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'Interesting' Issue 2 modSo I've been lurking on this forum for a while and I've got to the point where I want to see if I can repair a speccy.. so I bought me a 'broken' one…
[QUOTE=1024MAK;795153]With no ULA, there is no video signal ... br />
With a working ULA, PAL colour encoder chip, working ... but the data that the ULA reads will either be that ... ! The display switches between vertical stripes of various colours and thickness ... -
A redesigned version of Winston's diagnostic board[U][B]A redesigned version of Winston's diagnostic board[/B][/U] This is a continuation of a project that started in a hijacked thread [URL="http://…
... ) and a rudimentary ULA test.
Flash tool's been updated ... with code to detect flash type, I'll be able ... -
A redesigned version of Winston's diagnostic board[U][B]A redesigned version of Winston's diagnostic board[/B][/U] This is a continuation of a project that started in a hijacked thread [URL="http://…
... ) and a rudimentary ULA test.
Flash tool's been updated ... with code to detect flash type, I'll be able ... -
Please explain Spectrum FPGA-clones to meI've been using the great ZXDS-emulator on the DS XL so far, which is great. But I kinda missed toying around with hardware. I've tried bidding on a …
... code, embedded in ROM or flash.
The configuration for ... an FPGA is held in flash, bit it isn't program ... lot like a re-configurable ULA. :)
A CPLD or FPGA ... no more firmware than the ULA metallization photographic masks is ;) -
Please explain Spectrum FPGA-clones to meI've been using the great ZXDS-emulator on the DS XL so far, which is great. But I kinda missed toying around with hardware. I've tried bidding on a …
... emulator then? After all, the ULA which has been developed (programmed ... about EEPROM / E?PROM and Flash ROM? Are these wrong because ... / FPGA / EEPROM / E?PROM and Flash ROM? Is using the combination ... -
Weird symptom number 2...I got a new keyboard membrane for my Spectrum+ plugged it in and low and behold the weird left to right printing of the copyright message disappeared…
... at the top centre (the ULA input display block) isn't ... one?
That means the ULA is getting logical low on ... had a brief flash of yellow and the ULA blob appeared, exactly ... -
Weird symptom number 2...I got a new keyboard membrane for my Spectrum+ plugged it in and low and behold the weird left to right printing of the copyright message disappeared…
... had a brief flash of yellow and the ULA blob appeared, exactly ... -
Please explain Spectrum FPGA-clones to meI've been using the great ZXDS-emulator on the DS XL so far, which is great. But I kinda missed toying around with hardware. I've tried bidding on a …
... Spectrum that, with a quick flash of a ROM, could be ... of these have a Ferranti ULA in them, they use an ... -
Please explain Spectrum FPGA-clones to meI've been using the great ZXDS-emulator on the DS XL so far, which is great. But I kinda missed toying around with hardware. I've tried bidding on a …
... is no difference between a ULA implementation and an FPGA ... because that machine saw several ULA revisions, several PCB revisions and ... Spectrum that, with a quick flash of a ROM, could be ... technology :) Whereas the Spectrum ULA would have required a fab ... -
Issue 2 Spectrum - Black screenHi I have an issue 2 spectrum which I'm having some issues with. I bought it on ebay so have no idea of the history or how it came to be broken. Whe…
... you'd have white vertical stripes.
If you have ... and upper), then check the ULA and the ROM. It may ... -
Detecting flash mode inversionsIs is possible to detect with certainty when flashing characters change from normal to inverted and vice-versa?
... an idea: forget about hardware flash. Do the flashing via software ... to find which state is ULA in :) Can't we force ... ula to make a mistake and ... -
Detecting flash mode inversionsIs is possible to detect with certainty when flashing characters change from normal to inverted and vice-versa?
[QUOTE=Basher;802628]Could you monitor the floating bus to find the point where the flash switches over then count frames from then on?[/QUOTE]
floating bus behaviour is well examined, I don't think ula wil give up this information easily. -
Detecting flash mode inversionsIs is possible to detect with certainty when flashing characters change from normal to inverted and vice-versa?
... examined, I don't think ula wil give up this information ... the ULA so it hasn't been inverted by the flash logic ... -
Detecting flash mode inversionsIs is possible to detect with certainty when flashing characters change from normal to inverted and vice-versa?
... cycle takes 32 frames. ula switches color every 16 frames ... />
[code]
5 FLASH 0: CLS : FLASH 1
10 LET ... emulators use different timings for flash effect.
2. there ... correlation between frames counter and ula internal counter.
3. ... -
Detecting flash mode inversionsIs is possible to detect with certainty when flashing characters change from normal to inverted and vice-versa?
... emulators use different timings for flash effect.
2. there is ... correlation between frames counter and ula internal counter.
3. my ... the frames counter and the flash counter actually increment the same ... -
Issue with Issue Two[img]https://dl.dropboxusercontent.com/u/25300140/Spectrum/Edited_ImageEasyImageEditor_20141111_84.jpg[/img] I'm working on an Issue Two that was sh…
Ok, it was the ULA. I swapped them over from ... black screen with thin vertical stripes on mine.
