NOTE: T-S Horizons and the author assume no responsibility for damages arising out of the use/misuse of these articles. The reader must understand that any modification suggestion here is to be taken at the reader’s own risk.
METAL PAPER SOURCE
I am looking for thermal printing paper for my ZX printer. This thermal paper is the silver metal-coated kind. The TS 2040 thermal printing paper is incompatible with the ZX. Do you know any supplier and/or computer/electronic store that sells ZX type thermal printing paper?
Rufino Hilario
Passaic, NJ
First off I would like to say, that this paper is not the thermal type but electro-static, and you were right, in that thermal paper is incompatible with your ZX printer. Instead of heat sensitive paper like the TS 2040 uses, the ZX printer paper is black with a metal oxide coating over it. When the ZX printer prints, it passes a current through the paper, which vaporizes the metal coating, leaving the dark surface behind. Gladstone Electronics is the only supplier I know of. For a current price quote, you can contact them at the following address: Gladstone Electronics, 1585 Kenmore Avenue, Buffalo, New York 14217
( Integrated Data Systems
Toronto, Ontario M4M 1P3
Phone (416)466-5571
Also carries the metal paper. Editor)
JDM
ZX 81 PROBLEM
I have had a ZX81 since September, 1982 and have used it off and on ever since. I have now begun using it much more. I have a 2040 printer, byte-back modem and a 16K ram pack. The last two or three days, I have been unable to enter information into my computer and onto the screen. When I push down on the membrane keyboard nothing happens. If I take out the power supply plug and leave it off for a few minutes, and then plug it back in. I am able to enter a few commands, then it fails again to accept my commands. It is as though the membrane has gone out. What do you think is the matter? Could this be due to a lack of a heat sink? Is this serviceable and who services ZX81’s at this time? Would it be cheaper just to buy another?
Ken Hatfield
Richmond, Kentucky
The first thing to try is to remove your modem and rampack from the computer and test the computer to see if the problem still exists. If the problem has gone, then suspect either the modem or rampack is defective. If the problem still does exist, then I feel that your computer has a bad Sinclair Logic chip. As to the servicing of your computer, your best bet would be to buy another, for the price has dropped below the twenty dollar mark. See issue number 10 page 6 for one supplier. One final note, the fact that your computer will accept input when you first power up, but then fails, rules out a defective membrane keyboard.
KEYBOARD PROBLEM
I do need help! Keys H, J, L, ENTER, B, N, M ., and SPACE won’t function on my TS1000, and all the other keys work, except functions, because the ENTER-FUNCTION key doesn’t work. I checked the ribbon cable from the keyboard to the circuit board and none of the connections are touching ground. I would appreciate any suggestions you might have.
Guy H. Nicholson
The problem sounds like, one of your ribbon cables is not making good connection to the computer. To correct this, remove the ribbon cable which has eight wires, form its socket. Leave the cable with five wires in place. Now inspect the end of the cable that you removed, for tears. If it is torn, trim off the end just above the tear. After checking the cable and fixing it if necessary, carefully re-insert it back into it’s socket. Now test the computer, by putting it back together without the screws, and trying all keys. If all keys work now, put the screws back in, and your back in business. If the keys still don’t work, or others have stopped working also, try re-inserting the cable again. Repeat this several times if necessary. If you are still unable to the keys you listed working, try replacing the two diodes marked D7 and D8 and the top side of your computer, near the keyboard sockets. For replacement diodes, Radio Shack sells these in a package of 50 for $1.98. The part number of this package is: 276-1620. When replacing these diodes, make sure to get the correct polarity.
JDM
This concludes the letters for this month. If you have a question or problem, please write me, and for a speedy reply, enclose a self addressed stamped envelope.
T/S Help and Information
John Marion
HC 63 Box 650
Greenup, Kentucky 41144