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DivMMC clock bufferI have completed the first DivMMC EnJOY today: [url]http://www.worldofspectrum.org/forums/showthread.php?t=44238[/url] But there is a problem with t…
... the weakness of the clock signal (and also its unusual ... that's used for the Z80). I wouldn't usually ... will need a good clock signal). The Schmitt-trigger buffer ... to buffer the reset signal which is very slow ... quite happily prevent the Z80 from ever coming out ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... a first non-trivial Z80 program. The worst thing ... but nevertheless improve my Z80-fu in the process ... amount of work, my Z80 skills are still poor.
.exit_edge_loop:
scf ; signal BREAK not pressed
ret ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... in real life if the signal is marginal, not sure as ... I've been away from z80 :smile:)
Cheers ... -
Corrupt paper on zx spectrum 48kHi. When I power up my spectrum (issue 3) I get the light grey border, but the paper is black and it switches between thin red vertical lines and thi…
... to make sense of the signal(s) displayed on your 'scope ... to know what instructions the Z80 CPU is processing. This is ... the system is faulty, the Z80 may be processing random instructions ... -
Hardware description - MULTIFACE 128I make schematic of MULTIFACE 128 (v36) from PCB layers downloaded from WOS. But all PCB layers on WOS contain some bugs, absent signals, etc.. Now …
... . Press button always active NMI signal to ZX, and detect if ... ] - enable MAGIC button + deactive NMI signal(from MF128 to ZX) + disable ... ] - enable MAGIC button + deactive NMI signal(from MF128 to ZX) + disable ... ,RD/RW and ADDRESS lines, M1 is unused. -
ZX Spectrum clock signals comparedI haven't searched for this on WoS; it might have been posted before. But I think it's important info, and can't do any harm to repeat or show from a…
... is interesting:
"This clock signal is inverted by a transistor ... clean clock edge for the Z80."
This is done ... -
ZX Spectrum clock signals comparedI haven't searched for this on WoS; it might have been posted before. But I think it's important info, and can't do any harm to repeat or show from a…
... is interesting:
"This clock signal is inverted by a transistor ... clean clock edge for the Z80."
This is done ... -
ZX Spectrum clock signals comparedI haven't searched for this on WoS; it might have been posted before. But I think it's important info, and can't do any harm to repeat or show from a…
... speed using outi and ini z80 instructions.
about the contention ... you need the Spectrum clock signal? Wouldn't be a more ... softcore to regenerate the clock signal from the original because he ... -
ZX Spectrum clock signals comparedI haven't searched for this on WoS; it might have been posted before. But I think it's important info, and can't do any harm to repeat or show from a…
... speed using outi and ini z80 instructions.
about the contention ... trick: when synchronising to the Z80 clock, you avoid missing bits ... high currents on the clock signal from the ULA.
With ... pulled tops from the clock signal from the ULA.
With ... -
ZX Spectrum clock signals comparedI haven't searched for this on WoS; it might have been posted before. But I think it's important info, and can't do any harm to repeat or show from a…
... must be synced to the Z80 clock
- it probably ... also be halted when the Z80 clock is halted, to avoid ... pullup on the ZX clock signal higher with only a ... make a decent inverted clock signal out of any ULA clock ... signal, but only when ther ... -
ZX Spectrum clock signals comparedI haven't searched for this on WoS; it might have been posted before. But I think it's important info, and can't do any harm to repeat or show from a…
... toastrack to create a better signal that feeds the 74LVC1G14.
This isolates the Z80 clock from the clock on ... -
RF Modulator, not Astec UM1233While repairing a +2A board (D4 burnt out, so the WAIT signal from the gate array didn't reach the CPU and hence, the CPU was running full speed even…
... , and notice that the WAT signal is side by side with ... ?[/QUOTE]
Or the Z80! -
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…
... configuration FPGA and Z80 firmware.
[*]AD724, generates Composite signal.
[/LIST ... -
Upper RAM replacement module issues with the DivideI got my new upper ram replacement module from Zorn yesterday and seem to be having some issues. When the machine is without the Divide it boots up …
... base current for T3. The Z80 was not designed for that ... bet it is the /MREQ signal causing the problem. -
SE BasicAfter 13 years of development I thought I'd run out of things to optimize, but it turns out I was wrong. However, I'm now running out of time to work…
... text printing.
[*]Fast pilot signal sync.
[*]Fast reset.
