-
Which ULA?Just a quick question, more of interest rather than immediate need... I am thinking ahead about the repair of an Issue 2 board, and also an Issue 6A …
... a membrane fault :)
No corruption on screen :) which is ... try some resistors between 5V and the molex pins ... for this.[/QUOTE] The Spectrum presumably worked at one ... so this may well make no difference.
... line to 0V, +5V and to any adjacent ... -
Cascading transistorsMiguel (mcleod_ideafix) alerted me on an aspect of a design I'm working on where I am cascading transistors, which may give problems. This is the par…
... to Ve (Spectrum) to insure non-conducting.[/quote]
No quite close ... the capacitor used in the Spectrum (not low, I pressume) but ... signal, which will go from 5V (cut) to 5*100/220100 ... -
PlusDlite prototype/first batch is here![IMG]http://benophetinternet.nl/hobby/vanmezelf/20130605_143221.jpg[/IMG] [IMG]http://benophetinternet.nl/hobby/vanmezelf/20130605_153930.jpg[/IMG] …
... of first batch
2. no stable 8 MHz from clock ... Chinese 5V power supplies cause some distortion at the ZX Spectrum's ... -
Commodore 1702 NTSC to PAL modIs it possible to mod a Commodore 1702 monitor to accept PAL colors? I can get it to sync with the 50hz signal in black & white by adjusting V-Hold. …
... NOT to accidentally plug your Spectrum power supply into it instead ... of the supplied 5v supply, because there will be ... the VGA converter will be no more). -
Commodore 1702 NTSC to PAL modIs it possible to mod a Commodore 1702 monitor to accept PAL colors? I can get it to sync with the 50hz signal in black & white by adjusting V-Hold. …
... NOT to accidentally plug your Spectrum power supply into it instead ... of the supplied 5v supply, because there will be ... the VGA converter will be no more).[/QUOTE]
I ... -
Issue 2 crashes after about 30 minsHi Guys, I have an Issue 2 zx spectrum that seems to get graphic corruption after about half hour of playing, then finally falls over and crashes. …
... ]Next, the rectifier:[/B] With no load, the only current flowing ... ac from the transformer. With no load current to discharge them ... voltage regulator chip inside the Spectrum (just like on a lot ... it stays within 5% of +5V :)
I hope this ... -
ZX spectrum 128K + 2 (Grey one :)Hi all, I'm trying to revive a dead ZX 128K +2 (the grey one). The regulator was damaged and seemed to be feeding 7.8Volts onto the pcb. Yikes ! I…
[U][B]The Spectrum internal inverter power circuit[/B][/ ... to the voltage on the +5V line (which is a well ... to generate the -12V and -5V power rails.
Now ... inexpensive design and there is no overload protection whatsoever.
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…
... DivMMC working on all ZX Spectrum models![/B][/SIZE]
I ... to feed the 74LVC1G14 (had no 330 ohm smd's laying ... from the ZX clock to 5V.
Now everything works perfectly ... 8 mA.
Is that no problem to a ULA?IF1bis StabilityI just thought I would start a different thread relating to the IF1bis, and leave the copyrighters to it elsewhere...:-P I've had mine for a few mon…
... />
1. Spikes on the 5V line at power-up
Spectrum 48k, fitted with fresh capacitors ... [/B].
There is no need to load the operating ...IF1bis StabilityI just thought I would start a different thread relating to the IF1bis, and leave the copyrighters to it elsewhere...:-P I've had mine for a few mon…
... power (under 1V, instead of 5V), despite being fully in order ... of the edge receptacle showing no sign of deformation or damage ... expansion cards), while with the Spectrum, they are actually abused, beyond ...First time capacitor replacementHi, I have an Issue 2 board, that i wish to start with recapping as advised on here, as they look to be all original. (Same with V3 board, but going…
... ...
Normally there is no need to renew ceramic capacitors ... provides the internal +12V and -5V has to work hard. If ... it. Don't run the Spectrum without the heatsink attached.
I see no reason to remove working chips ...Toastrack trouble[IMG]http://i44.tinypic.com/11lq7id.jpg[/IMG] Sorry about the picture size, cant figure out how to make it smaller! Anyway, the pic says it all, th…
... /the-adventure-of-the-128k-spectrum-with-no-display/"]Here's[/URL ... 's only kicking out 4.5v - replace that too.
Video problem on grey +2I have a bad video problem on grey +2. The computer is in a poor shape, but the major problem is with the video. With a (known good) SCART cable I ca…
... and the CSync from the Spectrum on pin 16 (blanking), then ... even be possible that the Spectrum has no problem, it just outputs ... socket and use a 1.5V AA battery to ensure that ...Issue 3 board with strange piggy-back boardIn case you are interested. I?ve never seen something like this before. I have an Issue 3 board here. When I opened the case and found a strange pig…
... . Obviously, since there's no circuitry on the data bus ... t be 4V but near 5V or 0V. I just ... test them independently of the Spectrum since they're simple ... the Vcc voltage on your Spectrum? [Vcc is the power ... -- or even on the Spectrum sockets for the IC23-26 ...First time capacitor replacementHi, I have an Issue 2 board, that i wish to start with recapping as advised on here, as they look to be all original. (Same with V3 board, but going…
... temporary connecting this point to +5V. This is just a test ... if you get the normal "no ROM" pattern on screen (example ... "]here[/URL]).
