Our Face is Red!
Dear Editor:
I recently received my first copy of Sync magazine and I was very pleased. However, I would like to point out a few things I found wrong.
1. Page 18—Nicomacus—Line 100 should read 70*a+21*b+15*c. As listed, this program correctly deduces numbers only from 7 to 104 or between 6 and 105.
2. Page 35—Multiplication Tables—Line 330 needs a semi-colon after A$ to run properly. Line 335 should have a comma instead of a period in the beginning of the print message.
3. Some of the listings require the use of spaces or changes in the print format in order for the messages to print out properly on the tv screen. Also, it would be a good idea to let your readers know if a listing will run in 1K memory. Some of your programs occupy so much memory, they will not run. For example; Page 36—Basic Accounting—As listed I could only enter up to line 2055 before I ran out of memory.
To be sure, the above items are only minor in nature, but I would appreciate hearing from you. All in all, I find the magazine to be an excellent one which I shall continue to subscribe to. Thank You.
John A. Sampson
College Point, NY
Four Tips for MicroAce Owners
Dear Editor:
These suggestions are based on my experience with the MicroAce.
1. Lacquer thinner and an old toothbrush are useful for cleaning solder flux from the PC board.
2. Changing R24 from 1K to 4.7K increases the sensitivity of the cassette input but still holds pin 2 of U11 close enough to ground for an adequate noise margin.
3. The crystal oscillator did not always start, especially when the computer was first plugged in. This problem was eliminated by a 100K resistor from pin 12 of U18 to ground (across C8). This is a leakage resistor which apparently draws off an accumulating charge on pin 12.
4. The keyboard input IC (U11) blew twice from a static charge while I was using the computer on a carpeted floor. This 74LS365 is replaceable by a 74LS367, which Radio Shack carries.
David A. Cromely
Channel 2 Interference Problem Cure
Dear Editor:
Enclosed is my check for a one year subscription to your SYNC magazine. Hope it is as good as your brochure states.
There are two items I’d like to relate about my experience with my ZX80. First, as you know, the computer is tuned to operate on Channel 2. Here in Atlanta, I live close to the station, and I could not display on this channel without a very objectionable amount of interference. I hoped there was some way to cure the problem, so I called the “technical rep” at Sinclair. His solution was-use the computer in the basement-find a room with metal all around-or move. Some help! Some old timers at work recommended I try inserting iron or brass in the tuning coil. By this time I had very carefully removed the cover from the non-adjustable tuner. Although the iron and brass did affect the frequency, it was not enough. A second idea was to very gently spread a few of the windings of the coil. Praise the Lord! It worked like a charm. I was able to to tune it to Chan. 3 with no problem at all. I closed up the unit and I’ve been on a good clear screen ever since. The second item concerned the cassette recorder. I set the controls, etc. just like the manual said. About 50% of the time I could not load from the cassette recorder to the computer. That is, until I tried the volume control setting at less than the maximum as recommended in the manual. In my case I can leave the setting on 7 and save and load with virtually no failures.
Well, thats it. Hope this info saves someone the frustrations I went through.
R.E. Henneberg