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WIP: ULAPlus hardware implementationThis aims to be an "almost" plug-in replacement for the Sinclair ULA chip fitted in Spectrum 16K/48K/Plus machines. It comes in a form of a small PC…
... 100K gate FPGA, a 50MHz oscillator, and a small platform flash ... store FPGA configuration. An optional AD724 can be used to encode ... the modulator box (if the AD724 is included). Of course, RGB ... -
WIP: ULAPlus hardware implementationThis aims to be an "almost" plug-in replacement for the Sinclair ULA chip fitted in Spectrum 16K/48K/Plus machines. It comes in a form of a small PC…
... extra video output possibilities. The AD724 would be in that spot ... the FPGA, platform ROM, oscillator and AD724 as main components. The majority ... -
ZX-Uno prototype for saleThis is a FPGA based clone. You will receive the PCB and all the components unmounted. Mounting this PCB require advanced soldering skills because sm…
... , the main FPGA
[*]50MHz oscillator.
[*]Three voltage regulators.
[*]AD724, generates Composite signal.
[/LIST ... -
Harlequin clone...PCB manufactured!Using Chris Smith's detailed schematics and project notes from the Harlequin... a Speccy fan in the United States by the name of Don (Superfo) has de…
... AD724. Its oscillator does not start itself. After touching the oscillator pin the oscillator ... -
Harlequin clone...PCB manufactured!Using Chris Smith's detailed schematics and project notes from the Harlequin... a Speccy fan in the United States by the name of Don (Superfo) has de…
... AD724. Its oscillator does not start itself. After touching the oscillator pin the oscillator ... -
Harlequin clone...PCB manufactured!Using Chris Smith's detailed schematics and project notes from the Harlequin... a Speccy fan in the United States by the name of Don (Superfo) has de…
... problem with the PAL coder AD724 as follows:
While disussing ... I found that the PAL oscillator didn't start to oscillate ... -
Harlequin Rev. G - Composite video problem.What I'm about to describe I'm not experiencing it by myself, so the probable answer to any "have you tested this or that" question is no, I don't, b…
... AD724. It was found by experiment that on some boards the oscillator ... up. If the oscillator pin of the AD724 was touched after powering ... for any brand of the AD724 but it was found not ... -
VHDL specs for SpeccyI got it into my head that I should program a bunch of FPGAs and build a Speccy of my own, using designs from opencores.org (specifically the T80 cpu…
... memory, adaptive voltage and tuneable oscillator could be fun. Not to ... -
Spectrum 48k SeettingGot an issue 2 speccy on the bench that had a poorly ula, changed that, also changed tr4 and tr5 (had no oscillator) now it just resets over and over…
... tr4 and tr5 (had no oscillator) now it just resets over ... -
Unconventional way of diagnosing a faultHi everyone Some time ago I got a 48k Spectrum (issue 3B board) in a pretty bad condition. I believe the power supply transistor TR4 failed, causing…
... happens if you disconnect the oscillator from ULA?
Also ... -
AY LPT InterfaceI've found by my Friend an Old AY-3-8912 Chip last week. On saturday I have made interface for LPT for PC. And Plugin for EmuZWin. And now I have rea…
... and Working.. With 7404 als Oscillator and 7474 als divider. -
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'…
...
The solution: Another oscillator of the frequency you want ... 74LS629 voltage controlled oscillator, a 4MHz crystal oscillator and an ... sync with your accurate crystal oscillator.
