-
Help, How to RGB to VGA Connector on +2A ?Hi, How would I go about converting the RGB output connector from ZX Spectrum +2/A to VGA type of connector. I found this device [url]http://www.am…
... A/D converter by too high input voltage - therefore there are the ... -
Challenging the orthodoxy - Composite modWell, what's brought this on is two things: firstly I composite-modded an Issue 4S board this weekend in preparation for the Vintage Computing Festiv…
... Base needed no external bias voltage etc., etc.! I never doubted ... /> As calculations show this relatively high AC load of 75 Ohm ... -
So you need to double (or triple, or quadruple) the clock speed...No particular reason for posting this, other than I was looking at an eZ80 evaluation board that does this, and that jogged my memory of a project I'…
... somehow. And watch the output voltage levels: normal logic levels may ... say you need low & high very close to supply rails ... -
So you need to double (or triple, or quadruple) the clock speed...No particular reason for posting this, other than I was looking at an eZ80 evaluation board that does this, and that jogged my memory of a project I'…
... (and of course its voltage input high enough impedance not to load ... filter enough to make its voltage fall significantly, and thus reduce ... well before IORQ goes back high.
[quote]
... say you need low & high very close to supply rails ... -
So you need to double (or triple, or quadruple) the clock speed...No particular reason for posting this, other than I was looking at an eZ80 evaluation board that does this, and that jogged my memory of a project I'…
... ]that[/I] much), and high level output voltage is ~3.5V. Just ... -
So you need to double (or triple, or quadruple) the clock speed...No particular reason for posting this, other than I was looking at an eZ80 evaluation board that does this, and that jogged my memory of a project I'…
... ]that[/I] much), and high level output voltage is ~3.5V. Just ... of your board is disastrously high (I think at single digit ... -
Schematics for loading amplifier?I'm interrested in making an external portable amplifier in order to be able to load speccy games using an mp3 player. I looked in the internet but c…
... the high impedance coil to the spectrums input you have a voltage ... -
New stereo audio board for fitting on AY chip - interested?Hi, I developed a small board that fits on the AY chip inside 128K ZX Spectrums: [IMG]http://www.benophetinternet.nl/hobby/vanmezelf/stereo_audio.j…
... would be better to avoid high frequencies from the audio output ... (if loudness is set very high).
4. To distribute ... two channels adds not the voltage. And therefore each of the ... -
New stereo audio board for fitting on AY chip - interested?Hi, I developed a small board that fits on the AY chip inside 128K ZX Spectrums: [IMG]http://www.benophetinternet.nl/hobby/vanmezelf/stereo_audio.j…
... signal noise. The circuitry has high impedance (about 10 kOhm and ... its last state also without voltage on its coils. So if ... -
Loading from audio source via laptopI am having trouble loading my Spectrum tapes with my tape player - it is connected to my laptop, and I have tried the microphone and headphone socke…
... signals are a bit too high for a mic input of ... line will supply a DC voltage for an external microphone which ... the signal is much to high comming from tape for the ... problem maybe the undesired DC voltage on one of the input ... -
Schematics for loading amplifier?I'm interrested in making an external portable amplifier in order to be able to load speccy games using an mp3 player. I looked in the internet but c…
... " trick. It would increase the voltage while increasing the source impedance ... input impedance of spectrum is high enough. So one transformer alone ... -
Broken ZX Spectrum? :(Hi! I bought a 2nd hand ZX Spectrum half a year ago. It worked perfectly fine when I first tried it. I put it back in its box which it was sent in, …
... .1uF - 1.6F
Maximum voltage: 3-600
Accuracy: Terrible ... ", stability "poor", leakage "good" . comments, high capacitance, polarized, small, low inductance ... a modern switcher is very high frequency which allows you to ... -
Spectrum +2a / +3 SCART LeadsEvening all, Over the past week or so I've tried two different Spectrum RGB SCART leads from two different Ebay sellers, on a Spectrum+2A and a Spec…
... blanking serves for high-speed (hence low impedance, low voltage) switching between ... -speed, high-impedance (kOhms), and takes up to 12V input voltage. If ... -
Spectrum +2a / +3 SCART LeadsEvening all, Over the past week or so I've tried two different Spectrum RGB SCART leads from two different Ebay sellers, on a Spectrum+2A and a Spec…
... blanking serves for high-speed (hence low impedance, low voltage) switching between ... -speed, high-impedance (kOhms), and takes up to 12V input voltage. If ... .. 12V on pin 8 (a voltage lower than 8V is detected ... -
128 port hardware patchReading the ULA book has reminded me of something. In The Spectrum Hardware Manual (Adrian Dickens) there is a hardware patch to allow free use of al…
... wind up with some intermediate voltage all the time. What ... will make the OR gate high.
