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DivMMC and K-Mouse Turbo incompatibilityToday I tested a setup someone wants to use, but of which he can't get the K-Mouse Turbo working. The setup contains of: - ZX Spectrum 128K (toastra…
... if detect IORQ=0 and M1=0. But if CPU use ... too low logic level of M1 line.
You can ... M1 line from zx bus and connect to k-mouse signal +5V ... instead M1. Now will kmouse not ... I mean - bad quality of M1 logic level. You can swap ... -
Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
... from the ULA. So what signal do you get on this ... .
So, is the Z80 socketed?
... If yes, have ... -
Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
The Z80 is not executing the correct ... one will have a bad signal (the one that had +5V ... -
Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
[QUOTE=1024MAK;765141]The Z80 is not executing the correct ... one will have a bad signal (the one that had +5V ... 20 Mhz version of the Z80 work at the lower clock ... -
How much would you pay for this FPGA clone?...given that a mint 128 goes for around ?125. [img]https://dl.dropboxusercontent.com/u/15659782/chloe280seboxed.jpg[/img] Features: [list] [*]100%…
... of outputting an NTSC composite signal. Again, this would require a ... ?[/quote]
Given that the Z80 is on the FPGA it ... -
Yellow issue 4A keyboard madnessNote sure if this is a similar problem to the one CornishManicMiner has, but one of my yellow issue 4A boards is driving me crazy. I had it in variou…
... many expansion devices use this signal, but you may want to ... (ULA) pin 33 and IC2 (Z80 CPU) pin 11 (+5V) and ... -
DivMMC and K-Mouse Turbo incompatibilityToday I tested a setup someone wants to use, but of which he can't get the K-Mouse Turbo working. The setup contains of: - ZX Spectrum 128K (toastra…
... keyboard interface) with the CPLD-M1 connected to 5V.
Unfortuntately ... solved completely by replacing the Z80 CPU.
Let's test ... -
How much would you pay for this FPGA clone?...given that a mint 128 goes for around ?125. [img]https://dl.dropboxusercontent.com/u/15659782/chloe280seboxed.jpg[/img] Features: [list] [*]100%…
... jumper you'll have PAL signal. Same for NTSC. So it ... to rewrite from scratch the Z80 core (is the T80 from ... -
Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
... etc.) somewhere between the INT signal and one of the outputs ... .
So IMHO the INT signal should be checked with and ... LS32, and best at both Z80 and ULA pins.
For ... -
Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
... etc.) somewhere between the INT signal and one of the outputs ... .
So IMHO the INT signal should be checked with and ... LS32, and best at both Z80 and ULA pins.
For ... changed.:confused:
INT Signal shows 5V with slow pulse ... -
Issue 4S differencesI decided to buy an Issue 4S PCB after reading much about them on here. It was originally in a plus case which didn't come in the sale. I've been run…
... with bad M1 lines (and it's always a faulty Z80). And ... with a bad M1 line but a NEC Z80. Perhaps a line ... -
Issue 4S bad M1Never ever seen a 4S with a bad M1 line before today [url=http://postimg.org/image/o2yrigdb1/][img]http://s14.postimg.org/o2yrigdb1/IMG_1291.jpg[/img…
... 48K with Zilog Z80 of which the M1 line died when ... br />
So the M1 line 'died in his hands ... or something which killed the M1 lines on all toastrack ... intensive use of the M1 line from Z80 CPU's from ... Maybe we should buffer the M1 on new interfaces in the ... -
Issue 4S bad M1Never ever seen a 4S with a bad M1 line before today [url=http://postimg.org/image/o2yrigdb1/][img]http://s14.postimg.org/o2yrigdb1/IMG_1291.jpg[/img…
... the same problem with M1. The Z80 looks almost identical to ... not new problems with M1, they've probably been ... the Divide design uses M1, and nothing on the ... board itself. So the M1 line isn't heavily ... previously machines with faulty M1 lines would have been ... -
Issue 4S bad M1Never ever seen a 4S with a bad M1 line before today [url=http://postimg.org/image/o2yrigdb1/][img]http://s14.postimg.org/o2yrigdb1/IMG_1291.jpg[/img…
... that the various manufacturers of Z80 CPUs would have sold them ... with defective /M1 outputs.
[/QUOTE]
M1 is right next to a ... ones with Z80s with bad M1 lines (hence my speculation elsewhere ... -
48K: Half of copyright message in the middle of the screen?!Issue two. Has 74LS08 over the Z80, but the ULA is 5C112E-3 (I think this should be a 5C102E??? - I have one, but I'm not sure if it is working, at l…
... "upper" RAM, as the CAS signal won't reach the RAM ... chips, and most likely the Z80 CPU will be one that ... a pin-out of the Z80 CPU.
[IMG]https://farm8 ... -
New user with a dead 48k issue 2Hello all I've found my way here from watching some excellent youtube videos by Joulesper Coulomb in an attempt to fix a issue 2 rubber key 48k I bo…
... a pin-out of the Z80 CPU.
[IMG]https://farm8 ... the following pins of the Z80 CPU
16 /INT ...
