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Double Buffering Artefacts on Real HardwareI have a project that I've played around with for a while and always tested using emulators, either ZX Spin or Spectaculator. It is a 128k game th…
... the "floating bus". This will be 255 when drawing the border and display ... ]
In Timex machines floating bus is 0, if I remember ... don't have I/O contention. -
128K memory bank selection to avoid contention issuesI'm currently developing a game and I'm trying to get my head around the memory contention issues of the various 128K/+2/+2A/+3 spectrum models in or…
... Spectrums do not have the floating bus ("port #FF"). Therefore, you ... with port #7FFD directly and use virtual memory pages instead ... to the results of the contention test outlined above, I can ... what goes into contended memory and what goes into uncontended ... -
Interrupts, 16k Spectrums and snowI'm writing something for the 16k Spectrum and I want to use interrupts. The avilable documentation doesn't seem clear enough for me to figure out ho…
... area will respond with a "floating bus" value (normally 255, but may ... /> So all the restrictions/limitations and affects (including snow) that affect ... /> See Figure 11: Interrupt Acknowledge Timing in http://www.z80.info ... -
Interrupts, 16k Spectrums and snowI'm writing something for the 16k Spectrum and I want to use interrupts. The avilable documentation doesn't seem clear enough for me to figure out ho…
... bottom and top of the screen (and the sides too) where contention isn ... advantadge of using the Sidewize/floating bus teqhnique over IM2 as you ... uncontended portion of the frame and so wring a little bit ... -
Interrupts, 16k Spectrums and snowI'm writing something for the 16k Spectrum and I want to use interrupts. The avilable documentation doesn't seem clear enough for me to figure out ho…
... bottom and top of the screen (and the sides too) where contention isn ... decided to keep the floating bus sync (and I do it on the ... hit at 50hz
2) Floating bus to sync start of drawing ... -
Need help from people with a +2A/+3Started a topic [url="https://www.worldofspectrum.org/forums/discussion/55141/need-help-from-people-with-a-2a-3"]here[/url] to get a broader reach, b…
... I/O contention.[/quote]
Right. Using the floating bus as a ... test program (or, indeed, and emulator) which syncs to an ... . Of course, port contention (and memory contention if such instructions are ... results (using either method). And yet they do.
... -
Need help from people with a +2A/+3Started a topic [url="https://www.worldofspectrum.org/forums/discussion/55141/need-help-from-people-with-a-2a-3"]here[/url] to get a broader reach, b…
... not a hundred percent there timing-wise. This might be prone ... would work on all machines and then just use self-modifying ... value will appear on the floating bus at which T state, but ... code . . . “the wave function collapses” and everything goes haywire. :D -
A Yankee in IraqI'm testing the game on the zx next and it currently hangs right after the game starts no matter what timing regimen and contention pattern is chosen…
... and it's hanging in a loop reading the +3 floating bus through ... 128k mode now with the floating bus reading through 0x40ff. This should ... . Maybe it's extra io contention due to the 0x40ff address. -
Need help from people with a +2A/+3Started a topic [url="https://www.worldofspectrum.org/forums/discussion/55141/need-help-from-people-with-a-2a-3"]here[/url] to get a broader reach, b…
... During idle cycles, the 48K and 128K ULAs will return #FF ... unattached ports, whereas the +2A and +3 ASIC, when memory paging ... info about ULA contention on your page about floating bus is incorrect - ... down the delays for each and every instruction, the guide ... -
Need help from people with a +2A/+3Started a topic [url="https://www.worldofspectrum.org/forums/discussion/55141/need-help-from-people-with-a-2a-3"]here[/url] to get a broader reach, b…
... br /> 48K 128K +3 ULA bus
-----------------------------
14338 ... doubt you could really read floating bus from even ports.