* A P- ... transistor is ON, holding IORQGE high. If the OR gate ... new transistor can pull IORQGE high. If A0 = 1 (and ... 's already pulling IORQGE high so it doesn't matter ... -
128 port hardware patchReading the ULA book has reminded me of something. In The Spectrum Hardware Manual (Adrian Dickens) there is a hardware patch to allow free use of al…
... amplifiers, MOSFETs instead are voltage amplifiers (virtually no gate ... flows is controlled by voltage). However this distinction is ... br /> * MOSFETs have very high input impedance at the gate ... (since the inputs have such high input impedance).
128 port hardware patchReading the ULA book has reminded me of something. In The Spectrum Hardware Manual (Adrian Dickens) there is a hardware patch to allow free use of al…
... a concentration problem here.... The voltage levels of A7 are undetermined ... , just like the low voltage on IORQ is. Which makes ... and my scope measures the high state on A7 as 4 ... on it, the gate threshold voltage varies from transistor to transistor ...Recapping your SpeccyHas anyone ever done it? I have several vintage amps, tuners, cassette decks that have been recapped. So just wondering are there many on WOS who ha…
... the +2 (I get higher voltage at high currents - they remain cold ...Mute switchOn a standard 48K machine, would it do any harm to fit a mute switch into one of the sounders connections ? I mean by 'harm' switching it on / off w…
... will stress TR7 with a high current condition.
I ... ) with the switch on, the voltage at the base will be ...Oscilloscope Speccy ProgramHi all, I remember very well in the old days when my Speccy was my single computer (around 1992) that I have had an oscilloscope software. This uses…
... the Spectrum as being a voltage ranging from -1 to ... as either 0 (-1 voltage) or 1 (+1 voltage).
voltage into values ranging from -32768 ... to 'Y' axis for voltage and the 'X' axis ... band pass filters at high sampling rates as 32 ...Simple & Portible means to boost PC Soundcard Line Out?Hi Guys, My older computers were very good at driving a real spectrum's ear socket via their Line Out or Headphone socket. My new Dell's sound card…
... of "level filtering" that allow high amplitude signals and block lower ... some help on resistor and voltage levels.
Cheers guys ...Possible design fault in +2A/+3 power pack. Fix?It's the second time a +3 power pack ceases to work when I make a short while using the scope to diagnose a +2A/+3 computer. And it's the second tim…
... under normal operation. Once the voltage between the base of T1 ... junctions shouldn't be high. It will be high temperature that kills ...Amperage drastic reduction in a rubber 48KWell, I am now with the approach of a drastic reduction ZXSpectrum amperage. As a first step would change the Z80 processor for other (Z80C). Unfortu…
... supporting ztx853 100V collector-emitter voltage, a continuous current of 4A ... circuit, or if a peak high (as may occur just when ... 7 ", its consumption is very high, they are art displays, tactile ... , high resolution, etc ... if I search ...Loading games with cassette adapter - no PLAY requiredAfter several encouragingly successful experiments with the use of cassette adapters commonly used to connect a multimedia player to a cassette-only …
... that when the volume is high enough - boosted through as simple ... cassette adapter that induces enough voltage in the cassette heads to ...Microdrive using simple coilWhile listening to my iPod using cassette car adapter I came to idea - why not doing the same for the microdrive? Anyone ever tried that? Do you thin…
... stuff and set signals to high and low. You could fit ... there's still place for voltage regulation (resistors?) and coils. But ...Variable resistorI have a problem with my speakers - the treble is much much too quiet in comparison to the bass. Or you could say, the bass is much to loud for the r…
... resistor in series in the high power part of the circuit ... dissipating a lot of heat (high current flows through it) which ... to a nominal maximum rms voltage generated by the amp of ... sure its power rating is high enough.
Power dissipated ...Variable resistorI have a problem with my speakers - the treble is much much too quiet in comparison to the bass. Or you could say, the bass is much to loud for the r…
... resistor in series in the high power part of the circuit ... dissipating a lot of heat (high current flows through it) which ... to a nominal maximum rms voltage generated by the amp of ... sure its power rating is high enough.
Power dissipated ...Which support do you use for loading software?Hi all, It's been a while since i came here... Nevertheless, a question came into my mind... Which support (hardware) do you use for loading into s…
... probably only become apparent on high-speed protocols such as used ... power the output at a high enough level to get through ... AA, AAA or other low-voltage battery then the chances are ... consistent output power needed for high-dynamic range tape data. I ...RGB cableI constructed an RGB cable to my +3 as per schematic on page 14 of this document here: [URL="http://mts.speccy.cz/doc/128_rgb.pdf"]http://mts.speccy.…
... /> You could generate a suitable voltage from the 12v easily using ... with a high input impedance. If so generating the reference voltage need ...
