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Black paper, white border. Ram fault?We have a speccy that wont work properly. When we power it up, we get white border around a black screen. We swapped the rom and ula with a working o…
We have a speccy that wont work properly. When we power it up, we get white border around a black screen. We swapped the rom and ula with a working one, and we got the same result.
is this a ram fault? How can we check ram chips? -
Spectrum Issue two problemI managed to bring back to life a issue two spectrum (at least the power supply cirquit). The screen is now crystal clear (after replacing all the el…
... example.
I changed the ULA with several others to no ... -
Blowtorch method of Speccy repairsI just did my first Spectrum repair (and successful at that). It was the Issue 2 spectrum I wrote about a while ago, I just hadn't got around to doin…
... .
I removed the ULA. The fact this chip is ... fails again). I replaced the ULA, plugged it in... and I ... -
I/O contention model questionHi everyone, Sorry for my poor english. Together with a friend we are working on ZX Spectrum 48k implemented in FPGA. We have found bug in the Spect…
... cycles)
During _reading_ from ULA this can't be right ... -
New Spectrum emulator for DS[url]http://zxds.raxoft.cz/[/url] [quote]Features already implemented: * Solid Z80 core - possible bugs aside, the Z80 emulation is as complete…
... lines at the times the ULA would read them. It looks ... -
It's fitting...... that in the very month that the 25th anniversary of the Speccy falls on, I'm just finishing up making my first ever Spectrum peripheral. It's a …
... might be suspect) or the ULA (which might also be suspect ... -
Spectrum 48k SeettingGot an issue 2 speccy on the bench that had a poorly ula, changed that, also changed tr4 and tr5 (had no oscillator) now it just resets over and over…
... bench that had a poorly ula, changed that, also changed tr4 ... -
TIPP31 transistor questionYesterday I had the time to try and repair a 4S issue 48k spectrum I had. First of all I replaced all the electrolytic capacitors. The tr4 transistor…
... boot. I had tryied the ULA on another machine and it ... -
Is Ferranti still alive ?And if not......why should there be any restrictions on manufacturing the ULA ?
And if not......why should there be any restrictions on manufacturing the ULA ? -
Russian clone of ZX-Spectrum 48kThe classic russian clone of ZX-Spectrum 48k [URL="http://sblive.narod.ru/ZX-Spectrum/Leningrad48k/Leningrad48k.htm"]http://sblive.narod.ru/ZX-Spect…
... with simple logical compoments! no ULA chip needed ! -
I wonder if . . .An M68k could emulate a ULA. You know, like the ZX80 used the cpu for rastering the picture on the screen. This would mean that the people who clone…
An M68k could emulate a ULA.
You know, like ... -
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…
... I see here is that ULA will no longer access video ... . I can't just remove ULA from the circuit because it ... it possible to disable the ULA's video generation functionality (i ... you disconnect the oscillator from ULA?
Also, can someone ... -
A Spectrum that fixes itselfWell, the modulator on my 128K toastrack machine fixed itself. It used to drift horribly within the first half hour or so of power up, but now it's a…
... nice toasty warmth of the ULA, and regular use (I only ... -
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…
...
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Z80 MEMRQ +----+--/\/\/\/---+------>ULA, top 32K RAM
| | |
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 …
... output) or a faulty Ferranti ULA chipset?
Unfortunately spectrum ... from tv.
If ULA is the problem does anyone ... know if there are replacement ULA chips?I know that ferranti ... .uk/T34VG1-USSR-Made-of-ULA-Chip-for-Z80-CPU-ZX ...Fuse for Mac OS X beta releasesA beta version of Fuse for Mac OS X has been released at the dedicated sourceforge project: [url]http://sourceforge.net/projects/fuse-for-macosx/[/u…
... active, as the +2A/+3 ULA applies contention only when MREQ ...Home made SinclairsHi, I mentioned in another thread that I had made a ZX Spectrum out of spare parts. If you'd like to see my efforts, I've set up a simple web page o…
... anything clever like make the ULA circuit out of 74-series ...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…
... are getting excessively hot. The ULA gets a bit toasty, but ... that was normal anyhow. The ULA is a Ferranti 6c001E7.
Spectrum 128K - Needs Your HelpI have a Spectrum 128K (with the external heatsink on the RHS) it is a 1985 Version 6K mainboard, I got it out of the loft the other day and it wont …
... RAM chips (soldered) and the ULA is marked 7K010E5.
Any ...Spectrum +3 disk drive errorsHello!As i am waiting for the ula chips to fix my spectrum 128+ i received another spectrum +3 i bought from ebay. I changed the drive disk belt as …
... i am waiting for the ula chips to fix my spectrum ...Ebay complaintsDoes anybody know how to complain to Ebay about Ebay? They's just scrapped my auction for a ULA chip saying it was an illegal item :lol: So apart f…
... scrapped my auction for a ULA chip saying it was an ...Spectrum Diagnosis: Purple is not my colour!Hi, I thought the self-fault-finding amongst you might appreciate my learning experience this afternoon in fixing my home-made speccy 48K. Yesterda…
... Memory Controller... no seems fine. ULA board... again clean. RAM board ...Harlequin ZX Spectrum Clone now 100% compatible!Hi all! The Harlequin ZX Spectrum clone now shows full timing compatibility with the ZX Spectrum! 8-) Both the ULA IO and memory contentions are fa…
... ! 8-)
Both the ULA IO and memory contentions are ...Anyone knows how ULAs were designed?Hi I just finished reading a very interesting article about [URL="http://arstechnica.com/articles/culture/a-history-of-the-amiga-part-3.ars"]history…
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I'm guessing that ULA is a lot simpler that ...So many questions...I'm a regular reader of this forum and everyday I see so many questions people have. Questions regarding technological decisions made in the past. Qu…
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
... on 128k) cycles after the ULA has pulled the INTREQ low ... cycle after it happens). The ULA needs to fetch the screen ... on the bus when the ULA reads them, not later, especially ... a real machine but unfortunately ULA in my beloved 48k died ...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…
... away from obsolete parts, the ULA is the obvious problem.
ULA and ram I presume..). what ...