... but specifying 4 T contention and 4 T free cycles is ... think it's stock floating bus test just modified to ... -
Need help from people with a +2A/+3Started a topic [url="https://www.worldofspectrum.org/forums/discussion/55141/need-help-from-people-with-a-2a-3"]here[/url] to get a broader reach, b…
... more, but specifying 4 T contention and 4 T free cycles is ... colorful attributes at the top and bunch of numbers on rest ... . I think it's stock floating bus test just modified to use ... -
Delay routineAs some people are aware, I have recently starting writing a [url=http://fuse-emulator.svn.sourceforge.net/viewvc/fuse-emulator/trunk/fusetest/]autom…
... in programs which were testing contention and timing details, it was super important ... they are not affected by bus/contention under any circumstances. -
ANN: Spectaculator 2.5 available for downloadHi. I've just released a new version of Spectaculator, available from [url="http://www.spectaculator.com/"]http://www.spectaculator.com/[/url]. Hopef…
... /> - 'View Cassette recorder' and 'Reset the Spectrum' are available ... - Online help revised and converted from WinHelp to HTML ... - Floating bus emulation as per Ramsoft technical docs (Sidewize and Richochet< ... e.g. Shock Megademo and
Overscan demos).
Problems with games on +2AHi! I have a +2A now and have problems running some games on it. I tought the resistor fix (to give it some kind of "floating bus" as the original 4…
... I have a +2A now and have problems running some games ... kind of "floating bus" as the original 48k and 128k have) and the roms ... Duet, Arkanoid 1 (both 48 and 128k) etc. started working properly ... just starts acting all weirdly and crashes or graphics get corrupt ...Hardware GuideI was thinking this might make a good sticky... [b]Service Manuals[/b] [URL="ftp://ftp.worldofspectrum.org/pub/sinclair/technical-docs/ZXSpectrum48K…
... , Schematics, Manuals, including Peripherals/Interfaces and Other Computer Models, can be ... very neat Spectrum fixes and Hardware mods and Interfaces by Sami Vehmaa ... /floatingbus.html"]The Floating Bus Explained[/URL] -Info about the Floating Bus and the 'snow ...Bubble Bus SoftwareI'm wondering why Infoseek has this down as "Bubblebus Software", when it's "Bubble Bus Software" on cassettes & adverts. Or, to be even more accurat…
... Software", when it's "Bubble Bus Software" on cassettes & ... "bubble bus" or "bubble bus software" in titles, and "Bubble Bus Software" ... />
The other Bubble Bus MIA, Curse of the Crown ... sale, probably because Bubble Bus ceased trading during that year ...Sinclairean A3[B]Sinclairean[/B], a new ZX Spectrum emulator written in machine code for x86-compatible, OpenGL-capable computers. Features: [LIST] [*]Fast machin…
...
[*]Smooth screen updates and 50 Hz conversion
[/ ... not emulated yet
[*]Floating bus not emulated yet
[*] ... from explorer) to load and execute it. Without arguments, ... [LIST]
[*]HUD-like UI and debugger/monitor
[*]Windowed mode ...JSpeccy: New emulatorHi there, Jos? Luis S?nchez (zx81 at ono dot com) has developed a new ZX Spectrum emulator in Java, with a very accurate Z80 emulation. The message …
... Z80, including the undocumented instructions and flags
- Accurate execution ... Demo)
- Floating bus emulation (Arkanoid, Sidewize)
- Speaker and MIC emulation (Cobra ... /> - Multi-language support (English and Spanish available now).