[*]Z80 LDIR block copy: PUT 49152 ... -
Quick fix for four joysticksHere's a quick modification to add four joysticks to any Speccy. This assumes you already have two Sinclair ports. [URL="http://joefish.co.uk/specc…
... that is wired in is 'M1!' - I can't find any ... ZX bus, then not need signal M1. You can use any other ... instead A5 and A5 instead M1 then new joystick port address ... -
Quick fix for four joysticksHere's a quick modification to add four joysticks to any Speccy. This assumes you already have two Sinclair ports. [URL="http://joefish.co.uk/specc…
... ZX bus, then not need signal M1. You can use any other ... instead A5 and A5 instead M1 then new joystick port address ... line and connect it to M1, does that mean it would ... -
+3 with dead expansion portI bought a +3 from a WoS user. So far, the computer works as expected, but when an interface (e.g. DivIDE (configured correctly) or Multiface3) is co…
Both interfaces use M1. Maybe your Z80 is defective. -
+3 with dead expansion portI bought a +3 from a WoS user. So far, the computer works as expected, but when an interface (e.g. DivIDE (configured correctly) or Multiface3) is co…
... classic case of a Z80 with a faulty M1 line. Had a ... -
+3 with dead expansion portI bought a +3 from a WoS user. So far, the computer works as expected, but when an interface (e.g. DivIDE (configured correctly) or Multiface3) is co…
... pretty sure that all the z80 processors in the ZX Spectrum ... that exchanging the z80 on your +3 fixed the M1 fault but ... -
Spectrum CP/MHello.. Just out of curiosity, has anyone actually used +3 CP/M for any practical purpose? I remember booting it up a couple of times years ago, jus…
... optimize signal paths for speed. At that time, the z80 processor could ... speed because of the extra signal path length presented by these ... -
Toasted +3Oops.. I shorted one of my +3 (being clumsy with multimeter, doh) when measuring PSU connector pins :D Any immediate guesses what exactly died on thi…
... minus 12v connections to the Z80 with a probe there. I ... killed a Z80 this way. If you shorted the !M1 line to ... -
Toasted +3Oops.. I shorted one of my +3 (being clumsy with multimeter, doh) when measuring PSU connector pins :D Any immediate guesses what exactly died on thi…
... minus 12v connections to the Z80 with a probe there. I ... killed a Z80 this way. If you shorted the !M1 line to ... -
Toasted +3Oops.. I shorted one of my +3 (being clumsy with multimeter, doh) when measuring PSU connector pins :D Any immediate guesses what exactly died on thi…
... the TV is detecting a signal then (blue is presumably the ... "no signal" state)
If you ... screen.
Possibly the Z80 CPU? I noticed pin 26 ... on the z80 (reset) goes to IC15 pin ... -
Toasted +3Oops.. I shorted one of my +3 (being clumsy with multimeter, doh) when measuring PSU connector pins :D Any immediate guesses what exactly died on thi…
... seems to be detecting a signal) then it at least the ... video ram reads, is the Z80 getting a clock etc etc) -
Toasted +3Oops.. I shorted one of my +3 (being clumsy with multimeter, doh) when measuring PSU connector pins :D Any immediate guesses what exactly died on thi…
... measure stuff like the CLK signal making it to the ASIC ... /> Same goes for stuff like /M1, /MREQ, /RD, /WR etc - if ... -
Toasted +3Oops.. I shorted one of my +3 (being clumsy with multimeter, doh) when measuring PSU connector pins :D Any immediate guesses what exactly died on thi…
... /> Video through RGB gives some signal (monitor detects it). All borders ... does not like an input signal on the tape output line ... do-able.
The Z80 CPU is probably on a ... -
Toasted +3Oops.. I shorted one of my +3 (being clumsy with multimeter, doh) when measuring PSU connector pins :D Any immediate guesses what exactly died on thi…
... when he swops out the Z80.[/QUOTE]
The last pin ... IC15 that inverts the reset signal and its via is very ... -
Toasted +3Oops.. I shorted one of my +3 (being clumsy with multimeter, doh) when measuring PSU connector pins :D Any immediate guesses what exactly died on thi…
... also reaching the ASIC and Z80. For example, if the over ... is effectively preventing the reset signal from ever rising, holding the ... -
New CPU and Spectranet oddity.I have no reason to suspect this problem is due to a fault/poor design of the Spectranet, but understanding what it does at system initialisation may…
... Spectrum+ 48K. Replacing the Z80 CMOS CPU to the original ... no problems. With the Z80 CMOS CPU the situation was ... to look at the clock signal. (I don't have ... the clock signal at the CLK pin of the Z80 CPU ... with the different CPU types. The clock signal ...
