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ANN: SP1 for Z88DK (aka splib3, Sprite Pack v3.0)Well it's finally arrived, after a month of "a few days from now" release deadlines. SP1 is the lastest version of splib, a flicker-free software sp…
... :- non-maskable interrupts (NMI) and maskable interrupts (MI). Both kinds ... snapshot button) that pull the voltage low on the /NMI ... the interrupt vector table in RAM and arrange for our own ... mentioned above, reads the keyboard and updates FRAMES.
... -
Best replacement for ZTX650?What is the best replacement transistor for the obsolete ZTX650? I've read that TIP31 will do the trick. Is there a decent equivalent from the BC or …
... br /> In addition to the RAM, also check:
TR5 ... it from the board, and measure that the 2 windings ... I hope its the RAM because if its not it ... rather unusual for bad RAM to cause such a ... spectrum has the same transistors and voltage regulator (7805) as a ... -
Zx Spectrum Laptop (again)I've been reading all the old treads about a possible portable speccy. I even found the one about the Speccy Laptop. But it seems there's a lot of ne…
... different voltage problem.[/quote]
Hmmm... Internal TV Tuners (and ... rid of the old-style RAM and replace them with a couple ... effects achieved by lack of RAM refresh will be lost ( ... times. Old RAM drains lotsa power.
And what about ... -
Zx Spectrum Laptop (again)I've been reading all the old treads about a possible portable speccy. I even found the one about the Speccy Laptop. But it seems there's a lot of ne…
... modern CMOS Flash device, and replace RAM with a single CMOS ... flash rather than static RAM and so retains its configuration ... SOIC surface mount packages for RAM and ROM. These are still ... even get the heatsinkless voltage regulator hot) and very, very cool :-) -
toasted soeccysHello, ive jsut bought a pair of speccys on ebay (one 16k issue 2 & a prob 48k issue 3) unfortunaly the genius who sold them tried to see if the wor…
... here - such as the input voltage will always be -
Unconventional way of diagnosing a faultHi everyone Some time ago I got a 48k Spectrum (issue 3B board) in a pretty bad condition. I believe the power supply transistor TR4 failed, causing…
... to the 4116 memory, and check the +5v supply ... 0 (or maybe the voltage changes by something less ...
Since the 4116 RAM would have likely been damaged ... desolder all the 4116 RAM and put them in sockets ... t be fully functional and lower RAM can be completely ... -
Unconventional way of diagnosing a faultHi everyone Some time ago I got a 48k Spectrum (issue 3B board) in a pretty bad condition. I believe the power supply transistor TR4 failed, causing…
... to the 4116 memory, and check the +5v supply ... 0 (or maybe the voltage changes by something less ... /> [QUOTE]Since the 4116 RAM would have likely been damaged ... desolder all the 4116 RAM and put them in sockets ... be fully functional and lower RAM can be completely ... -
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…
... much better static protection and latchup protection than older ... very robust, and provides an extremely stable output voltage, so I ... use a modern CMOS static RAM (and a little glue logic) ... going around and replacing perfectly good 4116 and 4532 memory.< ... -
building a PCIv'e decided to get my old PC and try and get the thing working again. not really sure what went wrong with it, and instead of buying a new one i pre…
... standards.
PC133 RAM is a technology called SDRAM ... last five years use DDR2 RAM; and the latest boards use DDR3 ... which runs at a lower voltage. Your motherboard is old enough ... way, buying the separate components and assembling them yourself won't ... -
ZX Spectrum Power SupplyHi All, I've come across a power supply that is currently registering 14.5v before it is plugged into the Speccy. I have another one that registers…
... /> This produces -5v and +12v for the ram, and +12v for the Colour ... 4116's with something else, and hack something for the colour ... ticking over alternator puts horrendous voltage spikes in there), however, I ... -
ZX Spectrum 48k issue 3b power problem?Hi :) I was lucky enough to find a couple of ZX Spectrums at a car boot sale yesterday. I spent the evening fiddling about with one (issue 2) and t…
... think you have any faulty RAM chips.
You can use ... to 15 volt unregulated DC and the Spectrum regulates this to ... then it starts to fail and voltage drops causing the malfunction you ... see, eventfully the voltage will drop below the level ... -
Dead Spectrum SocietySo I'm getting back into real Sinclair computers rather than emulators. During the summer months I was lucky enough to buy a working ZX81 and was giv…
... least not before replacing 7805 and/or transistors in +12 ... Lower RAM and +12/-5V problems are often related, like voltage conversion ... circuitry busted -> lower RAM chips dead ... further tests. The lower RAM chips are a lot ... -
Repairing a faulty 48K issue 2.I am investigating one of a pair of non-working issue 2 48K Spectrums that have been sitting in a cupboard untouched for quite a few years. I haven…
... decent looking signals on A0 (and the other address bus lines ... will next remove the lower RAM and fit sockets. I would think ... I found was a dead voltage regulator. -
Issue 2 voltage troubleDear all, I got my hands on an old issue 2 from a friend. Price was close to zero so I did not hesitate to take it. After powering it up I was sur…
... a faulty ram draws to much current and causes the voltage drop. ... 680mA from power supply and voltage drops from 12.8V ... fully blown TR4 and thus a faulty lower Ram -> non ... working Speccy.