Probably ... should've checked the ULA straight away as I initially ... -
Detecting flash mode inversionsIs is possible to detect with certainty when flashing characters change from normal to inverted and vice-versa?
... with the flash, it's entirely internal to the ULA and not ... -
Detecting flash mode inversionsIs is possible to detect with certainty when flashing characters change from normal to inverted and vice-versa?
... is switched on? All squares FLASH in synch, regardless of when ... the FLASH attribute was set for any ... particular square, so the ULA must be referencing an independent ... the display is in the ULA's FLASH cycle.
Although ... -
Detecting flash mode inversionsIs is possible to detect with certainty when flashing characters change from normal to inverted and vice-versa?
... ;803174]Isn't the FLASH change always going to ... switched on? All squares FLASH in synch, regardless of ... when the FLASH attribute was set for any ... the ULA and inverts any attributes with the flash bit ... the state of the flash from code without a ... -
Detecting flash mode inversionsIs is possible to detect with certainty when flashing characters change from normal to inverted and vice-versa?
... it doesn't reset the ULA's FLASH cycle after a hard ... 16th FRAMES increment and setting FLASH at some point offset from ... PRINT FLASH evaluates to "ON" and this coincides with the ULA starting ... more enlightening, though. Some steps FLASH is on, sometimes it's ... -
Detecting flash mode inversionsIs is possible to detect with certainty when flashing characters change from normal to inverted and vice-versa?
... Bunny;803182]Some steps FLASH is on, sometimes it's ... update screen every frame, using FLASH 1 during first 16 frames ... correct, FLASH 1 will coincide exactly with frames where ULA doesn't ... invert attributes, thus nothing would flash on ... -
What is the Sinclair ZX Spectrum Vega and what does it mean?Just stumbled upon this Indiegogo page following a tweet from SpeccyNews [url]https://www.indiegogo.com/projects/sinclair-zx-spectrum-vega[/url] it…
... that boots straight off the flash for something like this? You ... /> Writing a z80 core and ULA emulation from scratch should only ... -
Which emulators support ULA+Tried ZX Spin 7.0, but its unstable. Tried to drag and drop .scr files onto it, but it comes out all wrong. Don't understand the TAP file that's sp…
... is designate FLASH and BRIGHT values within a program and ULA+ does ... has been loaded on a ULA+ Spectrum?
Is there ... -
48k noise problem..Hi guys, I need some hardware advice with my old 48k. The machine is VERY noisy - I've fixed the video noise by performing the 'composite' mod, but …
... speaker and the boarder should flash between two different colours. One ... flashing border becomes blue/yellow stripes.
I hope this ... -
What influence the number of stripes during initialization?Hi for All! After some adventures, with other rare old computers I'm back here to my favourite forum. :) Recently I got some ISSUE 2 boards from Ben…
... with 5C102E ULA and NEC RAM that shows four stripes when held ... -
128k toast rack diagnosisHi - I recently won a 128K toast rack, and have got a Retroleum smart card. I've tried a couple of games and all seems fine...-ish.<div><br></div><di…
... />
Have you tried the ULA tests (accessed by holding U ... ) - this should produce uniform green stripes across the entire screen if ... -
External Z80 CPUHi Looking for some advice if possible. Many years ago I had a plug-in board for a Spectrum 48k which had a couple of switches, a z80 CPU, and a S…
... info/book/"]The ZX Spectrum ULA[/url] Book is recommended ... 27C256 EPROM (or a 28C256 flash) chip. Program the normal ZX ... to program the EPROM or flash chip. If needed use ... line on the EPROM or flash chip (EPROM pin 27 ... pin 1 on a 28C256 flash) to a 10k pull- ... -
48k not startingHi team, I have 2 48k's, one works (Issue 4s), one doesn't (Issue 4a). The non-working one appears to start, but not finish the RAM test. The pape…
... ROM (or EPROM/EEPROM/E2PROM/flash ROM). This can then do ... on what the CPU and ULA are doing.
[b ... -
Vega ARM SOC?I read that the core of the new Vega was an ARM SOC. I thought it would have been an FPGA. But it seems it's an ARM running an emulator. Anyone kn…
... ARM is doing the Z80 / ULA emulation along with creating both ... internal registers, (presumably) plenty of flash memory + RAM included, and much ... -program the ARM cpu. And flash memory! (if included, that is ... -
Jiiira's Sparrow LITEHi All, Just for info .. :) big eprom, cheap 32KB ram and etc. i don't know specification .. :) https://youtu.be/NbI7E1aebrM modern speccy .. …
... br />
* Original Sinclair ULA. :( Design already includes a small ... Harlequin logic in there? Original ULA probably means: highly compatible. ... in the case of Spectrum ULA's, probably sooner than ... in particular).
* Big flash ROM (2Mbit = 256 KB). ...
