World of Spectrum
  • Categories
  • Discussions
  • FAQ
  • Sign In
Home › Search
Title Search
@title beer Word 'beer' in title
User Search
  • @user admin Only posts by Admin
Text Search
  • @body beer Word 'beer' in the text
Phrase Search
"Hello World" Exact phrase match
Exclude Terms
  • car -red Search cars that are not red
"Or" Searches
  • honda | bmw 'honda' or 'bmw' results
Multi-Field
@(title,body) hello Both contain 'hello'
WildCard
  • hond* civ* Match all with an astrix
Combination
  • @title bmw @user admin
See more supported syntax examples
Search Again :: Adv Search 1000 results in 0.008s
<1…16171819202122…34>
  • Developing ZX Spectrum using 8 chipsHello. Sorry, my english is not perfect. I am developing new realising of ZX Spectrum. There are 8 chips in my sch. Central processor and video proce…

    ... won't be normal speed, timing accurate or anything.[/QUOTE]
    timing compatible. Emulating the Z80, I ... of a problem. Emulating the ULA will be much harder; if ... the CPLD implementation of the ULA, and use that for the ...
    Winston Winston September 2010 Hardware
  • ZX ULA Book releaseThe book is complete and with the printer. Once the proof copy is back and checked, and assuming no changes are required, I'll start shipping all you…

    ... cover. Very enlightening, especially the ULA bugs and work arounds, that ... lookup the Z80 memory access timing picture elsewhere. :)

    Seriously ...
    Patrik Rak Patrik Rak September 2010 Sinclair Miscellaneous
  • zx spectrum ULAis the ULA in the 16K the same as in the 48K could you take the 16K ULA and place it in a 48K I ask this because i have a speccy thats dogy with th…

    ... =Robin;482581]is the ULA in the 16K the same ... could you take the 16K ULA and place it in a ... />
    Depends on the ULA version. There are few which ... one which changed the timing of one video sync ... .co.uk/ZX-Spectrum-ULA-Design-Microcomputer/dp/0956507107"] ...
    Patrik Rak Patrik Rak October 2010 Hardware
  • Can someone identify thisSorry if it's something extremely obvious but this is the first time I've had my hands on a Spectrum in about 20 years (thanks eBay) and although som…

    ... older version ULA + a small factory mod to correct some timing/logic ... picture (under the tape, between ULA & Z80). Maybe issue 2 ...
    RetroTechie RetroTechie October 2010 Hardware
  • DMA interface for ZX Spectrum[url]http://velesoft.speccy.cz/data-gear.htm[/url] This is internal DATA-GEAR interface for any 8-bit computer with Z80CPU. Use Direct Memory Access…

    ... refresh and certainly no video ula ram contention to contend with mind ... for ntsc machines!
    pity ula+ not sam compatible and still ...
    Roger Jowett Roger Jowett October 2010 Hardware
  • Spectaculator... is it worth the money?Hi Folks, This is a genuine request for feedback. I have used the demo version of Spectaculator and it seems a very good Spectrum emulator. Lots o…

    ... is the comments about the timing being off compared to SPIN ... i spoke about spin, although timing is fairly accurate many of ... speed. Maybe its an inaccurate contention issue, maybe IY or IX ...
    nuggetreggae nuggetreggae December 2010 Emulators
  • Can a ZX81 be upgraded to a Spectrum?No, I don't want to do this, and I agree that to do so (even if I could) would be a waste of time. The question is, is it possible though? The upgrad…

    ... Chris Smith's ULA book taught me was ... the Spectrum is the ULA whereas I've always ... will be the ULA which drives the screen, timing, interrupts etc ... . and once you have replaced a Zx81 ULA ... a Spectrum if the ULA was replaced and various ...
    BloodBaz BloodBaz December 2010 Hardware
  • Can a ZX81 be upgraded to a Spectrum?No, I don't want to do this, and I agree that to do so (even if I could) would be a waste of time. The question is, is it possible though? The upgrad…

    ... screen. Or mimic a super ULA, when that denomination suits you ... , like the ZX81 guys used timing peculiarities of ZX81 to transfer ...
    roko roko December 2010 Hardware
  • repaired a 48K, yay :)I just managed to repair one 48K. After socketing all eight lower RAM chips (hard work!) and replacing few of them, it showed the familiar "Sinclair …

    ... relationship to the ULA and the requirements for video timing, etc.
    ULA. The upper RAM connects directly ... book [I]The ZX Spectrum ULA[/I] useful.

