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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…
... switches, a z80 CPU, and a Spectrum ROM on it (maybe ... the switches (wwhile the power was off), could force ... ROM and/or CPU instead of the on-board ones. I ... 't recall how the Z80 was switched. The ROM ... really having problems with the CPU. Can anyone advice if ... -
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…
... the CLK leg on the motorola 68000 cpu (which in the ... lot of moving sprites were on the screen. There was ... believe was handled by a Z80 cpu).
Well, I ... +3e) by lifting the Z80's CLK pin and adding ... Wondering what your thoughts are on this and if it's ... -
Using a Z80 CPU in a 48K Spectrum?Will a Z80 CPU (which I have) work well enough in a 48K Spectrum to give me an indication as to whether the Z80A CPU in there is duff? Thanks for re…
Will a Z80 CPU (which I have) work well enough in a 48K Spectrum to give me an indication as to whether the Z80A CPU in there is duff?
Thanks for reading - weathereye. -
Which type of Z80 cpu to use with ZX 48?Which type of Z80 cpu can I use with ZX 48? Only the 4 MHz cpu's or some with more MHz? Did not know if a 6 MHz cpu runs in a ZX 48 with 4 MHz. Mic…
Which type of Z80 cpu can I use with ZX 48? Only the 4 MHz cpu's or some with more MHz? Did not know if a 6 MHz cpu runs in a ZX 48 with 4 MHz.
Micky -
Spectrum 48k Power On ProcessI have a 48k Spectrum here that maybe does something strange on power on. Could somebody confirm what is meant to happen when power is applied? On …
... that maybe does something strange on power on.
Could somebody confirm ... to happen when power is applied?
On this one I ... -
what components normally get taken out if you plug+unplug a joystick interface in with the power onwhat components normally get taken out if you plug+unplug a joystick interface in with the power on? i remember doing this a few times when i had …
... joystick interface in with the power on?
i remember doing ... -
Of course, when the M1 line of the Z80 CPU is failing, the Z80 CPU must be replaced![quote]Of course, when the M1 line of the Z80 CPU is failing, the Z80 CPU must be replaced![/quote] Err, why? If you are trying to use an interfa…
... M1 line of the Z80 CPU is failing, the Z80 CPU must be replaced ... or expansion that needs a Z80 MPU with a working /M1 ... -
likely damage caused to +2 by too highly rated supplyHi. did have a quick search but couldn't see an answer. I've been offered a +2 which the previous owner damaged by connecting too high a power supply…
... you have a spare Z80 CPU to exchange on the +2 motherboard?
Just exchange the CPU and power up the motherboard, see 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…
... wires soldered in to feed power to disk drive etc). No ... .
Holding break key during power on gives no visible or audible ... not like an input signal on the tape output line. This ... -able.
The Z80 CPU is probably on a socket - try a ... -
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…
... disable the internal Z80 CPU, connect /BUSREQ on the edge connector ... condition).
On the external CPU, use a pull-up ... , /NMI, and /HALT on the external CPU to the edge connector ... use the switch to select. Power down before switching ;-)
... -
SimCoupe 1.0 released[size=-2](for those of you that don't read CSS)[/size] SimCoupe, the SAM Coup? emulator, has been updated to version 1.0. This major release adds ma…
... during first ~49ms after power-on
- Added support ... /> - Fixed digit input on Czech keyboards, which require ... - Fixed disk image saving on Windows shutdown/restart [Win32]< ... Improved RAM, paging, CLUT and CPU register power-on states
- Improved DAC ... -
SPECTRA New from Paul FarrowLooks good! Read about it [URL="http://www.fruitcake.plus.com/Sinclair/Spectrum/Spectra/SpectraInterface.htm"]here[/URL]
... lower (read "video") RAM. Depending on the mode, the attributes area ... 674206]could either of the z80's in these interfaces access ... t have its own Z80 CPU. All logic on the SPECTRA is controlled ... help provide a data base on which hardware interfaces are ... -
Diagnostic Board (Winston designed) PCB'sHi everyone, I had these made earlier in the year, built mine then promptly mislaid the others until now :) and I'd like to offer these to the commu…
... put diagnostic board and power on speccy, nothing happened? ... way, I removed cpu put socket and place ... new working cpu - result is same, ... removed cpu and power on speccy and led lights on diagnostic board ... don't have working cpu or what? what ... -
ZX Spectrum +3 repairI have my first +3 here, and it needs repairs. Hoping someone here can help me out. When I power it on I get this screen with black and white line…
General for all 8 bit CPU systems:-
If the address ... getting to the CPU?
Is the CPU being held ... in reset?
Does the CPU have power on ... it's power pins?
[ ... -
How feasible is it to add a second CPU to the ZX Spectrum?Today with IDE, and USB, and TCP/IP and other wonderful technologies arriving on the ZX Spectrum, I'm beginning to wonder if we'll run out of CPU tim…
... of CPU time, for handling all of these devices on the weak Z80 ... maybe a third and fourth?) Z80 shared our contended memory, then ... software perspective) expand the computational power of the ZX Spectrum. Let ... able to write into the CPU registers AF, BC, DE, IX ... -
IDE Hard Drive on your Spectrum!Hello there my fellow WoS'ers Today, I am going to share with you something that has truly captivated me over the last couple of months, some of you…
... carefull - So from the schematics on the interwebs I redesigned the ... device, this plugs into the Z80 CPU socket and provides an IDE ... the community and knowledge thats on offer!
