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Problem with Spec 128k +2 !! Noob calling for help!Hi there, I have an spec 128k +2 which was working fine, played with him yesterday and today when i tried him again he gave me this [URL="http://go…
a typical crash... failure of ram, ula or anything :P
(we got those answers from this forum all the time) -
Any interest in new low-cost mass-storage interface with 512K RAM?I've recently added support to ResiDOS and the +3e ROMs for SD/MMC card interfaces; in particular, ZXMMC (which has no onboard RAM and so is only sup…
... to crate a non-volatile RAM disk one of the best ... /> It works like normal static RAM (no burst mode) but retains ... and some logic to select upper or lower byte and interface ... -
Spritual successor to the Speccy1988-1995 - Atari ST/STe/Falcon 1995-2000 - ? hmmm ? 2000-2006 - Playstation 2 with a keyboard 2007- ?
... but it was a massive failure.[/quote]
The funny ... , forget the 24K of screen ram that needs to be moved ... useful then that 512K of ram, 16 switchable screens to play ... -
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…
... 16K pages), single 512K static RAM (I think this can be ... the voltage regulator in the upper left doesn't even have ... -
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…
... other supplies and removed last. Failure to observe this precaution will ... to system use, where failure of the Vbb supply must ... and GND to the 4116 RAM with the +12/-5v ... likely to fry your lower RAM! Hideous devices, these 4116s... ... be replaced with static RAM! -
TV Modulator. Can it be repaired?Is it possible, to repair tha TV modulator (after removing it) if it gives wavy picture? I replaced both transistors (tr1/2) and both electrolytic ca…
Won't initialize above 16K RAM - well, either A15 on the ... the chip select for the upper 32K is fried. It's ... between the lower 32K and upper 32K based on the state ... -
TV Modulator. Can it be repaired?Is it possible, to repair tha TV modulator (after removing it) if it gives wavy picture? I replaced both transistors (tr1/2) and both electrolytic ca…
... than the 7805, but the upper 32K RAM runs off just +5v ... -
Anybody fancy coding this?blah de blah de blah Please ignore, poting error.
... , with the top of physical RAM (PRAMT) being set at 32768 ... lines.
consider dodgy Ram chip A.
Setting ... (both bytes in the same ram chip) the program outlined above ... 170 sets the whole of upper memory to 170, again the ... -
Anybody fancy coding this?blah de blah de blah Please ignore, poting error.
... keeps going to the same Ram chip when a fetch or ... should be going to an upper memory chip the program won ... always going to the same RAM chip ........
HMMMM .... it ... -
Anybody fancy coding this?blah de blah de blah Please ignore, poting error.
These days, use flash - don't bother with eprom. You can replace the ROM by making an external board that connects to the edge connector, and nails ROMCS high just like ZX Interface 2, so that the on-board ROM never gets selected. Simple decoding logic ... -
Dead +2B, help required...It was bought defective on ebay. It came with two faults: a "dead" power supply (it was the fuse) and a faulty main unit. The power supply is now re…
... while, it seems IC5 (left RAM circuit, a 4067-10) gets ... trying to discard every possible failure before getting the "ULA dead ... -
Dead +2B, help required...It was bought defective on ebay. It came with two faults: a "dead" power supply (it was the fuse) and a faulty main unit. The power supply is now re…
Well, I've replaced the RAM: I changed all 4067-10 ... with a white border (previous failure was black with black border ... -
Spectrum 48K ROMHi Can anybody help I have an Issue 6a Circuit Board which has a faulty ROM Chip. Is it possible to program a ROM Chip with the 48K ROM and fit it as…
... 6a circuit board has the RAM selection jumpers for OKI and ... middle of the board the upper one is marked [B]IN ... holes, at the moment the upper two [B]IN[/B] holes ... are bridged and the upper two [B]Out[/B] holes ... -
Testing RAM Chips After RemovalHi I am going to use Winstons Hot Air Gun method of removing the RAM chips from a 4S circuit board. I wish to check the RAM chips, I have a Logic Pr…
... />
which will show up RAM errors in the lower part ... higher part, the upper 32K and the bank-switched RAM. And you ... press the red button. Bingo RAM and ULA I/O diagnostic ... -
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…
... /+5v supply at the 4116 RAM is a convenient place to ... .
Incidentally, on bad RAM, don't bet on flashing ... 't forget that the 4116 RAM is arranged such that there ... per data line. If the failure is such (which seems reasonably ... -
InterfaceHi I'm building a spectrum emulator. I've tried to build it as modular as possible, for example I have a zx class that have input and output devices…
... a Spectrum (both ROM and RAM) has what are known as ... 16K bank or upper 32K bank (the way the RAM gets selected ... -
UlaI remplaced an ULA 6c001-6 by an ULA 6c001-7 chip on issue 3B board. It is "crucial" to remove R32 and adding the 2x NAND gates ??? or not ? Thanks.
