MAKING YOUR TRS-80 TALK

by Ron Stoloff

[Written June 18, 1982]

This is, at the least, an article about an esoteric topic: using BASIC in a computer forty years ago, but, in essence, it describes what computing was like in those long ago times. It also describes how at the same time it was so easy to tinker with computer hardware and software was at the time and how difficult to find resources.

Some months ago at the TRS-80 PACS meeting we discussed the various ways to make speech with the TRS-80. We heard several types of speech synthesis but they were often just barely recognizable.

I had been wrestling with a program on the AR sound – a phonics lesson intended for first or second graders that I had promised to try to adapt for Larry Charry so the kids it was intended for would be able to handle it – the instructions were such that if the kid could read the instructions, he didn’t need the lesson. Our esteemed leader (IBM-1) [That’s HAL Brown for those who don’t get the reference. Check out 2001.] told me there was a way to control the cassette recorder via program – the only problem was he could remember only the command “OUT” – not the number.

Not being able to wait, I rushed home to my computer and sought to find the magic command. I knew it was somewhere between 0 and 256 so I set up a loop, put in a tape, turned the volume up and left the room. Some time later I heard the sweet tones of Star Wars and knew I had found the Holy Grail. It was a simple thing to discover the various ins and outs of this control but basically it works this way:

10 OUT 210,10 ‘turn on

20 Do what ever You want

30 GOSUB 1000

40 OUT 236,15 ‘turn off

1000 FOR I=1 to 1000:NEXT I:RETURN

For a little more sophistication, you can send it to various length delays via a gosub so that the recorder is on long enough to accomplish your deeds. To do this RUN the program and attach the recorder but just put it on play with no tape. RUN the program and see if you have enough time to say what you wish.If you don’t have enough time, send it to a longer delay until the time is sufficient. If the time is too long, do the opposite.

There are some weird things that happen when running this: whenever a CLS is given the recorder stops, so it must be started up again. The large size characters are also affected in strange ways and places. It should be understood that not only 10 and 15 will affect the recorder but others as well and some of these don’t bother the large characters the way 10 does. For example try l8 instead of 10 and the large characters are left alone.

Fine, so you can DO it, but what can you do WITH it? Besides instructions, you can give spelling tests. You see, having the screen print “Spell CAT” is something of a giveaway. What you do is have the tape give the words, a sentence or whatever, stop, the kid types in her answer, the program compares it to its data list, responds, yea or nay and the recorder gives the next word. I tried this and it works quite well.

Have fun!