Most Spectrum failures (other than keyboard or ...Issue 3 board with strange piggy-back boardIn case you are interested. I?ve never seen something like this before. I have an Issue 3 board here. When I opened the case and found a strange pig…
... broken or the 12V and -5V are not available. Means white ... on my running Spectrum I recognized that there is no Ram test ...eBay 128K Spectrum RGB cables overheat the Spectrum!?Hi everybody, For a long time I've wondered why Spectrum 128K Toastracks were overheating when using my Retro Computer Shack RGB SCART cable. Today …
... ]I say again, though, no matter what anyone else says ... .[/QUOTE]
I see no reason why loading the CSYNC ... signal may be at maximum 5V. There is a 68 ... RGB socket of the 128k Spectrum. In worst case, if ... is ok and there is no positive current coming out ...eBay 128K Spectrum RGB cables overheat the Spectrum!?Hi everybody, For a long time I've wondered why Spectrum 128K Toastracks were overheating when using my Retro Computer Shack RGB SCART cable. Today …
... time I've wondered why Spectrum 128K Toastracks were overheating ... think the cost is my Spectrum 128K's ULA, and ... which of course is a no-no.[/QUOTE]
As ... I use a 1.5V AA battery for the blanking ... for any model of 128K Spectrum (or QL).
...Spectrum Missing -5vMy Spectrum is "almost" booting, just when you expect the (C) 1982 Sinclair Research to appear it just displays flashing squares on the screen :( I …
... speaker?
If the -5V supply is missing, there is ... power supply circuitry in the Spectrum. Do not power it for ... being operated without the important -5V supply. If they are not ... /> EDIT: or if you get no voltage, as [URL="http://www ...Spectrum Missing -5vMy Spectrum is "almost" booting, just when you expect the (C) 1982 Sinclair Research to appear it just displays flashing squares on the screen :( I …
... on a machine with no +12V or -5V is to switch out ... take out the other. The Spectrum service manual actually recommends switching ...ZX Spectrum and add-on temperaturesImre Jakli from Hungary sent me some interesting pictures which I think are worth to share. These are about temperatures he measured with a modern to…
... power switching regulator TSR1-2450 5V-1A
There were ... of the unloaded
15.5V was too low, and with ... .
That was influenced the -5V generation circuit. After the computer ... .5V the Spectrum was freezed... With the ISSUE3B
board I had no ...Spectrum +2A PSUI picked up a black +2A without a power supply. Looking on eBay the PSUs seem quite rare. The schematics for the PSU show +/-12 and 5v, would it be …
... the PSU show +/-12 and 5v, would it be possible ... working that wasnt the original spectrum one?[/QUOTE]
no-ip.org/public/spectrum/PSU.jpg[/IMG]
[IMG]http://alistairsserver.no-ip.org/public/spectrum/PSU2.jpg[/IMG]128K RGB Display problem.I have just got my hand on a toast rack, but when powered and connected to the telly the picture jumps horizontally at random intervals. Could it be…
... Pin 8 should be between 5V and 7V for a widescreen ... . Voltages less than 4.5V may switch off the SCART ... pin 16. If there is no wire, connect a red ... cell. Now see if your Spectrum displays a steady picture.
Spectrum's RS232 port pin 6 ...128K RGB Display problem.I have just got my hand on a toast rack, but when powered and connected to the telly the picture jumps horizontally at random intervals. Could it be…
... Pin 8 should be between 5V and 7V for a widescreen ... . Voltages less than 4.5V may switch off the SCART ... pin 16. If there is no wire, connect a red ... cell. Now see if your Spectrum displays a steady picture.
Spectrum's RS232 port pin 6 ...IF1bis StabilityI just thought I would start a different thread relating to the IF1bis, and leave the copyrighters to it elsewhere...:-P I've had mine for a few mon…
... absurdly high impedance. See Spectrum reset signal. Needs buffering ... and /NMI signals for the Spectrum.
[QUOTE]- ... machine having no internal power circuitry (supplied with +5V, -5V and + ... , occasionally caused by the Spectrum?s DC-DC converter, ...PlusDlite problems with 128K modelsLast year I developed the PlusDlite, and already shipped out a couple of them. Only recently I discovered some problems with 128K models. I remember…
... something to do with it: no difference when disabling or removing ... probably because of normal ZX Spectrum ROM routines.
[B ... in the PlusDlite, the ZX Spectrum resets when entering a keyword ... /> [B]7. Adding a separate 5V[/B]
Like on the ..."Freezes" on program loadingHi! I have ZX Spectrum+ (Issue 6A), and recently it has started to freeze w/o returning an error (but keyboard works) on program loading, regardless …
... confirmed that an issue 6 Spectrum can be forced to initialise ... pin 35 of IC27 at 5V during power on.
no clue.Loading from/saving to Zoom H2NI have recently acquired a Zoom H2N Handy Recorder for various audio-based purposes, and I am interested in loading my Speccy games from the H2N (Wav…
... -saving process).[/QUOTE]
No that is the wrong connection ... is also working because both Spectrum ports adress the same one ... is a comparator working with 5V that needs only very few ... for tape in of the Spectrum clone Harlequin.
Greets ...My new Spectrum +3 has no start menu.Hi all, I recently took delivery of my 'new' Spectrum +3 from a Fleebay auction. So I serviced the drive on Saturday as it had a snapped drive belt …
... reseted pulling pin 1 to +5V. That is, joining pin 1 ... Fleebayer sold it as a 'no returns accepted'. I now have ... class works!), but no de-soldering kit and no SED9420C. So I ... get my other purchase (a Spectrum + 128k) running while the rest ...PC to +3 communicationsHi I'm going to explore the abilities of my +3 to communicate with a PC. The "natural" ways to do that would be via serial or parallel link. I've b…
... the sound chip, there is no difference in function between the ... between a PC and a Spectrum, this can be a problem ... sending data to the Spectrum when the Spectrum activates the flow control ... . So you can connect a 5V TTL logic output to a ...
