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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 …
... he said he tested the 7805 afterwards and it checked out ... -
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 …
... (usually an IC similar to 7805 but producing 9V).
If ... -
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 …
Spectrum power supplies aren't stabilised (regulated). An unloaded Speccy power supply will put out something like 12 volts (the supply is labelled 9v). The 7805 in the machine does all the regulation. -
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 …
... supply is labelled 9v). The 7805 in the machine does all ... V is sufficient for the 7805 to do the +5V regulation ... -
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 …
... ]
The fact that 7805 doesn't have a shortage ... and measure voltage produced by 7805. It should be 5V of ... measure voltages before and after 7805. It's likely that at ... -
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 …
Regarding the 7805 issue: If the 7805 gives 5 V on pin ... ), it's OK. If the 7805, after a while, gets too ... V DC. If replacing the 7805 gives the same result: Some ... other parts than the 7805 is faulty. -
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 …
If 7805 gives 5V but gets overheated, it's usually okay itself but overloaded by shortage in cirquits that powered up from it. -
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 …
... to replace it ! Simply disconnect 7805 output pin (the one with ... -
Preferred way of determining Y co-ord in assembly?I know of 2 ways of calculating the y-cord of a pixel row for the speccy in assembly. One is to calculate the address by ways of shifting and masking…
... the sprite, I use my STEPDOWN macro to bump HL down ... line:
[code]
#DEFINE STEPDOWN INC H\ LD A,H ... -
+3 Sound Mod.Hi All, I am very much a novice when it comes to building electronics, but I thought I'd have a go at [url]http://www.geocities.com/sinclair_bitz/st…
... the output.
A 7805 needs at least 7v to ... not correctly feed (well, a 7805 with inverted polarity blew up ... -
ZX Spectrum 48K +Hi, I have a ZX Spectrum 48K + which I bought like a million years ago (1984) My Spectrum has been out of duty for quite some time and I guess I ke…
... out,some transistors inside and 7805 chip.
b)z80 ... -
Does anyone have any working Ferranti's?Does anyone know where I might get hold of a Ferranti ULA5C112E-3?? I think this is the problem with one of my rubber key 48K's as it otherwise wor…
... a bit thicker than the 7805 heatsink) and made many ula ... -
Voltage SchmoltageOk then. Don't flame for wanting to use a C64 tape deck for this - it was the only one I have to hand which may be cannibalised for the purpose. So …
... series diode (1N4007) from a 7805 regulator ground pin down to ... /> [code] +-----+
| O |
+-----+
| 7805|
| |
+-----+
| | |
+12 ... -
Voltage SchmoltageOk then. Don't flame for wanting to use a C64 tape deck for this - it was the only one I have to hand which may be cannibalised for the purpose. So …
... /> [code] +-----+
| O |
+-----+
| 7805|
| |
+-----+
| | |
+12 ... -
Voltage SchmoltageOk then. Don't flame for wanting to use a C64 tape deck for this - it was the only one I have to hand which may be cannibalised for the purpose. So …
... question time, then: what is 7805 actually regulating? both of those ... -
Voltage SchmoltageOk then. Don't flame for wanting to use a C64 tape deck for this - it was the only one I have to hand which may be cannibalised for the purpose. So …
... question time, then: what is 7805 actually regulating? both of those ... -
Eprom blowerdoes anyone know a site with plans for an eprom programmer project that'll blow 27C256s. I attempted to build one called Kisseprom, but the software …
... , depending on type.
The 7805 is powered from the external ... -
ZX81 power supplyFriend gives me ZX81 without power supply and i want to test whether he work or not. Can i use Spectrum p.supply for that purposes? I dont want to d…
... , as the ZX81 has a 7805 regulator to bring the input ... -
spectrum PSU'sI've read contradictory info on which psu(ie amp rating) is for which spectrum. :confused: The models and amp ratings are 1.2A, 1.4, 1.85 and 48k, …
... ) is a voltage regulator, the 7805. It's a pretty easy ... ".
Note that the 7805 chip (it is an integrated ... than around 7V (for the 7805) reference ground, the device won ... -
ZX81 power supplyFriend gives me ZX81 without power supply and i want to test whether he work or not. Can i use Spectrum p.supply for that purposes? I dont want to d…
... and "grey" +2.
- Minimal 7805 heat dissipation ! -
spectrum PSU'sI've read contradictory info on which psu(ie amp rating) is for which spectrum. :confused: The models and amp ratings are 1.2A, 1.4, 1.85 and 48k, …
Another thing, is that an unregulated PSU will give more ripple into the Speccy, and so make the 7805 "work harder" to compensate for this, which will lead to even more heat. -
PC Power supply for SpeccyHi all, after 13 years with out playing spectrum games I am eager to play the old games. Thus I got up to the garret checking my old stuff. Two of m…
... peripherials (which utilize regulators like 7805 to make own power out ... -
48K Speccy not workingHey, A few months ago (hope it´s not to late) I was loading a game into my speccy and from one moment to another it stopped working! I unplugge…
... the 3rd pin in the 7805 chip is´t the same ... -
I want to build a new, super spectrum ;-)only kidding Andrew :-) my brain's going at a mile a minute at the moment, so I thought I should put some of the ideas down in case one of them is w…
... vastly more efficient than a 7805 regulator, and will generate very ... sink). Having said that, the 7805 is very robust, and provides ... rushing to replace it. The 7805 has built in thermal and ... -
I've got a divIDE. Now what?I've purchased a divIDE and after a month it's at home. What can I do now with that? I've got a 48k+, a +2B and a +3. The +2B has the original ROMs,…
... interface has it's own 7805 reg yes, but the drives ... -
PC power source and Spectrums.I'm planning to use a basic PC ATX power source (300W) for all my sinclair equipment, but I have two questions: - I've read about some nasty things …
... +12v and relying on the 7805 (I think it will overheat ... ), using +5v and bypass the 7805 or use another voltage regulator ... -
PC power source and Spectrums.I'm planning to use a basic PC ATX power source (300W) for all my sinclair equipment, but I have two questions: - I've read about some nasty things …
... 9V anyway.
The 7805 regulator needs at least 7V ... -
Broken 128+2 :(Just got my eBay Speccy through the other day, plugged it in and everything but the red light on the keyboard doesn't come on and there's no connecti…
... supply. If good check the 7805 regulator IC and this +5V ... -
Broken 128+2 :(Just got my eBay Speccy through the other day, plugged it in and everything but the red light on the keyboard doesn't come on and there's no connecti…
... 't cure it, the regulator 7805 which is mounted on the ... -
Interface rom - Need help to dump itHi, I have temporarily an interface that is similar to a multiface. It has an NMI button and displays a menu where states can be saved and pokes ent…
... . Is it possible that the 7805 is not working correctly? I ...