    Nb ...
    RST#08 RST#08 January 2011 Hardware
  • Recent talk of developing new SpectrumsHi all, I can see from a few threads on here that some Wossers like Vasil and Aien 8 are interested in developing more powerful Spectrums or improvi…

    ...
    Richard Altwasser designed the ULA (being the Spectrum expert), Ferranti ... were the ULA experts) and any routing or timing issues were ... test vectors passed on each ULA die produced, discarding those ... that failed. Whether the ULA worked as expected in ...
    csmith csmith January 2011 Hardware
  • Speccy 128 Shadow screen.How much is the shadow screen used in 128k commercial software? I ask because I am looking at putting 128k of memory in the 48k setup I have been bu…

    ... dedicated to the 128K ULA in the ULA Versions chapter, though it ... only explains the reason behind the timing ... superficial mods, the 128K ULA is identical to the 48K ... the false impression that the ULA is involved.

    ...
    csmith csmith January 2011 Hardware
  • Speccy 128 Shadow screen.How much is the shadow screen used in 128k commercial software? I ask because I am looking at putting 128k of memory in the 48k setup I have been bu…

    ... dedicated to the 128K ULA in the ULA Versions chapter, though it ... only explains the reason behind the timing ... superficial mods, the 128K ULA is identical to the 48K ... the false impression that the ULA is involved.
    [/QUOTE]< ...
    spodula spodula January 2011 Hardware
  • How the spectrum generates the video from ramHi everyon, I know that most people here allready know this but i think i found out how the spectrum acctually dispalys stuff and why the LD x, (HL)…

    I think the ULA reads the video ram in ... is the source of the contention delays when reading or writing ... spectrum.

    Basically the ULA is the master of the ...
    wozname wozname January 2011 Hardware
  • How the spectrum generates the video from ramHi everyon, I know that most people here allready know this but i think i found out how the spectrum acctually dispalys stuff and why the LD x, (HL)…

    The cpu and ula cannot access the display ... are time sensitive. The ula has to pause the cpu ... conflict and this is called contention. By having a physically ... 32k without any worries of contention. That's why the ... fast and have the ula or display device access ...
    Alcoholics Anonymous Alcoholics Anonymous January 2011 Hardware
  • How the spectrum generates the video from ramHi everyon, I know that most people here allready know this but i think i found out how the spectrum acctually dispalys stuff and why the LD x, (HL)…

    ... line.[/QUOTE]
    AFAIK the ULA only makes the Z80 wait ... .

    [QUOTE]Basically the ULA is the master of the ... reference for all things Spectrum ULA. Tip: you might also want ... of details about composite video timing (and generating black & white ...
    RetroTechie RetroTechie January 2011 Hardware
  • contended memory...so memory contention on the toastrack and the grey +2 is in the wrong place compared to the documentation, yet the +2a/b and +3 it is in the correct …

    So the question for games not running properly is not that the CPU contention timing is different, but that contention is applied differently to memory banks on the toastrack/+2 and the +2a/b/3.