IM2 Loading on +3EHi there Speccy Guru's, As some of you know, I've spent a while building the ultimate image for +3e, it's currently at 6000+games and demos and i've…
... 's currently at 6000+games and demos and i've been converting ... "simple" single load demos and megademos and moved onto the IM2 loading ... disks work great on Spectaculator and Spin, I tried today to ... 's not due to the floating bus, maybe the real hardware changes ...Tricks with IN 31It's generally considered unwise to use a Kempston joystick's fire button to start a game, because the floating bus effect can make arbitrary data ap…
... start a game, because the floating bus effect can make arbitrary data ... the Kempston interface is disconnected, and I read IN 31 while ... /> If the interface is connected, and I read IN 31, can ...48K Speccy Repair Log.Some people may know my love for writing up my repairs of arcade PCBs on various forums so thought I would do the same for this little fella. Had th…
... case and the base spent the last 3 years at least floating ... ROM was ok, and that the databus and address bus were fine, or ... at least the address bus up ... RAM is located between 8000 and FFFF and the short ram test ...Shadow ROM partial decoding not implemented in emulatorsOr at least, not implemented in Spectaculator, and it seems that not in Fuse too. [URL="http://www.speccy.org/foro/viewtopic.php?f=8&t=408&start=53"…
... least, not implemented in Spectaculator, and it seems that not in ... from the main ROM, not floating bus (ULA/FFh), of a mirror ... the same test using Spectaculator and it behaved the same as ... partially decodes the shadow ROM and therefore, the last 8192 bytes ...Enable 128kB paging in emulatorFrom Zx Spectrum documentation ([url]http://www.worldofspectrum.org/faq/reference/128kreference.htm[/url]) [CODE][SIZE="1"]When memory is being pag…
... , interrupts should be disabled and the stack should be in ... 0x7ffd produces no special results: floating bus values will be returned as ... affect the memory between 0x4000 and 0x7fff, which is always ... memory paging will be disabled and further output to this port ...Tricky ZX RepairHello guys, This time I put my hands on a very nice Issue 3 16K, upgraded to 48K. To bertter explain "nice", it is absolutely mint, not a scratch on…
... the plastics, edge connector new and shiny... really 10 out ... within limits, no blown TR4 and/or associated paraphernalia. Current ... I then removed all 4532 and associated decoding chips (nice to ... to switch on the scope. Floating bus seems to behave okay. DMM ...****ing Awesome Spectrum Engine (FASE)This is a new engine (sprites, tiles, map) for all ZX Spectrum machines. The engine set ups a runtime enviroment that leave between 24K and 30K byt…
... enviroment that leave between 24K and 30K bytes free from $ ... INIT to initialize the engine and FRAME, that put all the ... diferent implementation for each machine (floating bus in 48K, shadow screen in ... thanks to Hikaru and mixing with the 128K and generic engine ...Port $28FF. Why 28?Testing floating bus behaviour for ZXUno, I've found that both Cobra and Arkanoid use this specific 16-bit port: $28FF. What is so special about putt…
Testing floating bus behaviour for ZXUno, I've found that both Cobra and Arkanoid use this specific 16-bit port: $28FF. What is so special about putting the value $28 in A15-A8 during a read to $FF?
Thank you very much in advance! :)New stable version ZEsarUX-4.2Hi everyone! I have uploaded a new stable version of ZEsarUX emulator, version 4.2. You can download it from: https://sourceforge.net/projec…
... bug reading ports 2ffd and 3ffd and crashes running +2A/+3 ... /> Fixed enabling some memory and debug interfaces, so you ... is shown
Improved floating bus value
Updated Z88 OZ ...
Some other minor bugfixes and improvements
Need help from people with a +2A/+3Started a topic [url="https://www.worldofspectrum.org/forums/discussion/55141/need-help-from-people-with-a-2a-3"]here[/url] to get a broader reach, b…
... of the elusive floating bus on these machines, and no emulator ( ... 4093) and see if I can fetch a bus value ... , Retro Virtual Machine, and zesarUX alike seem to return ... different (and from my point of ... do this anyway), and skip ULA/bus polling on a ...New emulator - Spectramine v.1.0b releasedI post the first release of my Spectramine emulator, with minimal functionality, for public testing of emulation quality and compatibility with games…
... the emulator through context menu and shortcuts.
and ULAplus emulation, Spectramine limitedly supports ... -DOS (.trd, .scl and hobeta files), and +3DOS (.dsk files), ... him for that!). Also, floating bus of +2A/+3 is ...