26 /RESET
27 /M1
28 /RFSH
DivMMC and K-Mouse Turbo incompatibilityToday I tested a setup someone wants to use, but of which he can't get the K-Mouse Turbo working. The setup contains of: - ZX Spectrum 128K (toastra…
... />
I have checked the M1 line with the two interfaces ... . It was interesting, that the signal low level was -480mV, the ...48K: Half of copyright message in the middle of the screen?!Issue two. Has 74LS08 over the Z80, but the ULA is 5C112E-3 (I think this should be a 5C102E??? - I have one, but I'm not sure if it is working, at l…
... "upper" RAM, as the CAS signal won't reach the RAM ... chips, and most likely the Z80 CPU will be one that ...ZX Spectrum Clock Signal Restorer Circuit[SIZE=5][U][B]ZX Spectrum Clock Signal Restorer Circuit[/B][/U][/SIZE] The circuit below is an experimental circuit. It has only been "tested" using…
... between the ULA and the Z80 CPU.
... Green = simulated poor input clock signal
Dark blue = schmitt ... Red = Q1 base signal
Cyan = Q1 collector signal (input to schmitt ... inverter)
Magenta = Q1 emitter signal
[I][B ...Spectrum+ keyboard issueHi I have a spectrum+ (issue 4s board) where the 1-5 keys do not work. I have replaced the membrane and checked for continuity. I have also tested …
... the "top" Z80 address lines A8 to A15 via signal diodes.
Z80 CPU?
Oh, and ...48K: Half of copyright message in the middle of the screen?!Issue two. Has 74LS08 over the Z80, but the ULA is 5C112E-3 (I think this should be a 5C102E??? - I have one, but I'm not sure if it is working, at l…
... needs the 74LS00 over the Z80, is working as well, or ... that the modulator transmits a signal. Surprisingly, the power circuits are ...ZX Spectrum Clock Signal Restorer Circuit[SIZE=5][U][B]ZX Spectrum Clock Signal Restorer Circuit[/B][/U][/SIZE] The circuit below is an experimental circuit. It has only been "tested" using…
... to make an acceptable clock signal for the DivMMC EnJOY! and ... to use inverters for clock signal "amplification". Originally he recommended ... DC offset on the CK signal at the edge connector. Without ... Spectranet. I've replaced the Z80 and it fixed the operation ...Issues with 48k spectrum and divIDEI heard you can have all kinds of issues with 48k spectrum and certain DivIDE models. Is this true and if so what should I look out for ? Only aski…
... is a bad /M1 line on the Z80 that wasn't picked ... /> Fix is to replace the Z80. The overwhelming majority of machines ...Issues with 48k spectrum and divIDEI heard you can have all kinds of issues with 48k spectrum and certain DivIDE models. Is this true and if so what should I look out for ? Only aski…
... up having a Z80 CPU that has a malfunctioning /M1 output. However ... so a Z80 CPU that has a damaged /M1 output will ... report problems about finding Z80 CPUs with malfunctioning /M1 output (there are ... may have a Z80 CPU with a malfunctioning /M1 output. So far ...Issues with 48k spectrum and divIDEI heard you can have all kinds of issues with 48k spectrum and certain DivIDE models. Is this true and if so what should I look out for ? Only aski…
Well if my issue 2 had a faulty m1 line I have here a NEC D780C Z80 which is fully working.
Would this work in a 48k as I bought it for a +2 ?MISSING M1 LINE ON +48????I was posting questions about my DIVMMC enjoy not working on one of my +48`s and have now got round to testing if its cpu related.Trouble is the one …
... a little about the faulty m1 line and i think i ... absence of the /M1, or the quality of the clock signal :DRTC module for DIVIDE[IMG]http://velesoft.speccy.cz/other/rtc_module_v01_full_top.jpg[/IMG] [IMG]http://velesoft.speccy.cz/other/rtc_module_v01_full_bottom.jpg[/IMG] [IMG…
... (A7-A0=BIN 00011111) and M1 line is ignored.
[B ... reding of ports #000111xx reset signal "SELECT" on joypad connector
signal "SELECT" on joypad connector
Question for ZX81 GurusI have an ISSUE 1 ZX81 with a 2C184E ULA. If I ever need to change it, can I use one of the newer 2C210E ULAs? If I can, are there any other mods th…
... Issue 1 board gives a signal (BLACK) and the TV stops ... - I've already changed the Z80. Using a 210 ULA replaces ...Spectrum Issue 2 - TR6 ReplacementI've just got my hands on an Issue 2 ZX Spectrum, that needed some repairs. The picture quality after doing a composite modification was pretty shodd…
... transistor on top of the Z80 is known as "the spider ... be replaced with any small signal NPN transistor. So a BC547 ... go on top of the Z80. Some Spectrum boards have TR6 ...Issue 3 expansion connector problemI am having problems with an issue 3 Spectrum, that otherwise works fine, but does not recognize either the Interface 1 or DivMMC/Enjoy (which are bo…
[QUOTE=Tuukka;789843]some signal is missing from the connector, but what?
Tuukka[/QUOTE]
Bad /M1
