Here is a program that demonstrates a simple yet effective way to get analog information (data) into your ZX81/TS1000/TS1500 computer, with a minimum of additional hardware. Also included are various plot and display routines so you can get visual and printed output of your acquired data. Along the way it will show you various “tricks”
VDAQ – A Data Acquisition Development Program Read More »
The easiest way to connect your computer to a monitor is to simply take the composite video signal from pin 16 of the ULA (“SCL” chip). Since this isn’t capable of much power delivery, it will only work in the “high-impedance” input setting. If your monitor doesn’t have a Hi/Lo-Z switch, open the monitor and
A Video Reverse Board Read More »
So far in “The Custom T/S,” I’ve shown you how to overcome problems with all three of the little inline jacks on the left side of your computer, with fixes that handle trouble with power input and tape-recorder functions. There’s only one other connection (other than the rear edge-connector) left to cause any grief; the
Veni, Vidi Video, Vici Read More »
One of the advantages of building a ZX81 from a kit was that you got a schematic with the manual, and you gained some insight into how the machine worked as you put it together. It was evident, for example, that the computer was missing some memory from 8K to 16K — an area transparent
If you have a VOTEM, or if this article talks you into buying one, here is a simple modification which will extend the board’s utility further, and allow you to start LOADing a program from tape, flip a switch when the loading bars appear on the screen, and walk away; when the program has loaded,
Votem Cassette Controller Read More »
Here are a couple articles that introduce you to control applications for the T/S computers (ZX81, TS1000, TS1500) with a minimum of effort and (best of all) at reasonable cost. Before we control something with a computer, we usually need some way of getting information back to the computer; ie, to control an oven, the
It was interesting to see in page 10 of the 1:1a issue of SyncWare News, a joystick circuit that is a variation of a circuit which I have been using since I customized my Sinclair ZX81 in the summer of 1982. When I moved the ZX PCB in a large keyboard case, together with a
An Improved Joystick Read More »
Onward to replacing our good old wall-plug power supply with something more substantial. You have several ways to go, and I’ll try to touch on some of them here. BE CAREFUL as in this project we’ll be dealing with “raw electricity.” Not to scare you off, but “follow the rules” about insulating connections, observing polarities,
Un-interruptable Power Supply Read More »
Yes, folks, there’s plenty of room left in even your tiny “stock” case to include re-chargeable BBU INSIDE THE COMPUTER. This makes it immune even to pulling the plug! My 16K machine has the BBU circuit, exactly as above, “under the hood.” I must say that using AA cells makes things rather tight, and it
Now we’ll make some changes and additions to “El Cheapo BBU” that will allow us to use rechargeable “NiCad” cells to provide back-up protection and short-term (up to an hour or so) portable use of your ZX81/TS1000 machine. This approach uses your good old T/S wall-plug supply to power the computer WHILE KEEPING THE BATTERIES
The Re-chargeable BBU Read More »
The circuit shown is the simplest scheme possible to provide power-down protection for your ZX/TS. You just need a battery holder capable of holding six “one-life” batteries (AA, C or D size), a few silicon diodes (GE531, Radio Shack 276-1141, or other 50 PIV, 2A silicon rectifier) and an on-off switch. An enclosure, some zip
Battery Back-up The EI Cheapo BBU Read More »
