Ah yes, Dynaco. They used to be a very hot ticket in stereo pre-amps. My dad taught me to solder when I was in Jr high school (grade 7 or 8 ). In 11th grade, my friend and I were all about stereo - speakers, amps, blah blah. He decided he would buy a Dynaco pre-amp for me to build. Toughest thing I had built. Looking back, it was a great kit with great instructions. As I remember, specs were very close to McIntosh. Probably got that wrong, but...
Heathkit fuzz pedal? Great die-cast case with wrinkle finish. Problem was it did not provide a volume boost with fuzz (then only used for lead riffs), but rather the volume was cut significantly.
How about H89 computer? All in one, 48k ram, 2ghz 8080 processor, 90k single sided hard-sectored disks, green on black 80x24 screen communicating with the CPU at a blinding 9600 baud! All that for a measly $2,500! Add $200 for the extra 16k ram. Couldn't afford the $300 for the soft-sectored controller. The terminal board and the CPU board came assembled. You built the power supply, all the high voltage supply for the CRT - basically everything in the hard-foamed molded case. I chose C/PM over HDOS. Wee ha.
Immediately I had a problem with the thing just resetting itself randomly. Heathkit got it at least three times, checking the power supply (good we had a store nearby). They'd put a test pattern on it and leave it sit, waiting for a fault. Weeks at a time. None there. Get it home, and within 5 minutes, bang.
Must be the house power. Bought an expensive power strip. Nope. Fought with the power company - finally they came out and put a "dot recorder" on my power panel - measured voltage every five seconds or so, and had a pen and graph paper where the pen would drop and make a dot on the paper. To them, voltage was fine. Nearly a straight line. Of course they then said their grid was not designed for clean power for computers. Try an isolation transformer. More big money (for me) - well over $100 anyway. Zip. Still a problem. Back to Heathkit. No ideas. I started thinking... C/PM loaded at a different address than HDOS - which was what they were testing with. Memory? Heck with it. This called for the shotgun approach. I got some contact cleaner, pulled each chip on the motherboard one-by-one, CPU, memory, every single chip, dipped the legs into the cleaner, and reseated the chips. No more problems!!
I let the techs at Heathkit know how I solved the problem, and suggested they change their testing protocol. Tech was moving on! Hot-rodded it with 19.2k baud comm between CPU board, and got a kit for a plug-in 4mhz Z80 processor, and two half-height floppys. Still have it. Couldn't part with it. I shudder to think how much I've spent on computers over the years...
frank