And ... provide the 4MHz crystal oscillator circuit which is the ... -
ZX Spectrum 48K clone and test resultsHi! This is my first post, so, first of all, I'd like to say hello to the whole community! I am Alessandro Dorigatti from Italy and I'm developing …
... (512K, 128K, 512K), a 14MHz oscillator, and other useful hardware (you ... -
Problems with a gray ZX Spectrum +2Hello. First of all, thank you for receiving me on this forum. I'll try to help everybody as well as I can Said that, I want to do two questions abo…
... noise produced by the UHF oscillator). None fixed the problem
Faulty Interface one, IF1Dear all, as I have already mentioned in a different thread my IF1 stopped working for no special reason. I went through the service manual and chec…
... /> - I checked the 8 Mhz oscillator at pin 5 from ULA ...A 30th Anniversary ProjectHappy new year (belatedly...) So with the 30th anniversary approaching, I've decided to do a hardware project to celebrate it. Something hands-on (o…
... changing the frequency of the oscillator. The change in capacitance is ... controls a VCO (voltage controlled oscillator) which makes a square wave ...Revisiting Spectrum CPU clock regenerationWarning: This post will be a bit nerdy :-) Some time ago, I experimented with phase locked loop circuits as a possible way to regenerate the Spectru…
... soldering wires onto the 14MHz oscillator circuit we have only ... of an analogue voltage controlled oscillator being used to produce ... a stable and accurate crystal oscillator would be the master clock ... being driven by a crystal oscillator.
So now ...Improving Composite Output of 48K SpectrumI've been playing around with this Spectrum 48k I got inside a dK'tronics keyboard, because well I've already got two working other ones so why not..…
... wondering if the 4.4Mhz oscillator that drives the chroma carrier ... the output of the 14Mhz oscillator is, could this be a ...50 Hz / 60 Hz switch in Timex Computer 2068I'm not sure if this is common knowledge, I've certainly never read about it online, though it may be documented in Portuguese or Polish. There is a…
... is part of the SCLD oscillator circuit. So it's a ...ZX spectrum 128K + 2 (Grey one :)Hi all, I'm trying to revive a dead ZX 128K +2 (the grey one). The regulator was damaged and seemed to be feeding 7.8Volts onto the pcb. Yikes ! I…
... suspect it may be the oscillator transformer T1/T2 ( as detailed ... a way to breadboard an oscillator to measure it's coils ...Overclock the Z80 cpu to smooth out gameplay?Was thinking today of a Genesis/Megadrive mod I did a while back. It involved lifting the CLK leg on the motorola 68000 cpu (which in the MD, if I r…
... ) and adding a 10MHz crystal oscillator next to it and attatching ... and adding a 4MHz + crystal oscillator.
Wondering what your ...ZX-FPGA dev boardI've been sporadically working on this: [IMG]http://photo.alioth.net/tmp/spectradvi.png[/IMG] It's an FPGA dev board for the Spectrum. It uses a CP…
... also has a separate crystal oscillator, I suspect I'll use ...So for my first trick...I'm sure people have already used the AD724 or AD725 on other 8 bit machines, and i know the Harlequin uses the 724, but not seen anyone trying to us…
... people have already used the AD724 or AD725 on other 8 ... , bypassing the TEA2000 completely. The AD724 and AD725 can work directly ...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…
... resistor ?) would be a crystal oscillator of 1Mhz?The Spectrum In EuropeWhat are the differences between Speccys in Europe and the UK? ie would a British 48K work in France or Italy, and vice versa?
... ) and has a 5.5 oscillator, so works fine in the ... ). 'original UK' version has the oscillator tuned to 6Mhz for UK ... , taht You can tune the oscillator yourself (it has a little ...Spectrum musichello, I was wondering if anyone had released some kind of music sequencing software for the spectrum? if so, can anyone point me in a direction of …
... , because it modulates one sine oscillator with another. This makes for ... a very versatile oscillator, but it's hard to ...Spectrum musichello, I was wondering if anyone had released some kind of music sequencing software for the spectrum? if so, can anyone point me in a direction of …
... where the output of one oscillator (the modulator) is used to ...ObituaryYesterday my spectrum died :( Over 7 years of faithful service its finally gone to Silicon heaven. Rest in peace spectrum 48k+ Born sometime in 198…
... is the coil in the oscillator - and most likely means the ...+2a / +3 rgb csyncI want to separate the csync signal comming from the RGB port into vsync and hsync. Dose anyone have a circuit diagram, parts list etc of how to do t…
... you make a local H oscillator based on a TV sync ...+2a / +3 rgb csyncI want to separate the csync signal comming from the RGB port into vsync and hsync. Dose anyone have a circuit diagram, parts list etc of how to do t…
... TVs, where the local H oscillator is very imune to short ... H circuit has a local oscillator (either analog or digital type ...
