This is showing off the 560Z and 430B boards. The 560Z Z80 is digitizing output from the Heathkit signal generator and displaying it on the Tektronix 602 vector monitor. Software is doing a falling edge trigger. You can see jitter in the vertical values due to the trigger logic taking a couple instructions so sample point varies. I demonstrated the limitations of the tracking ADC. As I turned up the frequency the sine wave would become a triangle wave and the amplitude would drop.
On the right at the same time I was running on the 6502 a mugger game my brother wrote in BASIC when he was in high school. You are playing a mugger in a city.
I was planning to show loading the Z80 demo from cassette tape. It failed to load too frequently so I loaded the 560Z demos from my laptop instead. I built the 430B and replaced belts and bad IC in the cassette player for this show so problem could be either. The cassette player is one my wife used. It would be better if it had a counter to make having multiple programs on a tape easier.
The switch on the front of the Challenger selects if it uses the video board or serial port. That was a modification the original owner did. Most of the software I have uses the video board. The 560Z software needs serial.
Photo by Commodore Z
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