ZBasic Forum

Vic, I've been doing something that can be adapted to your proposed use. It doesn't involve a cell phone, but it gets data from point A to point B via radio. It's actually pretty common in amateur radio circles and is called packet radio. Look up packet radio in Wikipedia for a broader explanation. ...

I thought I'd try measuring the frequency on a ZX-24 and check on the stability of the oscillator vs outside capacitance to the crystal. I measure 14.74518 MHz with a likely error of 10-20 Hz since I didn't do more than a casual calibration. The loop was inches away from the crystal, so significant ...

Don, If you are in posession of a digital readout shortwave receiver, you might be able to measure the clock frequency with great precision minus significant coupling to the circuit. As a ham radio operator I've often put a small loop of wire across a coax and connected the other end to the receiver...

Vic, I scanned the net for a long time a while back to find a device that took a PC keyboard and painlessly converted it to a simple ASCII serial data stream. Multilabs makes this device ( http://www.multilabs.net ). While you can conceivably do this with a ZX-24, why bother with the complexity of r...

Vic, Wikipedia has a pretty decent explanation of pressure and height and provides equations to compute pressure if height is known. You will have to solve the equations for height since you are dealing with a known pressure. Check http://en.wikipedia.org/wiki/Atmospheric_pressure for the informatio...

Wow, trips down "memory" lane. I wrote my first program in 1964 on a Bendix G-21 at Carnegie-Mellon University(then Carnegie Tech). That started the computer addiction and I wanted one at home. For me, that became possible in 1977 when I bought an IMSAI 8080 kit. A PerSci linear motor dual...

Somehow I knew you were going to ask me why I was using bounded strings, Don. I went back to the documentation on structures, the latest addition to my program on its way up from BX-land and found the statement that caused me to start using bounded strings. From the documentation: The allowable memb...

Let me provide more information. I confirmed that whether optimization is on or off it still fails the same. I ran a list on the program with and without the concatenation line. Here are the two listings. The listing with no concatenation (makes sound) ===== file: midtest.bas Option StringSi...

Sanity check or compiler/vm problem? The following code excerpted from a much larger program seems to illustrate the improper growth of a bounded string beyond its declared length. Appending some spaces to AckNum causes it to alter Dummy. This is using the latest VM and compiler on a ZX-24 Option St...

You are correct, Don, about the default array base being zero. I misread the phrase in the Option Base description: Note that it is not necessary to use this directive to define 1-based arrays. The syntax for array definitions (see page 13) allows you to specify any base value that you wish for each...

Thanks, Mike. I'll use the workaround and keep on truckin.

Dennis

Thanks for taking a look, Mike. No, I haven't set any other base commands. It was my understanding that arrays were based at 1 by default, but I included a setting of 1 in the code to be sure. I also compute 44 bytes as the length of the structure. If I change the upper bound it grows by that amount...

I must be overlooking something about array allocation. An excerpt from a much larger program was compiled separately and it appears that an array structure is allocated more space than requested by adding an extra array element. The program is: Option StringSize 40 Option Base 1 Structure Msg 'Mess...

Great suggestion, Don. That should save some processor cycles for the next task.

By the way, the program is chugging along great with and without optimization.

Thanks again.

Dennis

Don, I was pretty sure it was a firmware/compiler fault, but there's always some self-doubt about how sharp I am when a problem persists. Thanks for homing in on the problem. Guess that ups my score to about 3 system errors uncovered over the last year or so. The chip and its associated software are...