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Spectrum 48K colour problemI obtained Spectrum 48K issue 2 in verry good condition. Machine work very good, but picture on my Samsung TV (72cm diagonal flat 100 Hz) is little s…
... round metallic trimmers on an issue 2 spectrum (2.2k each ... ). They are just below the ULA.
Adjust the lower one ... is known to happen on issue 2 spectrums. On latter speccy ... . If some components on the board shift (drift) on their valus ... -
True Spectrum laptop (no emulation)[url]http://user.tninet.se/~vjz762w/[/url] Hi All, I have build a speccy laptop, battery part is not ready yet.... I did it on 2 days, I will put s…
... how much it consumes.
ULA 6C consumes appr. 0,68W ... socket of a issue 4A speccu, with my ULA replacement:
10 ... .3v reg of the CPLD board is driven from the 9v ... -
Can you see the Spectrum......in this auction? [url]http://cgi.ebay.de/ZX-Spectrum_W0QQitemZ160246792691QQcmdZViewItem?hash=item160246792691&_trkparms=72%3A445%7C39%3A1%7C65%3…
... rather than the 'second ULA' that the later boards ... 'm 90% certain its an issue 4.
... Its definitely not an issue 2, as its missing the ... colour on screen when the ULA gets too hot.
... on issue 4.
(issue 3 had a green board top ... -
Issue 2 Board - CPU 'Patch'I've been wondering why my issue 2 board has been kicking out this signal when powered up... [IMG]http://www.drumfu.com/ResizedDuffIssue2.jpg[/IMG] …
... the IORQGE input to the ULA high whenever address line zero ... ][I]Issue 2 boards fitted with the Type 5C112 ULA have either ... is my speccy an issue 1 board marked as issue 2?[/QUOTE]
Issue 2 Board - CPU 'Patch'I've been wondering why my issue 2 board has been kicking out this signal when powered up... [IMG]http://www.drumfu.com/ResizedDuffIssue2.jpg[/IMG] …
... revision of the ULA fitted in the Issue 2 board and it's ... I should now strip the board for parts...Timex 1000 PAL conversionHi, a friend of mine sent me a Timex 1000 from the US. I was prepared for the NTSC/PAL issues so no surprise came to me when i got a shadowy dark scr…
... could this be a faulty ULA. Mine has a 2C183E 8236 ... problem) and the Timex1000 board is an issue 3. Its not just ... also something weird on its board... i cant find a physical ...128k heat sink - ULA problems and a hintHello, I had two ZX Spectrum 128k with a similar behaviour. One item worked only a short time after switching on and then there were increasing RAM …
... , rather than a dodgy ULA chip. The ULA gets quite warm anyway ... the heatsinking on the standard issue 3+ 48K isn't brilliant ... , and is worse on an issue two board. Feeding the Spectrum with ... this wouldn't be an issue on a 128K machine, it ...128k heat sink - ULA problems and a hintHello, I had two ZX Spectrum 128k with a similar behaviour. One item worked only a short time after switching on and then there were increasing RAM …
... sure sounds like a duff ULA that disfunctions after heating up ... ;329876]Maybe, but consider that ULA is also responsible for key ... , rather than a dodgy ULA chip. The ULA gets quite warm anyway ... , and is worse on an issue two board. Feeding the Spectrum with ...4116 DRAM for 48KSomeone told me I got faulty RAM in my broken 48K. They should be 150ns, right? What would be a good place to buy them from?
... ULA. It came that the ULA I was using is a -7 issue ... a earlier PCB (an issue 3B), and the RAS/CAS ... famous double inverter in issue 6A). Replacing the ULA with a -6 ... problems assocaited with specific ULAs/board issues.
-- Richard4116 DRAM for 48KSomeone told me I got faulty RAM in my broken 48K. They should be 150ns, right? What would be a good place to buy them from?