Now, ... see there are some standard power molex's comming from the ... -
ESXDOS 0.8.5 and .Z80 on +2B or +3Last week I received some .Z80 snapshot files from a DivMMC EnJOY! user to test. These files didn't work on his ZX Spectrum +2B. [URL="http://benophe…
... These files didn't work on his ZX Spectrum +2B.< ... /> I tested the files on a toastrack, and they ... a situation where the Z80 CPU was a cause of ...
Imre tried the files on an emulator with DivIDE support ... create a bug report on [URL="http://board.esxdos ... -
Restoring AY registersAfter doing (not still finished) the sna to tap converter, I'm going to try to do the same for 128k snapshots. I've got threee ideas about what to do…
... ve only found them in Z80 snapshots (I guess SZX ... transfer code to restore CPU registers and execute the program ...
[b]3.- Load AY registers on screen:[/b]
Same as ... and before restoring CPU registers).
AY registers would be "out ... -
How does interrupts work?I am a little confused regarding the interrupts on the Spectrum. If I have some hundred bytes of machine code started with, say, [B]RANDOMIZE USR 300…
... . At power up the Spectrum ROM puts the z80 in IM1 ... routines must preserve all registers used on the stack and restore ... do anything on its own -- at some point the cpu is ... cpu (which I gather is what you meant) depends on ... communicate keypresses to the cpu. -
RAND USR that doesn't work in emulators and clonesEons ago, I "discovered" a strange RANDOMIZE USR. This is it: [b]RANDOMIZE USR 46578[/b] Using it on a genuine ZX Spectrum rubber key or Plus model,…
... , my Z80's put all registers to $FF at power on. What ... say that the CPU reset puts all registers to 0, but ... this also happens when I power on ... reset button while I power on the machine, hold the ... a subset of the registers and doesn't touch ... -
RAND USR that doesn't work in emulators and clonesEons ago, I "discovered" a strange RANDOMIZE USR. This is it: [b]RANDOMIZE USR 46578[/b] Using it on a genuine ZX Spectrum rubber key or Plus model,…
... think that not all registers inside the CPU are modified. The only ... machine stays on) is to assume that at power on, all registers contain $FF ... assumption is that before that initialization is performed, the original value ... -
RAND USR that doesn't work in emulators and clonesEons ago, I "discovered" a strange RANDOMIZE USR. This is it: [b]RANDOMIZE USR 46578[/b] Using it on a genuine ZX Spectrum rubber key or Plus model,…
... reset. At least, not on the CPU I've tested.
- The values of the Z80 registers upon power up are not 00, nor ... other registers are undefined (different depending on how long the
CPU has ... -
+3 - beeper sounds but no AY musicHi guys I am repairing a plus 3 revision 2 board that had no sound at all. Using schematics from https://zxnet.co.uk/spectrum/schematics/ I manage…
... simply turned the power to the built in speaker on or off ... . To get a usable sound out, the Z80 CPU ... had to turn the speaker on and off fast ... the Z80 CPU has to do is set the internal registers in the ... -
Spectrum +3 fault - flashing screen on power onHi ive just bought a +3 When I power it on the power led and disk drive led come on. The screen just flashes black and white around the border, almos…
... +3
When I power it on the power led and
disk ... drive led come on.
The ... -
NEW INTERFACE FOR ZX SPECTRUM!!Hi all zx-maniax! Here is a letter from Polish inventor, Yarek Adamski. He constructed a new brilliant interface for ZX SPECTRUM. Ready carrefuly i…
... them.
(Of course while power off!)
I ... /> wide range of computers based on Z80 CPU - e.g. ZX
... with computers
of other CPU (6502, 68000), but this is ... /> Additional informations you can find on:
[url="http://zx.yarek ... -
Spectrum 128k+ for saleHi, I have an excellent condition Spectrum 128k+ (heatsink type) that has been totally reconditioned. -New capacitors, AY sound chip, Z80 cpu, membra…
... /> -New capacitors, AY sound chip, Z80 cpu, membrane, etc...
works great ... the computer ([B]no[/B] power supply or cables or orig ... Message was edited by: thomas3120 on 2004-05-18 20:37 ] -
ZX Spectrum 128+ problemsHello!I recently purchased and got myself a spectrum 128+ from ebay.The item did not have an original power supply so i got a power supply of 9volts …
... not have an original power supply so i got ... the RF cable on channel 36.On the same ... 128+ is connected on that channel the tv ... Made-of-ULA-Chip-for-Z80-CPU-ZX-Spectrum_W0QQitemZ120137893224QQihZ002QQcategoryZ4193QQrdZ1QQssPageNameZWD1VQQcmdZViewItem[/url]
Z80 Expander Bus ControllHello there my fellow forum chummies, I would like to ask a few technical questions, Now I come from an Amiga Hardware based background, and as yo…
... any links to some decent Z80 expansion port schematics?
< ... Building a passive 2 port Z80 inteface expander[/b]
... Interface for direct install on the Z80 cpu
Will this ... interfere with the Z80 expansion Bus
...48K Speccy Repair Log.Some people may know my love for writing up my repairs of arcade PCBs on various forums so thought I would do the same for this little fella. Had th…
... a chip level, the Z80 CPU only has 16 address ... they require 3 separate power supplies, each chip needs ... slot, all these power rails are present on the rear slot ... a test tool, the CPU on the board is hogtied ... socket was providing the correct power, it was, and ...IM2 calls to player routine on 128k?Hi all, Apologies for being crap, and not even in a funky, skillo kind of way but it's been over 20 years since I last wrote anything in machine cod…
... for the spectrum, and indeed Z80.
I only ever ... before halt keeps munging my registers around. On the old beeper, ISTR ... anyone here have any pointers on what I can do with ... syncing music to stuff on screen in Z80? I'm afraid I ...
