-
ZX Spectrum+ adviceHey all, I just got a ZX Spectrum+ from eBay and I'm not sure yet what to do with it. I wanted to first take a peek inside, see what issue board it i…
... test for a composite video signal is an oscilloscope.
signal. Then you should get a ... the speaker. If yes, the Z80 CPU is running BASIC. Note ... -
Grey +2 - DOA and no power lightTook a punt on a grey +2 at the weekend to be a spare. It was "untested" although so were all my other +2's which are all fine. Tried to power th…
... getting hot either but the Z80 was.
Replaced voltage ... the TV there is a signal on the SCART so the ... no signal message goes away but nothing ... -
External Z80 CPUHi Looking for some advice if possible. Many years ago I had a plug-in board for a Spectrum 48k which had a couple of switches, a z80 CPU, and a S…
... . So to disable the internal Z80 CPU, connect /BUSREQ on the ... to provide a decoded select signal for the external EPROM. The ... -
Access to ZX81-Service ManualI need the ZX81-Service manual to repair my sick Zeddy. Unfortunately I don't get access to WOS documents via ftp. How can I register? For the ZX-S…
... pins rewiring.
The Z80 CPU is fairly reliable, but ... porch" part of the video signal. The last ULA version, the ... -
IN and OUT in hardware terms... what are 'ports'?Hi all, I understand PEEK and POKE, but have never managed to get my head around IN and OUT. The books all go on about how they read from and wri…
... , really, apart from one hardware signal. In fact, if you really ... 64K of memory to the Z80 and access it via IN ... -
Opus Discovery "the big switch on" (after 20 years)I have a few of these Opus Discovery's with different Eproms in that have not been swiched for 15-20 years or so . I am in no rush to switch any on …
... working 100%:if the M1 line of the Z80 CPU is not ... -
Opus Discovery "the big switch on" (after 20 years)I have a few of these Opus Discovery's with different Eproms in that have not been swiched for 15-20 years or so . I am in no rush to switch any on …
... gives out NMI pulses towards Z80.
(So the disk read ... via address 102...)
This signal line 'enters' Opus but is ... -
Why were there no SN76489-based sound interfaces for the Speccy?I’ve been wondering for a while now why there were no SN76489-based sound interfaces for the Spectrum. Does anyone here have an explanation? There…
... simply by connecting its ready signal ORed with chip enable (cpu ... the same as the 4MHz z80 clock, you would probably have ... collector ready signal from the SN chip directly to the z80's ... -
A few hardware questions regarding Z80 and eZ80Hi Guys, Maybe some of you could help me with these questions: I would like to know what is the actual file size limit that can be used by z80 …
... 100% compatible with legacy Z80 code. I don't ... based off the classic "Z80" core should be compatible ... with legacy Z80's. But, I ... n-whistles along with a "Z80 type" core. I mean, ... loose the colorburst reference signal so that you can ... -
A few hardware questions regarding Z80 and eZ80Hi Guys, Maybe some of you could help me with these questions: I would like to know what is the actual file size limit that can be used by z80 …
... implement the hardware supporting the Z80 CPU. Bank switching is not ... an image processed by the Z80 CPU. However the more pixels ... . The Z80 depends on support chips to generate a video signal and ... -
Vega ARM SOC?I read that the core of the new Vega was an ARM SOC. I thought it would have been an FPGA. But it seems it's an ARM running an emulator. Anyone kn…
... that ARM is doing the Z80 / ULA emulation along with creating ... to help generate a video signal. Say, a framebuffer for example ... -
Faulty 48+ Help NeededHi, This is what I get when I plug in the spectrum, this is tuned in. Vid shows a reset. Any ideas, or pointers on the first thing to check. Keyboa…
... something wrong there. Either the Z80 is somewhat dead or something ... as if it manages to signal the ULA to set the ... -
Were there other graphic modes for the ZX Spectrum?I've read that there was a "hi-color" mode that allowed the color clash to be 8x1 instead of 8x8. Maybe I have the name of that mode wrong. I'm…
... was build up by the Z80 CPU doing half the work ... allowed to build the video signal, (as in FAST mode) you ... is not a lot the Z80 CPU can do to change ... -
7mhz CPU?One of the things I like about Spectaculator, is that I can zap the clock speed of the emulated CPU up. Doing so makes me wonder about why the desig…
... input a clock signal straight in to the Z80 from a separate ... -
7mhz CPU?One of the things I like about Spectaculator, is that I can zap the clock speed of the emulated CPU up. Doing so makes me wonder about why the desig…
... ULA that provide a clock signal to the CPU would have ... a problem, as a 7MHz signal already exists). But all the ... could switch the clock signal to the Z80 CPU, stopped the clock ... the CPU clock signal (in fact, ALL the signal timing), it does ... -
NTSC Compatibility?Correct me if I'm wrong, but wasn't the Timex 2068 the only NTSC clone built of the ZX Spectrum? And I use clone lightly... From what I underst…
... (8x1 attribute clash) then the Z80 would need to wait for ... ? IIRC, the only way the Z80 (or any software) could possibly ... the ULA fires an interrupt signal once per frame. Right? How ... -
Opus Discovery "the big switch on" (after 20 years)I have a few of these Opus Discovery's with different Eproms in that have not been swiched for 15-20 years or so . I am in no rush to switch any on …
... by means of the 'MotorOn' Signal. And there usually are no ... and HD disks. (Opus and Z80 only do DoubleDensity!)
