One of the reasons for purchasing my ZX80 was an article stating that Sinclair would produce silicon chips for other high-level languages such as COBOL, FORTRAN, and ALGOL. Does Sinclair plan to do this, or was someone just speculating?
Bill Peckenpaugh, Gualala, CA
According to Nigel Searle of Sinclair, there will be no Sinclair chips for higher-level languages. We would love to know where you saw the article, though.–SB
I notice that you use the term “Syntactic Sum” at the end of your published programs–what does it mean, and what usefulness is it to programmers?
Daniel Deadmore, Cleveland, OH
Syntactic Sum (Feb. 81, p.7) enables you to check your input with SYNTAX listings. In 4K machines, the technique counts up all character codes in ZX80 working space. 8K Syntactic Sum counts number of bytes used as well as character codes. Type your program in, run Syntactic Sum, and compare what you got to what we list underneath the program. If the two differ, you’ve made a typo.–SB
I have a stereo cassette player. When recording, I plug the ZX80 output into the left channel and a microphone into the right channel. I first give the program name on the cassette and then SAVE the program on the left channel.
Then, when LOADing from cassette, I leave the right speaker connected to my stereo and connect the ZX80 input to the other speaker output. I hear myself announcing the program, and the ZX80 alone hears the “gosh-awful noise”, as my wife used to call it. When cassettes are recorded this way, you can still use them on a regular portable cassette player.
Edward A. Goettman, Rochester, PA
I just recently constructed MicroAce‘s 2K kit and found two annoying bugs. The first problem, ineffective video drive to 74LS00 gate, I fixed by changing C12 (47pF disc ceramic capacitor) to 100pF.
The other problem, difficulty in typing some characters in from the keyboard, I cured by pulling up all keyboard columns with a 1/4-watt 10kΩ resistor to +5V. I mounted resistors on the MicroAce board’s foil side, one end connected to the anode of the diode, the other to a +5V trace running adjacent to the diodes.
No problems now. Thanks to Mr. Bill Clark and technicians at MicroAce for their help.
William Kresl, Elkhorn, WI
If one makes a hardware modification on a ZX80, how does that affect the warranty?
John M. Morrison, Moorestown, NJ
Hardware changes void the 90-day warranty, says Sinclair.–SB
Since the computer uses bit locale within 8 bytes to generate characters, is there some way to construct and display other unique characters or modify the print sequence so each pixel is not 1/4 of a character square but rather 1/64 of a square?
Tom Roseland, Riverside, CA
Yes, but not simply. The bits are stored in ROM, and we have not yet found a way to divert the display routine to look in RAM for data.
Using 4X or 8X high characters, you can create any shape you wish by changing the source of data from ROM to RAM. Just create bit patterns in 8 consecutive locations and change the PEEK address to read your location instead of ROM. See SON OF BIG CHARACTERS (Feb.81).–KO
Upon testing my 8K ROM, I discovered the same errors David Shulman described (July 81, p.8). I have sent for a replacement. My concern: will programs taped on the original 8K ROM work for the replacement ROM?
Stephen Levy, Bowie, MD
Yes. According to Sinclair’s Nigel Searle, the changes won’t affect what the computer understands, just what it does.–SB