Some years ago, I needed to keep real time on a BASIC Stamp microcontroller. I used a circuit based on a 32.768kHz watch crystal and a 4060 CMOS logic 14 stage counter chip. The microcontroller polled the output of the counter using an I/O pin. It used this as the time reference and then the program kept track of seconds, minutes, hours and days. It ran for weeks and the time was fairly stable with not much drift.
If you wanted, this could also be done on a ZX81 / TS1000. You would of course need some extra circuitry so that the Z80 CPU could read the counter (address decoding and control).
The schematic and other details (for the BASIC Stamp) are in this PDF.
Mark
Pause Function - useful for a Clock?
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Re: Pause Function - useful for a Clock?
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer being good this year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer being good this year.
Re: Pause Function - useful for a Clock?
Erik already wrote such a program .....mrtinb wrote:You need some external hardware for a clock.
Maybe you could use ZeddyNet to sync the clock with an Internet server.
Siggi
My ZX81 web-server: online since 2007, running since dec. 2020 using ZeddyNet hardware
http://zx81.ddns.net/ZxTeaM
http://zx81.ddns.net/ZxTeaM
Re: Pause Function - useful for a Clock?
My ZX81 web-server: online since 2007, running since dec. 2020 using ZeddyNet hardware
http://zx81.ddns.net/ZxTeaM
http://zx81.ddns.net/ZxTeaM