-
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'…
... wire to the 14MHz clock that drives the ULA... so I think ... their nature synchronized with the master clock. A single D-type flip ... kept in sync with the master clock.
The method: ... it gets ahead of the master clock, the phase comparator changes the ... -
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…
... of the 112MHz master clock short - making the clock slightly faster for ... are the 3.5MHz clock as the ULA generates it internally, and ... the clock after contention. ... in perfect sync with the ULA only about halfway across ... -
My attempt to restore the CPU clock signalI know Winston has already got this, but I can't see any thread with details about it. Only wanted to share my (still early) results. I'm not taking…
... me a ininterrupted clock signal, filling the gaps where ULA stops it ... in sync with the internal ULA and the CPU, without relying ... /> input wire mclk, // 28MHz input master clock
input wire cpuclk_in_n, // 3 ... -
Real 60Hz NTSC 48K ZX SpectrumNot a 3rd party mod. The joystick mod was added by the user, but the board and the computer is exactly what was sold in Chile, South America. We migh…
... group says that the ULA isn't different from ... can be true. The ULA generates the interrupts of which ... NTSC Speccy involves: correct ULA, correct master clock (14.11MHz for NTSC ... , 14MHz for PAL), correct colour burst clock ... -
Real 60Hz NTSC 48K ZX SpectrumNot a 3rd party mod. The joystick mod was added by the user, but the board and the computer is exactly what was sold in Chile, South America. We migh…
... can be true. The ULA generates the interrupts of which ... also now know that the ULA used in these machines ... NTSC Speccy involves: correct ULA, correct master clock (14.11MHz for NTSC ... , 14MHz for PAL), correct colour burst clock ... -
Things I'd ask Chris Smith if he would give an interview about his book and researchGiven your current knowledge about the ULA interns, knowing what technology was capable to do those days, and knowing what people then and now would …
... was created for the 5C ULA, (the 6C has more capacity ... was not used.) The 5C ULA was amost completely filled, so ... be made synchronous with the master clock and propagation delay was deliberately ... Altwasser. So a cost effective ULA was chosen, and the design ... -
What paging scheme is the "standard" for 128K models?Sinclair implemented an arrangement so that even numbered pages are non-contended, and odd numbered pages are contended (quoting from memory, haven't…
... :-)[/quote]
True :-) The master clock is 17.735 MHz, the ... 128K uses. Thus, the CPU clock is 3.575 MHz and ... to probe anything on the "ULA" of this machine requires first ... figure out which signals this ULA generates and what pins they ... -
DIY AY for 48k schematicHello! I can't seem to find a diy schematic for attaching AY to 48k so it gets 128k compatible sound. I see offers to sell ready made devices, but n…
... 8. This clock signal is generated by the ULA and is ... either take the clock off the ULA direct, or find ... being synchronized with the CPU clock).
(Explanation ... to some sort of master clock. The idea is the ... by the time the master signal comes back. I ... -
SPECTRA New from Paul FarrowLooks good! Read about it [URL="http://www.fruitcake.plus.com/Sinclair/Spectrum/Spectra/SpectraInterface.htm"]here[/URL]
... 48K have a less robust ULA than the 128K (the ... to be more 48K damaged ULA's and hence, more ... very helpfull to have the master clock (35MHz) available at the ... to keep the external ULA in sync with the ... a PLL to synthetize the master clock would work here, as ... -
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…
... to work with the replacement ULA. Chris Smith tells me that ... 16/48K ULA, except for these points:
- The master clock is 17 ...
- The PSG clock is generated within the ULA, as half the ... clock frequency of the CPU ... -
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…
... ;652737]That's true. 128K ULA are essentially the same as ... 16/48K ULA, except for these points:
- The master clock is 17 ...
- The PSG clock is generated within the ULA, as half the ... clock frequency of the CPU ... -
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…
... is the master clock for the Spectrum clock regeneration digital PLL ... connector is from the ULA, before it is amplified ... This output from the ULA has rather slow rise ... CLK output from the ULA so it is in ... volts. (Actually, the ULA's signal never actually makes ... -
SPECTRA New from Paul FarrowLooks good! Read about it [URL="http://www.fruitcake.plus.com/Sinclair/Spectrum/Spectra/SpectraInterface.htm"]here[/URL]
... to operate (sync timing with ULA).
The SPECTRA manual ( ... to regenerate the 3.5MHz clock and use this to remain ... therefore know exactly where the ULA thinks the electron beam should ... -of-3.5MHz crystal controlled master clock and enough FPGA resource for ... -
SPECTRA New from Paul FarrowLooks good! Read about it [URL="http://www.fruitcake.plus.com/Sinclair/Spectrum/Spectra/SpectraInterface.htm"]here[/URL]
... to regenerate the 3.5MHz clock and use this to remain ... therefore know exactly where the ULA thinks the electron beam should ... -of-3.5MHz crystal controlled master clock and enough FPGA resource for ... -
Speccy 48K grey screenGot a issue 2 48K speccy as part of a job lot on ebay, tested it and apart from a duff membrane it appears to be working. However the screen is a gre…
... [I]tweaks[/I] the master clock for the ULA (14 MHz) - better not ... ]bends[/I] the color burst clock frequency, IIRC this is where ... -
Issue 4A repair attemptI think I need some help. I have a nice Issue 4A main board here, which does not give out any video signal. I checked some voltages (the ones that se…
... components etc., if the ULA's master clock is running and the video ... an oscilloscope to check the master clock is running and then look ... a video output from the ULA. If there is, I'd ... -
Weird 1982 Copyright message after cap change.Hello All, As mentioned before I had a busted Issue 6 48K Spectrum+, one of the capacitors had leaked, and trashed the keyboard membrane ribbon. Us…
... from the clock signal, which comes from the ULA. The ULA uses a ... 14MHz crystal to generate the "master" clock.