... am after a 48K spectrum RAM chip: [B]TMS4532-4[/B ... the lower bank to the upper bank, and from the ROM ... -
Disable onboard memoryWould this work...? Access to onboard I/O can be disabled by holding IORQGE high. Would it be possible to create a MEMRQGE in a similar way to disa…
... the onboard RAM. (I'm only thinking about the upper 32K which ... -
Yesteryear's Computers.Ahhhh ... [URL="http://www.computerworld.com/action/article.do?command=printArticleBasic&articleId=9023960"]back in the day[/URL] when a 300mb system…
... mobo (XT clone), with 1MB RAM, monochrome graphics, 12" amber monitor ... created a 360KB RAMdisk (on upper memory) so I could load ... -
Poorly Spectrum + Fault diagnosis help needed!Hi, I've got a Spectrum+. Sometime in the past I broke it and sent it off to be fixed. It came back working good as new, but with an issue 2 board i…
[QUOTE=swift240;202206]Just had a look at the old style C64 diagram the RAM chips in those are 4164.[/QUOTE]
You can use those in the UPPER memory block. -
Poorly Spectrum + Fault diagnosis help needed!Hi, I've got a Spectrum+. Sometime in the past I broke it and sent it off to be fixed. It came back working good as new, but with an issue 2 board i…
... anything. This could be a failure mode of the ROM, the ... Spectrum then you have bad upper memory. You'll also get ... -
more Spectrum uploadsHI all, just to let you know I've added some more stuff, including a white spec +, more keyboard development sketches for Geoff, Alpha Numeric pad, …
... a fairly high failure rate in silicon manufacturing of RAM, so instead ... as one device. Faulty / Dead RAM segments were disabled, leaving a ... -
more Spectrum uploadsHI all, just to let you know I've added some more stuff, including a white spec +, more keyboard development sketches for Geoff, Alpha Numeric pad, …
Interesting! I take it that this concept hasn't found its way into the modern RAM processing industry for whatever reasons? Probably b'cos the failure rate is much lower now I suppose... -
Project: M.u.l.e.Wokani came up with a great idea about trying an open-development approach for spectrum games, and I thought why not try with a game I have under dev…
... ". However we must still allocate RAM for this array with a ... plot g_land[45]". All such RAM allocated to gobal variables with ... ,4]. You will find the upper part of these ranges in ... using the amp2[] array containing upper ranges for all 9 outcomes ... -
Poorly Spectrum + Fault diagnosis help needed!Hi, I've got a Spectrum+. Sometime in the past I broke it and sent it off to be fixed. It came back working good as new, but with an issue 2 board i…
Thanks to the kind RAM chip doner, I got the ... that I discovered that my upper 32k wasn't working. Using ... a speccy with dead lower RAM. :???:
I think this ... -
+2B problem stillHi all, I have a spare +2B that still dont work. Richard kindly sent me 4 x 4464 ram chips but the +2B still dont work I have swapped over both ROM`s…
Oh well, that means I have 4 RAM chips, 1 Z80, 2 ROM`s, 1 upper case, 1 lower case, 1 Tape deck.
Couldn`t find the partridge in the pear tree. -
Question on Z80 R/W cycles.Snipped from the complete spectrum ROM disassembly: [CODE] Now the memory is checked. 11DA RAM-CHECK LD H,D Transfer the value…
... ).
To test whether RAM is present at all, all ... ... there's lots of interesting failure modes of the DRAM in ... -
Question on Z80 R/W cycles.Snipped from the complete spectrum ROM disassembly: [CODE] Now the memory is checked. 11DA RAM-CHECK LD H,D Transfer the value…
... errors, such as a partial failure internally with the row/column ... idiot tried a ZX-81 RAM pack on it - after which ... idiot with the ZX-81 RAM pack was me by the ... -
Speccy just snuffed it while playing 3D Pinball :(I have two speccys but the one I use most has just given up the gost! :-( game froze up and now all I get is flashing patterns and lines:-( Everyt…
... - all working bar the upper 32K RAM since one of the chips ... -
Speccy just snuffed it while playing 3D Pinball :(I have two speccys but the one I use most has just given up the gost! :-( game froze up and now all I get is flashing patterns and lines:-( Everyt…
... - all working bar the upper 32K RAM since one of the chips ...
