What purpose does Syntactic Sum serve? If you can’t type NEW without deleting it, how do you replace a lengthy program? Line by line?
Gene Hammond, Carmel, CA
We wrote Syntactic Sum to help avoid typing errors when programs are transcribed repeatedly. Some of you have commented unfavorably on program errors in SYNTAX. We understand your frustration; we suffer the same frustration in trying to print perfect programs. Syntactic Sum will help both of us by providing a quick check for typing errors. To replace a lengthy program, just load a new one from tape.–AZ
Readers who constructed the eavesdropper circuit may have noticed annoying hash lines on their TV screens when monitoring their tape recorders. I found that even though the metal experimenter’s box shields the circuit, the earphone itself and its cord cause interference. Unplugging the earphone from the circuit box solves the problem. Other objects seem to cause interference for my ZX80 and Sampo TV, including my paper hole puncher, a metal file box, and a stack of cassette tapes.
Colin Alexander, San Francisco, CA
To reduce eavesdropper (Dec., 80) interference, you can also wire a 10 nF ceramic disk capacitor across the earphone leads at the resistor end. The capacitor provides a path for high frequencies inside the box so they don’t cause interference.–AZ
No parts layout information or schematics were supplied with my ZX80. It would be helpful if you would include this information in future issues of SYNTAX.
Joe Whiteman, Culver City, CA
To get a free ZX80 schematic, write Sinclair Research at 50 Staniford St., Boston, MA, 02114. Request the 4 page technical manual, which includes the schematic and instructions for a direct video monitor.–AZ
In previous issues you listed vendors of existing and planned peripherals but neglected to publish addresses. Don’t be a namedropper, how about addresses also?
Mel Routt, Safety Harbor, FL
Here are the addresses of companies mentioned in SYNTAX:
Innovision—D. Thornburg, Pres.
P.O. Box 1317
Los Altos, CA 94022
Voicetek—C. Georgiou, Pres.
P.O. Box 388
Goleta, CA 93017
Herbach & Rademan, Inc.
401 E. Erie Ave.
Philadelphia, PA 19134
Interface Technology
P.O. Box 383
Des Plaines, IL 60017
I found 2 programs requiring 8K ROM in your January issue. It also indicates Sinclair is currently unable to offer the 8K ROM. Is the 8K ROM available from another source? If not, why are you providing ZX80 owners with programs we are unable to use?
Eugene A. Cozzi, Barre, VT
No, the 8K ROM is not available from another source. We wrote the 8K ROM programs in December for the January issue while we had an 8K ROM prototype. We were told by Sinclair that you would be able to get 8K ROMs around the first of the year. Thus we gave you programs to use your new ROMs right away. To bring you the latest news each month, we consult our sources just before press time, when we found out the ROM was delayed.