Weird 1982 Copyright message after cap change.Hello All, As mentioned before I had a busted Issue 6 48K Spectrum+, one of the capacitors had leaked, and trashed the keyboard membrane ribbon. Us…
... from the clock signal, which comes from the ULA. The ULA uses a ... 14MHz crystal to generate the "master" clock.
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…
... good.
Regarding the ULA crystal frequencies, these come from ... (CPU clock cycles per line) * 4 (master clock cycles per CPU clock cycle)
ULA crystal frequency. 15.750 kHz ... a PAL or NTSC ULA from any of them.Miracle Systems RGB monitor interfaceUpon doing some reading of the book [i]The Complete Spectrum edited by Alan Scott[/i] I found a reference to this RGB interface for the Spectrum whic…
... the master clock, which in a ZX Spectrum is the existing ULA. Don ... 't forget, the ULA controls the Z80 ... both the Z80 and the ULA.
Nowadays you may ... keeping in step with the ULA inside the Spectrum.
48k Spec with composite video mod, screen adjustment possible?I've had a 48k Speccy with a composite video mod for a few years now, and although it works perfectly otherwise, the screen isn't centered correctly …
... timing is fixed inside the ULA chip. The only external part ... the crystal that the ULA uses for its master clock timing.
Converting PAL +2b to NTSC[B]Hello my fellow WoS'ers[/B] I have a strange request for your knowledge and advice. A chap in the US would like to use a Spectrum +2B, however w…
... /> Thats to say changing the master clock as such giving the spectrum ...You know how the 128K was faster than the 48K Spectrum?Regarding how the Spectrum 128K ran at 3.54 MHz rather than the 48K's 3.5MHz, was this difference enough to be an advantage? If not, then surely Sinc…
... 3 implemented a higher clock speed but could still ... br /> Some other MHz clock could be used such ... a multiple of the system clock works best.[/quote]
ULA's clock range), I'm ... megahertz - 6 times normal clock![/B]... Especially the [B ...You know how the 128K was faster than the 48K Spectrum?Regarding how the Spectrum 128K ran at 3.54 MHz rather than the 48K's 3.5MHz, was this difference enough to be an advantage? If not, then surely Sinc…
... not know the 128 divide ULA's clock down five times... As ...You know how the 128K was faster than the 48K Spectrum?Regarding how the Spectrum 128K ran at 3.54 MHz rather than the 48K's 3.5MHz, was this difference enough to be an advantage? If not, then surely Sinc…
... sounds a bit out of ULA's clock range), I'm drooling ... furious megahertz - 6 times normal clock![/B]... Especially the [B]CIRCLE ... could have divided the standard clock by 2 or 3 instead ...DMA interface for ZX Spectrum[url]http://velesoft.speccy.cz/data-gear.htm[/url] This is internal DATA-GEAR interface for any 8-bit computer with Z80CPU. Use Direct Memory Access…
... will DMA chip know when ULA acesses lower 16K ?[/QUOTE]< ... access to contended memory, ULA stopped clock for CPU.
DMA ... clock is same as for CPU ... 128+2A/+3
ula generate WAIT for CPU. DMA ... work on any ULA model. You
can ...DMA interface for ZX Spectrum[url]http://velesoft.speccy.cz/data-gear.htm[/url] This is internal DATA-GEAR interface for any 8-bit computer with Z80CPU. Use Direct Memory Access…
... DMA access to contended memory, ULA stopped clock for CPU.
DMA ... clock is same as for CPU, ... ZX 128+2A/+3
ula generate WAIT for CPU. DMA ... work on any ULA model. You
can change ...sinclair zx spectrum issue 6a (again) - how to repairHi All, Is there someone who may explain what these jumpers can be used for. [url]http://forest.no-ip.org/repair/jumpers.gif[/url] <- this is from …
... />
the -6 and -7 ULA variants are almost the same ... coupling from the ULA's clock output to the CPU clock input. TR4 ... links for connecting the ULA to CPU clock directly (LK1), Analogue ... supply to ULA direct to +5V ( ...Real 60Hz NTSC 48K ZX SpectrumNot a 3rd party mod. The joystick mod was added by the user, but the board and the computer is exactly what was sold in Chile, South America. We migh…
... technical manual states that the master clock in that machine is 14 ... .112MHz, while the clock we can see in the ... I've seen conceals the master crystal and I'm not ... a result the TS2068 CPU clock is theoretically 3.528MHz (confirmed ...Spectrum +2 datacorderHi, my Spectrum +2 datacorder isn't working. Does anyone know if I can still load software through the tape/sound socket at the back of the machine i…
... this could work because the ULA also reads out the RAM ... in case the CPU had clock the computer would work.Would ... /> Have you see if your ULA gives clock for TEA2000? It's ... the ping 44.
About ULA ...
