We could repair the outdated system which had last been in use several years ago, or we could design and construct our own system using the salvageable parts from the old automation unit. Either way, the time constraints would make it a difficult job.
After analyzing the existing system we determined that many of the control parts which needed repair were either no longer available or difficult to come by at best, and the time required to get the parts available would put us over our deadline. This left us only one option, designing a new system.
With the choice made clear, our task was still no easier than before. We needed to find a "brain" or controller for our system, and it had to meet several criteria. It had to be easy to use, reliable, and most important, cost-effective. This brain had to control several music tape decks, commercial carousel decks, voice tape decks and satellite network news feeds, all with little or no outside operator assistance.
The system would require some type of microprocessor controller to allow storage of program events and time schedules. Having had previous experience with the Atari 8-bit computer's capabilities, we elected to go with an Atari 130XE computer as the main brain of our automation system.
The Atari 130XE had all the features we needed for the project, including the low price tag. To complete the system, a disk drive, printer and several cartridges were included in our purchase.
At this point, we were ready to start working towards our goal, building our broadcast automation system using our 8-bit computer. My task was to write the software and design the computer interfacing to accommodate Dick's audio and switching designs.
Having done some programming in BASIC XE from ICD/OSS, I decided that would be the language to use for my automation program. BASIC XE gave me several powerful features I wanted, including the EXTEND command (which uses the 130's extra RAM), the FAST command (which speeds up the BASIC), and several variable functions which standard Atari BASIC doesn't allow.
I also needed the ability to access the clock output functions of the Atari 130XE, giving the program accurate time and date commands. I decided to try ICD's R-Time 8 module. With ICD SpartaDOS I now had access to both the time and date either formatted or unformatted.
I now started on the programming. First I had to find a way to get complete control over each of the audio sources needed for the system. Being in a somewhat high-noise, high-RF environment, I decided to use the Atari's built-in sound generator, using small, cheaply-constructed tone decoder interfaces.
Using a series of Atari POKE commands, I could produce just about any tone from 100hz to well over 10khz. The computer sends out the given tone, which turns on the tone decoder, closing its relay contacts to start, stop, or perform any other specified function on the tape machines. Thanks to the Atari's fine four-channel audio sound system, I was now able to control any outside source.
Now I needed a reliable means of interfacing the Atari with the outside world. I elected to use the Atari's paddle (joystick) ports. These ports have an internal voltage divider circuit which gives the computer a number values that vary with any change in voltage into the port. By placing a different resistance in each line of the interface, and using the PADDLE(x) command, I was able to distinguish each individual signal coming from the tape machines.
Once the interfacing was complete it was time to sit down and write the program. The program, which I call AUTOMATE, is completely menu- driven. Some of the special features of the program include an auto start/ stop mode, print to screen/printer mode, and an enlarged print mode. Also, all of the Atari's special function keys were incorporated into the program for ease of operation.
The R-Time 8 module functions were used constantly throughout the program. The Atari 130XE with this module is responsible for airing a network satellite news feed at the top of each hour. Also, this module makes automatic starting and stopping of the system at any given time a reality.
Another special feature of the program was the enlarged print mode. By pressing a single key while in the menu, the operator could bring up a Graphics 17 screen, enlarging all the menu text. I included this option in the software to aid a vision-impaired person working here at the station.
After about a month and a half of "late night" programming I was ready to hook AUTOMATE into the rest of the automation system. Dick had a well-designed audio/switching system ready and waiting for the program's completion.
Within a week, we had both the Atari 130XE and the audio/switching system up and running. To actually see the computer stepping through and playing each programmed event was a dream come true. The hard work and many long hours had paid off.
Future plans under consideration include interfacing the automation system with our accounting and billing department. This will allow direct billing and monitoring of the station's commercial inventory. The station already uses an Atari for inventory, word processing and scheduling.