... a particular Spectrum issue board, and a particular version ULA. Other than that ... works for other issue boards, or other version ULA's. For ... Spectrums available, most with same ULA inside.
[quote ... ROM onto the data the ULA is reading for the ...Keys don't work even with new membrane, HELP!Hi folks. I have a 1983 48k Zx Spectrum. It powers up fine, but none of the keys respond. I have tried fitting a new keyboard membrane from rwap, but…
... you probably have an Issue 2 board, so here's the ... url]
Note the ULA - IC1.
Note ... the relevant pin on the ULA with a multimeter - ... relevant pin on the ULA, and the other probe ... the keyboard connector and the ULA. But...
...Keys don't work even with new membrane, HELP!Hi folks. I have a 1983 48k Zx Spectrum. It powers up fine, but none of the keys respond. I have tried fitting a new keyboard membrane from rwap, but…
I have a spare ULA chip if you need one by the way...... PM me an address to post it too. Oh, and I'll need to know the issue number of the board too - somebody said it was Issue two?New Guy Wants Speccy - SWAP !Hi, I`m new here so here is a little background info ! I always had a C64 when I was in my teens in the 80`s, my friends had Spectrums, so it was alw…
... much any component on the board - except the modulator, since you ... ZTX transistors, Z80, ROM chip, ULA..... Pretty much anything could have ... to swop you a working board for your duff one. I ... it'll be the same issue tho.Keys don't work even with new membrane, HELP!Hi folks. I have a 1983 48k Zx Spectrum. It powers up fine, but none of the keys respond. I have tried fitting a new keyboard membrane from rwap, but…
[QUOTE=DEATH;335390]I have a spare ULA chip if you need one by the way...... PM me an address to post it too. Oh, and I'll need to know the issue number of the board too - somebody said it was Issue two?[/QUOTE]
PM sent :)Keys don't work even with new membrane, HELP!Hi folks. I have a 1983 48k Zx Spectrum. It powers up fine, but none of the keys respond. I have tried fitting a new keyboard membrane from rwap, but…
... ]Before you condemn the ULA, it could also be ... has crashed or the ULA has stolen the buses. ... I notice from the Issue 2 schematic that the ... resistors. I think the ULA must have open-collector outputs ... everybody's reference, the board says (c)1983 issue 4A.......SRAM replacement for lower 16KSome time ago I wondered if it were possible to replace the lower 16K RAM of a 16K/48K Spectrum with a single SRAM chip. You know, those pesky 4116 D…
... work with different ULA's, SRAMs and different issue boards, [I ... on a separate (experimentation) board. In that case, place ... everything directly on the Spectrum board. Construction should be easy, ... check the schematic of your issue board, and find the parts ...Component count/modern replacementsThere is a thread/project for replacing the old memory with simms There is also the ULA replacement. There's DEATH's composite replacement. What els…
... ]Not sure when the issue 6 pcb was unleashed ... was an improvement on the issue 1, neater, less components ... moved on that a new board would be an improvement. ... for the explanation!
Issue 6 had a number of ... standard chips replaced by an ULA. IMHO this is not ...Issue 3B problemHi! I have an issue 3B board that is having a strange problem: when I got it it didn't had the -5V and +12v, as usual. After replacing TR4 and TR5 t…
... would indicate a problem in ULA or video encoding circuitry.
issue) Spectrum, and see if that ... reverse too: take the (working) ULA from that other Spectrum, and ... it in your non-working board.
At that ...Pera Putnik's RGB interfaceI am sure some (if not many) of you will have seen Pera Putnik's RGB interface [URL="http://members.tripod.com/%7Epiters/uvyrgb.htm"]circuit diagram…
... you can get from the ULA. (HIGH frequencies are reduced by ... noise using edge connector. On Issue 3 board in good condition, and ...What we gotI moved house and I have setup my Spectrum gear, I was looking at all that I have and was thinking what else do others have in there collection? Ok …
... mode regulator)
1 +3 (issue 1), the one I use ...
