-
Spectrum +2 grey RF removalHi everyone. If I were to remove RF output from a +2, just intending to keep Composite video out from TEA2000, then all the components that make t…
... the TEA2000 completely with an AD724 or AD725 based circuit. [/quote ... am not familiar with the AD724/725 IC's. Maybe on ... -
Spectrum +2 grey RF removalHi everyone. If I were to remove RF output from a +2, just intending to keep Composite video out from TEA2000, then all the components that make t…
... am not familiar with the AD724/725 IC's. Maybe on ... ]
No problem. The AD724 and AD725 are quite easy ... -
Auto-fire circuit based on IC 555Greetings! Spanish magazine Microhobby once wrote an article explaining how the auto-fire circuit worked on a joystick and the interface requireme…
[quote="Renegade;54626"]The blue rectangle reading 1MHZ (just below 10K resistor ?) would be a crystal oscillator of 1Mhz?[/quote]This is a 1M ohm resistor.
[b][i]Mark[/i][/b] -
ZX Nuvo 128..Hi There, I have built the ZX Nuvo 128 by Superfo, but it has a problem. The machine is working, but the video signal is completely bonkers. I've …
... (HQ48K) vs parallel (Nuvo) resonant oscillator circuit. -
ZX Nuvo 128..Hi There, I have built the ZX Nuvo 128 by Superfo, but it has a problem. The machine is working, but the video signal is completely bonkers. I've …
Specialized crystal drivers like the 74LVC1GX04 have been around for over 10 years now and that an oscillator driven by a 74HC04 is instable has been known for much longer. -
ZX Nuvo 128..Hi There, I have built the ZX Nuvo 128 by Superfo, but it has a problem. The machine is working, but the video signal is completely bonkers. I've …
... years now and that an oscillator driven by a 74HC04 is ... -
ZX Nuvo 128..Hi There, I have built the ZX Nuvo 128 by Superfo, but it has a problem. The machine is working, but the video signal is completely bonkers. I've …
... frequency jitter in a 14MHz oscillator (Harlequin 128). Substituting the chip ... -
ZX Nuvo 128..Hi There, I have built the ZX Nuvo 128 by Superfo, but it has a problem. The machine is working, but the video signal is completely bonkers. I've …
... frequency jitter in a 14MHz oscillator (Harlequin 128). Substituting the chip ... -
Issue with TV signal + Inductor Coil (16K Issue 2 Speccy)Hello guys, I just got a 16K Issue 2 Speccy from eBay. It was sold as not working so I knew there would be some work needed before it's working ag…
... exact frequency of the main oscillator (used by the ULA for ... adjust the frequency of the oscillator used to generate the colour ... -
Making sound using the BEEPER in AssemblyI had a look at the the documentation but it doesn't make sense to me. To make music just the beeper all I have to do is send ones and zeros to one o…
... will need to simulate an oscillator, using a [i]counter[/i ... -
Making sound using the BEEPER in AssemblyI had a look at the the documentation but it doesn't make sense to me. To make music just the beeper all I have to do is send ones and zeros to one o…
... , one could just calculate one oscillator, and derive the others from ... -
Non-repetitive RNDHi guys) Perhaps, some of you already encountered a situation, when one needed a set of [b]unique [/b](pseudo-)random values, say, from zero to 25…
... bit is that the two oscillator / multivibrator circuits don’t synchronise ... -
Finding a good (UK) external switch mode power supply for the basic 48k and 128k ZX SpectrumsThis idea has probably "done the rounds" by now . I think I have heard about it a bit late . This thread with look at replacing the original "heavy l…
... this DC (controlled by an oscillator) and feeds it to transformer ... -
Need a new keyboard for Issue 2I've dug out my old Spectrum's today. My +3A and +2 grey are both working perfectly. However, my old early Issue 2 keyboard was replaced with a SA…
... should use a24 MHz crystal oscillator with it . And then it ... it work anyone? Why an oscillator? -
128K refurb.... What is the best way?Here's the latest Spectrum I got... Finally got a Toastrack... Not sure if it was good value ( around US$100 ). [img]https://os.blackice.com.au/us…
... the z80. Check at the oscillator. 17.27MHz. That doesn't ... -
128K refurb.... What is the best way?Here's the latest Spectrum I got... Finally got a Toastrack... Not sure if it was good value ( around US$100 ). [img]https://os.blackice.com.au/us…
[quote="cj7hawk;975204"]No clock on the z80. Check at the oscillator. 17.27MHz. [/quote]
Hold on. If the CPU is getting no clock, then the problem might be the ULA. Check Pin 36. You should see a steady 3.5 MHz clock signal there. -
128K refurb.... What is the best way?Here's the latest Spectrum I got... Finally got a Toastrack... Not sure if it was good value ( around US$100 ). [img]https://os.blackice.com.au/us…
... /> I played around with the oscillator varicap and after that found ... a signal at the Z80. Oscillator is still 17MHz, but 3 ... -
Introduce yourself[SIZE=3][FONT=Comic Sans MS]This is the thread to stop by & introduce yourself.[/FONT][/SIZE]
... the low profile 14MHz crystal oscillator is missing.
I ...
