First, I would like to give the address of QZX, the Journal for Amateur Radio and Sinclair Computers. We neglected to give this important information in issue 1/5. Contact them at:
2025 O’Donnell Drive, Las Cruces, NM 88001
They have been around for three years now for those of you who are ham radio buffs.
Tony Gomez, [address omitted], [phone number omitted], has a board that converts the Compusa disk interface to drive the DEC disc system.
There has been a ton of response to our first issue of volume two. Thank you. With round two of the questionnaires in, Product Reviews are weighting quite heavily towards the number one choice that people read about. I draw two conclusions from this. One, you want to know what is available and worthwhile, and two, you have been either burned by bad software or baffled by it. We need reviewers. We have received some response from our last plea, and we have several reviews “in the pot.” We will have your fair share of reviews next time.
We have received numerous letters (thank you), and we will be printing what we have room for as time goes on.
Dear Editor—I must write and tell you that Basil‘s article has given me some real satisfaction. It was the motivation to renew my interest in Machine Code, that this article brought me…After struggling with Toni Baker‘s “Mastering Machine Code on your ZX81“, I eventually realized that in a statement like DIM (A$(22,32), that A$(0) has no meaning. Anyway, I look forward to Basil’s future articles.
Roy E. Brann, South Pasadena, CA 91030
First, A$(0) is a throw back from the ZX80 4K ROM. Toni wrote that book quite some time ago. Basil replies, “Thanks for your letter of encouragement. I too struggled with that book. It tried to do too much in too little time. I may lean too far the other way. I am trying to cover every agonizing step, although I don’t want you to lose interest. This text was originally a book, in which the reader could pick his own pace. This serialized rendition may go slow. Bear with me. I will try to include a nice little utility in each ‘chapter.'”
Dear Editor—Please let me know who can fix my ZX81 if it breaks and tell me where I can get spare parts for my machine just in case.
Kingsley Langenberg, Waukegan, IL 60087
Parts? ZX81’s have parts? The only part you can’t get easily, is the ULA. It is available from Timex Computer Corp., Little Rock, Ark., for $12.00. Most other parts can be bought from JDR, Dokay, Radio Shack, etc. (Check the back of a Byte magazine.) Look around at local flea markets. I have purchased brand new TS1000’s in boxes for $.99!! The box is worth that much. Don’t hesitate to open the back and “play around” with it. It is a great machine to “LEARN” on. For problems, start with the power supply. Is it warm? NO? Replace it (9VDC 1 amp). Leave the machine on for 15 minutes. Is it warm over the 2, 3 keys? NO? Replace the 5 volt (7805) regulator (Radio Shack). Do you have a display? NO? You have a problem. Crash with 16K ram hooked up? Right away? possible bad ram pack. (I recently bought a 16K ram for $9.95) After 10 minutes? Maybe a wobble problem, weak power supply, static electricity problem or dirty edge connector. Check for VERY hot power supply, TV with a lot of static from the screen, etc. Won’t LOAD or SAVE? Possible noisy RAM pack, check connectors and only use ONE connector at a time. Also, check the diodes near the LD/SV jacks. Keyboard row won’t work? Check and firm up the ribbon connector. Check the diodes near the ribbon connector. Still have a problem? Try swapping chips. The SGS Z80 may be weak. Still not running? You need some help. By the way, what IS the problem?
Is there anyone out there who would repair these little black boxes that we all hold so near and dear? Let us Know.