- replace 7805. The voltage and ... -
Colour blocks on displayHi all, I have just acquired another Sinclair product, my first one being a C5, it's a 48K ZX Spectrum. It shows colour blocks on the display when p…
... DC meter readings within the voltage converter circuit. It's ... too low and would suggest that either the voltage converter circuit ... is /CAS for the lower RAM and attaching a voltmeter to it ... on getting the voltage converter working properly and finally you'll ... -
MB02 picsI got an original MB02 from someone to fix, and of course I made some pics to share (click for magnification): [URL="http://benophetinternet.nl/hobb…
... the TTL chips tolerate higher voltage without damage. The higher integrated ... especially check DMA, WD, S-RAM and 74LS93 that divides the clock ... switch of MB02+'s ROM and enable Speccies ROM to be ... -
Diagnosing a strange software fault in a 48kHi, A friend gave me a 48k, which I am very keen to restore. The spectrum 48k was my first computer over 20 years ago and I owe my ability to code t…
... /RAS signals for the upper RAM and so the ROM code will ... lower 16K of RAM. The output of the voltage regulator or pin ... -
Diagnosing a strange software fault in a 48kHi, A friend gave me a 48k, which I am very keen to restore. The spectrum 48k was my first computer over 20 years ago and I owe my ability to code t…
... /RAS signals for the upper RAM and so the ROM code will ... lower 16K of RAM. The output of the voltage regulator or pin ... wav file on my laptop and playing it with mplayer). But ... -
Altera CPLD vs Xylinx FPGAI will dig into the world of FPGA's, mainly to find something that can replace one or more GALs for my current and new projects. And it's never bad t…
... it gets cumbersome quite quickly and Verilog or VHDL become ... to do something to shift voltage levels, so always make sure ... the switching fabric and lookup tables are all RAM-based. However, ... amount of fast dual-ported RAM, and also the CLB look-up ... -
The new Superfo cloneHi In the spanish forum speccy.org some guys and me have optimized the superfo clon to have less ICs. The actual design has 39 ICs versus the 45 ICs…
... intentionally in series and have nothing to do with voltage levels ;-)
You've missed picking up (and it ... circuit to access the video ram and the Z80 to access the ... is coupled to the video ram through resistors, in this ... -
Issue 3 board... How to resurrect?Dear Everyone, Now I have a working 48k Issue 3, a sort of working Speccy+ (still having problems with the keyboard, more of that in another post) a…
... sleep, I have gone through and done all the readings again ... seems fine with the lower RAM and the Voltage regulator. Looks like the ... />
Voltages on the lower RAM now are:
0V Pin ... : 12.06V
And on the Voltage Regulator I get:
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 …
... busy sorting out the voltage regulator, TR4 and Coil on the issue ... fine to all the lower RAM, and the copyright screen looks top ...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 …
... with volts, resistance, diode and transistor testing. I'm ... Keyboard Membrane and z80 with confidence, lower RAM with less ... Zorn's replacement Lower RAM boards in the ... none of the lower RAM chips are heating up ... the TR4, coil and voltage regulator for any nasty ...Poorly Issue One 16k spectrum diagnosis?Hello, everyone. :smile: I was lucky enough to buy an Issue One 16k rubber key the other week; I didn't know it was an Issue One till I opened it up…
So.... the RAM is now socketed and the Speccy is composite modded ... OK. Have tried the original RAM and a NOS set of (according ... the seller) tested and working 4116 chips, and still get the original ... / high voltage I'm not detecting that's murdering the RAM we ...ZX Spectrum 48K working as 16K from factoryGood morning I Have a Zx Spectrum 48k working as 16K , it came like this from factory. What can i do to solve this , and put it to work as 48K? Wha…
... /RAS signals for the upper RAM and so the ROM code will ... lower 16K of RAM. The output of the voltage regulator or pin ... RAM test program would probably then load and run.
Or/and ... try these commands and report the results:
Issue 4A repair attemptI think I need some help. I have a nice Issue 4A main board here, which does not give out any video signal. I checked some voltages (the ones that se…
... and a powered off Spectrum and I did all the measurements. The voltage ... regulator, the coil, the entire lower RAM and TR4/TR5 ...Harlequin clone...PCB manufactured!Using Chris Smith's detailed schematics and project notes from the Harlequin... a Speccy fan in the United States by the name of Don (Superfo) has de…
... be measured.
Using static RAM and HCT/HC logic ICs the ... output of harlequin is RGB (!) and composite (by an AD724). ... SCART signal including sound and video switching voltage.
The first ... seem to be very stable and compatible.
Greets ...Linking spectrums - parralel processing is it possible?Was there any way to do this, (excluding disk, tape and microdrives)?
... of) upper 32K and replace with shared RAM/ROM.
Part ... -only for CPU 1 and read-only for CPU ... 2.
And vice versa.
... could use dual-ported ram with some logic to ... with enough ram and i/o and able to handle the voltage?
...Linking spectrums - parralel processing is it possible?Was there any way to do this, (excluding disk, tape and microdrives)?
... , one could use dual-ported ram with some logic to pull ... with enough ram and i/o and able to handle the voltage?
and it could be done with ...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…
... is using to detect RAM (and subsequently set the 23733 ... -up so if the voltage of its output is ... circuits detect a low) and lower than 2.2V ( ... confused.
Now, that RAM upgrade *could* require the user ... check the ROM disassembly and see if that can ...