    Which runs the most games?
    csmith csmith January 2011 Hardware
  • contended memory...so memory contention on the toastrack and the grey +2 is in the wrong place compared to the documentation, yet the +2a/b and +3 it is in the correct …

    ... that the CPU contention timing is different, but that contention is applied differently ...
    BiNMaN BiNMaN January 2011 Hardware
  • contended memory...so memory contention on the toastrack and the grey +2 is in the wrong place compared to the documentation, yet the +2a/b and +3 it is in the correct …

    ... that the CPU contention timing is different, but that contention is applied differently ... /+2B, or written assuming the contention in the manual will work ...
    guesser guesser January 2011 Hardware
  • Contention: LDI vs LD (ss), rAccording c.s.s. FAQ: instruction LD (ss),r breakdowns as pc:4,[b]ss:3[/b] and LDI as pc:4,pc+1:4,hl:3,[b]de:3,de:1 x 2[/b] can anyone explain why …

    ... ]

    See csmith's ULA book for full details, but ... 0,0 bit of the contention pattern.
    Philip Kendall Philip Kendall February 2011 Development
  • Smooth (vertical) scrolling on ZX SpectrumI was just thinking about this. You know, you have systems like Atari 2600 or Sega SG-1000 that have no hardware scroll, but they have games that sti…

    ... to do the tricks within ULA display time.[/QUOTE]


    Here's the secret....ULA tricks don't really matter ... don't do any fancy timing or measuring (joefish can confirm ...
    Turkwel Turkwel February 2011 Games
  • Smooth (vertical) scrolling on ZX SpectrumI was just thinking about this. You know, you have systems like Atari 2600 or Sega SG-1000 that have no hardware scroll, but they have games that sti…

    ... ;513486]Here's the secret....ULA tricks don't really matter ... don't do any fancy timing or measuring (joefish can confirm ...
    jonathan jonathan February 2011 Games
  • Is this the infamous Dead CockroachCan anyone help me. I have an issue two spectrum that I want to list on ebay, but I want to know if this has the dead cockroach ULA fix. I would have…

    ... there was a timing error in the original ULA design and this ... cockroach" - due to timing error in the ULA chip it was necessary ...
    flashbackgames flashbackgames March 2011 Hardware
  • contended memory...so memory contention on the toastrack and the grey +2 is in the wrong place compared to the documentation, yet the +2a/b and +3 it is in the correct …

    ... will have less than perfect timing if run on the +2A ... probably need to support both contention models and make them switchable ...
    chev chev April 2011 Hardware
  • 50Hurts - Full-screen 50Hz 1-pixel scrolling on a 128K Speccy50Hurts - Full-screen 50Hz 1-pixel horizontal scrolling on a 128K Speccy. Graphics are an obvious nod to Joffa, whose games and banter were a big ins…

    ... the +2A (no I/O contention). But basically I'd avoid ... joystick/keyboard read during the timing critical stuff.
    chev chev April 2011 Development
  • 50Hurts - Full-screen 50Hz 1-pixel scrolling on a 128K Speccy50Hurts - Full-screen 50Hz 1-pixel horizontal scrolling on a 128K Speccy. Graphics are an obvious nod to Joffa, whose games and banter were a big ins…

    ... continue to do that! contention is evil, ULA is evil!

    Ketmar Ketmar April 2011 Development
  • Speccybob PCB layoutSorry to start yet another Speccybob thread, but I can't seem to find out if anyone has tested Mike Wynne's PCB layouts. I have amassed all of the co…

    ... achievement that speccybob was, the timing compatibility with a real Speccy ... Harlequin is the only 100% timing correct "clone".

    If ... the proud owner of your ULA book. I considered breadboarding your ...
    amotyka amotyka May 2011 Hardware
  • 48k dots appear but not with CUB monitorToday I tried out an issue 3 and an Issue 2 with the CUB monitor, to my surprise they both worked flawlessly, now before when I tried them on any oth…

    ... -prototype-or-the-importance-of-ula-cooling[/url][/QUOTE]
    < ... + boards and their ula's had a timing fix which was documented ... difference. It also suggests the timing was a bit marginal previously ... remember this referenced in the ULA book)

    [B] ...
    spodula spodula June 2011 Hardware
  • 128K Contention - How to get it right?With my recent hardware hackery, I've built a 128K (toastrack) clone. I can't quite get the contention right though. What I'm lack is a clear descri…

    ... fusetest differentiate between machines through timing?[/quote]

    It doesn ... known bug in the 128K ULA.