Matron ... -
Opus Discovery "the big switch on" (after 20 years)I have a few of these Opus Discovery's with different Eproms in that have not been swiched for 15-20 years or so . I am in no rush to switch any on …
... A14 holding NMI, and this signal is indeed not brought out ... is used for synchronisation between Z80 and Floppy controller. That is ... -
Dead issue 3b with black and white barsHi all, I've been donated an issue 3b which has some nice black and white bars with a few flashing blocks. I've done a few RAM tests and could spo…
... the Z80 CPU is dead, the CPU has no clock signal from ... you have a good clock signal on the CPU (pin 6 ... ). All these are on the Z80 CPU pins.
If ... -
Dead issue 3b with black and white barsHi all, I've been donated an issue 3b which has some nice black and white bars with a few flashing blocks. I've done a few RAM tests and could spo…
... the Z80 CPU is dead, the CPU has no clock signal from ... the RAM chips or the Z80 dying, what's going on ... -
Internet enabling a SpectrumHi, Yonks ago, I floated the idea of using one of these: http://www.mycal.net/old/wsweb/img/s7600a.pdf ..to Internet enable a Spectrum. I d…
... design and storing the base Z80 code (network and filesystem driver ... RAM on boot so the Z80 could execute it, and storing ... the requirement for the CLK signal and making it vertical (with ... -
Faulty M1 or no?Hi all, OK, so I've got an issue 4B which was pretty much untouched and appears to work fine (starts up OK, loads games, 23732 and 23733 both retu…
... ! a dodgy M1 line", so I removed the Z80, fitted a socket ... and inserted another (known working) Z80, still the same. I also ... put the Z80 from the 4B into another ... -
Faulty M1 or no?Hi all, OK, so I've got an issue 4B which was pretty much untouched and appears to work fine (starts up OK, loads games, 23732 and 23733 both retu…
... be checked for continuity between Z80 pins and edge connector contacts ... all address lines, NMI, RD, M1, MREQ and ROMCS. -
ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... have a Write (WR) signal, which IF2 socket does ... is a way to signal cartridge inputs, like: ... D7-D0) , and MemReQuest signal, since these are the only ... is to detect the Z80 instruction address and data ... reset.
Z80 is constantly outputting I and ... -
ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... all the accesses by the z80 running the program aaaaargh. Gate ... that there's no reset signal at the cartridge socket, so ... -
ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... behaviour.
From Z80 Manual
[quote]Memory Refresh ... along with a refresh control signal while the CPU is ... .
NOTE: All Z80 repeat instructions, like LDIR, LDDR ... increment correct, due to some Z80 quirk ?
Or
... -
R registerI'm cross-posting this as a spin-off of a [url="http://www.worldofspectrum.org/forums/discussion/52748/zx-spectrum-cartridges/p2"]thread in "Hardware…
... instructions have more then one M1 cycle.
So, went ... , and found a chapter in "Z80 documented V0,91"
M1 two[/b]), the memory refresh ... . It is unclear whether the Z80 increases the R register before ... -
ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... I found the following in "Z80 documented V0.91":
M1 two[/b]), the memory refresh ... -
SMART card not workingHi all, I've got an issue 3 48k which appears to be working fine apart from with a Retroleum SMART card. The card (which works fine on my other Sp…
... each edge-connector signal has continuity to the relevant Z80 CPU pin ... -
ZX Dandanator! Mini - Cartridge system for SpectrumsHi All, I'd like to present a little HW I've developed during the last three months. It's aimed at providing a console-like usage experience for a…
... requires 8 GPIOs + 1 WR signal. If you see the schematic ... -cost.
Also, a Spectrum Z80 takes around 400ns from signaling ...