Issue 4S main board in working order
Issue 4 main board with ... 4116 chips
1 spare ULA for the 48k
A ...Pera Putnik's RGB interfaceI am sure some (if not many) of you will have seen Pera Putnik's RGB interface [URL="http://members.tripod.com/%7Epiters/uvyrgb.htm"]circuit diagram…
... connector of a 48k+ with issue 4b board. The picture of my ... rubber 48k (issue 2) is similar ... area because of differences in ULA versions without need of adjusting ... termination of the ULA signals. The test board (contains about 50 ...zx81 help neededHi, I got a ZX81 today supposedly in working order, it was for the first two minutes, but after that the keyboard produces the wrong letter, number …
... reparied one TS1000 ( it had issue 3 board) with this fault. The ... transistor amplifier the clock that ULA generated. No Q1 no clock ...Spectrum Video Circuitry.Wotcha, I've looking at the circuit diagram of the speccy video circuitry (Hey, I'm snowed in, and theres only so much Civ IV i can stand :p), and I…
... bypass the transistors between ULA and the composite video ... allow for a different ULA and/or video encoder ... right... I checked an issue 4B board, but didn't find ... purpose of VCC2 from the ULA?[/QUOTE]
Looks ... the circuitry around this ULA Vcc2 pin, I'd ...Flicker fixer for ZX 48KHas anyone the schematics for the flicker fixer: [URL]http://8bit.yarek.pl/computer/zx.48/[/URL] Micky
... Pictures belong to a 4B issue board, but this will do in ... the resistor. Check the ULA is firmly socketed and ... br /> Take off the ULA again. Take the transistor ... the test program. The ULA snow shouldn't happen ... resistor that is connected to ULA pin 36.
[ ...Spectrum Serial Numbers Wanted!![b]This post updated Sept. 26, 2013[/b] As far as I know, the serial numbering system for the Spectrum has never been fully worked out. For the p…
... No.1 says regarding Issue 4A: "Two spare gates ... been used to improve ULA timing. It is important ... always understood that this ULA needed the added delay. ... (circuit) needs the new ULA....
Still a 6C001 ... in my unmodified 3B board for many years now, ...What do you think about this ?It seems in near future this multi-role board will be able to mimic Speccy too.... [url]http://www.retrothing.com/2009/04/fpga-arcade-replay-emulati…
... easily coded in small logic. ULA was implemented using just TTL ... implemented in Spartan. The only issue is about exact timings, which ... about "clone". Probably Chris behind ULA book is close to real ... approximation like in this nice board:
[url]http://www. ...Timex 2048 documentsHi, I got Timex 2048, seems to work, but no colors on screen :cry:. Neither TV out, nor Composite works. ULA fault ? It seems TC 2048 uses MC 1377 a…
... other users.
Issue 2 I mentioned previously ... issue 3 as marked on board, however matches logic for issue ... /tc2048_5c.JPG[/url]
Issue 5d:
[url]http ... see there were two ULA revision used in TC2048 ... am going to draw ULA schema first with pins, ...Issue 2 issue (...)Just acquired an issue 2 Spectrum 48 K, selled as working board, not working keyboard. Before testing it with a psu I opened the case and discovered …
... issue 2 board acquired in the same batch, is mounted an 5c112 ula ... ....:???:
And on this board a terminal of resistor mounted ... the 2 ulas on these issue 2 boards....:???:
@ ... mounted on a miniature board and spider. This ULA
was fitted ...Issue 2 issue (...)Just acquired an issue 2 Spectrum 48 K, selled as working board, not working keyboard. Before testing it with a psu I opened the case and discovered …
... issue 2 board acquired in the same batch, is mounted an 5c112 ula ... br /> And on this board a terminal of resistor mounted ... 2 ( socketed) ulas on these issue 2 boards....:???:
@ ... mounted on a miniature board and spider. This ULA
was ...