    The 0xbffd test ...
    Philip Kendall Philip Kendall July 2011 Hardware
  • 128K Contention - How to get it right?With my recent hardware hackery, I've built a 128K (toastrack) clone. I can't quite get the contention right though. What I'm lack is a clear descri…

    ... as I (supposedly) corrected the contention handling for IO where a ... understood the circumstances when IO contention is applied to the 0x7ffd ... known bug in the 128K ULA.[/quote]

    For my ...
    csmith csmith July 2011 Hardware
  • 128K Contention - How to get it right?With my recent hardware hackery, I've built a 128K (toastrack) clone. I can't quite get the contention right though. What I'm lack is a clear descri…

    ... Chris's book about ULA the IO contention shouldn't depend on ...
    vranik vranik July 2011 Hardware
<1…16171819202122…34>

Latest Posts

  • Happy 40th Birthday to the Amstrad CPC464!
    dmsmith on 6:19PM
  • Another Birthday! The Game Boy Is 35!
    dm_boozefreek on 6:17PM
  • I bought an accoustic guitar. How do you play it?
    Maroc's Other Projection on 6:04PM
  • I am currently watching.....
    Antiriad2097 on 5:05PM
  • European Software Titles with an English version
    harriusherbartio on 12:06PM
  • How Do You Categorize Your Speccy Software and Games?
    harriusherbartio on 11:21AM
  • Fixed Speccy Software. And which games remained unfixed?
    harriusherbartio on 11:01AM
  • New video about S-video modification on Issue two 48K Spectrum.
    Renegade on April 21
  • Elusive Strategy Games done by the Smaller or less Prolific Software Houses.
    harriusherbartio on April 21
  • 1992 Spectrum Software
    harriusherbartio on April 21

HitBox

Word Docs Hits
contention 1.4K 2.4K
ula 7.3K 13K
timing 3.3K 4.1K

Related Threads

  • ULA......Woooooo and ULA 160??'ello all from down under !<br /> <br /> they don't know the speccy well this way it seems, <br /> <br /> anyways, picked up my brand new astra yeste…
  • Contention and floating bus timingHello,<br /> <br /> 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.…
  • Serching for ZX printer ULA and ZX interface I ULAIs there anyone having any spares. In both cases, I swapped ULA's from working equipment which fixed things, so I'm 100% sure it's the ULA that is ca…
  • Where: ZX Printer ULA's and ZX interface I ULA'sIs there any source left for these ULA's? Alot of tings can be replaced, like the ZTX transistors and occasionally you can come accross a normal ZX S…
  • New test for finding missing +2A/+3 ULA timing detailsHello,<br /> <br /> having added the +2A/+3 emulation recently, I want to make sure I got the ULA timing 100% right. We know when the contention patt…
  • 5C Horizontal timing vs 6C horizontal timing.Hi all,<br /> <br /> Just considering the timing difference in the video signal between the 5C and the 6C where the 6C ULA seems to have 50% longer…
  • WANTED: 128k+ or 128k +2(early grey mod.) ULA chipHello,<br /> Attempting to repair my 128k+ speccy.<br /> Needs a ULA(IC1)chip from either a 128k+ or an early +2 will work also.<br /> If anyone has …
  • TimingHey All,<br /> <br /> Is their away of obtaining timing information on ZX128k other than addresses 23672-&gt;23674. Basically I would like to identi…
  • ULA schematicsHi everyone.<br /> <br /> Some while ago I remember getting hold of some circuit schematics of the innards of the Speccy 48K ULA. Sadly I've since lo…
  • ULA?Just curious, what does ULA stand for - I'm guessing Ultra Large (Gate) Array?

Related Searches

  • 2a timing
  • 3b ula
  • issue 3b ula
  • harlequin modified ula
  • ula model 2
  • ula
  • zx 2 ula
  • zx 2 ula interchange
  • zx 2 ula swap
  • grey 2 ula swap
  • ula 128
  • ula replacement
  • 2b dead ula
  • black 2 dead ula
  • slam ula
  • contention timing
  • contetion timing ula
  • contention ula
  • 128 ula timing test
  • contention and floating bus timing

Copyright © 2024 World of Spectrum