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Detect if program was loaded from tape or microdriveHow (if at all) can a BASIC program detect if it was loaded from tape or microdrive? This can be helpful to then load the screen or more machine code…
... all) can a BASIC program detect if it was loaded from ... -
Memory Map/ContentionHi I'm new to speccy coding (well I did some z80 coding a few years back - like 20yrs ago :) ), and I'd like to get back into writing some scrolling…
... a correct map for memory contention?
Address Size Area ... -
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…
... .s faq describing I/O contention.
The 48k ... to lead to the following contention patterns:
High ... /> in 40 - 7F? | Low bit | Contention pattern
------------+---------+-------------------
No | Reset ... -
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…
... playing a bit with memory contention and floating bus stuff in ... sense it starts applying the contention a few cycles earlier, namely ... -
+3 how to detect if a file exist ?Need help. I am making a generic menu to my compilations over the spectrum +3. Exist some way programatically to detect if some file exists on the d…
... /> Exist some way programatically to detect if some file exists on ... a 'cat' but, how to detect if exist programatically sounds hard ... -
detect deleteHi everone How can you detect that the caps + 0 (delete) is selected. Im making a word program for fun, but i need to be able to delete characters..…
Hi everone
How can you detect that the caps + 0 (delete) is selected. Im making a word program for fun, but i need to be able to delete characters..
Thanks -
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…
... 0x7ffd, 0xbffd and 0x3ffd port contention behaviour.
... However, I find that contention is applied too often ... /> To correct the excessive contention, I replicated ULA14 and ULA15 ... someone describe accurately the contention behaviour for the 128K ... -
What is the best way to detect CAPS LOCK?Hi Folks, Not sure what the correct behaviour is here as I do not have access to a real Spectrum. Under BASin, when you press CAPS LOCK on the PC k…
... is the best way to detect CAPS LOCK from BASIC? When ... -
BIT b,(ii+n) contentionThe documentation says that BIT b,(ii+n) has this contention pattern: pc+1:4,pc+2:3,pc+3:3,pc+3:1 x 2,ii+n:3,ii+n:1 See [url]http://scratchpad.wiki…
... b,(ii+n) has this contention pattern:
pc+1 ... Tstate.
So the contention pattern should be:
Revisiting Spectrum CPU clock regenerationWarning: This post will be a bit nerdy :-) Some time ago, I experimented with phase locked loop circuits as a possible way to regenerate the Spectru…
... - that's to say, detect when our regenerated 3.5MHz ... when we're able to detect in which direction the ... counting Spectrum clock cycles since contention started, and one counting ... regenerated clock cycles since contention started.
[img ...How do I detect if key 'H' is pressed in machine code?How do I detect that the key has been pressed? I have been using the IN 239 command for keys 6-0, but dont know how to detech 'H'...
How do I detect that the key has been pressed?
I have been using the IN 239 command for keys 6-0, but dont know how to detech 'H'...Understanding contentionI'm trying to understand contention and its implications when some "weird" bus cycles (such as I/O cycles with I/O addresses in the contended memory …
I'm trying to understand contention and its implications when some ... both memory and I/O contention. Memory contention causes T1 to be ... ?
Also: memory contention makes T1 to be enlarged ... for instance, to avoid memory contention) that begins at the ...Question of contentionI'm not desperate to go digging through technical descriptions in depth, but one thing bugs me about the Speccy's video contention model - and that's…
... about the Speccy's video contention model - and that's the ... /> And then there's the contention pattern where the memory is ... 16, so that means the contention pattern covers a run of ...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…
... my head around the memory contention issues of the various 128K ... what is the cause of contention for banks 1,3,4 ... downs due to this apparent contention issue.Memory Contention: A Hypothetical Fix?I have just had this crazy thought: If one were to wire an additional memory chip, say a 6264 8Kx8 SRAM, in parallel with the main memory so that it …
... reduce the effect of memory contention considerably. Possibly with the addition ...Other than using attributes what other ways to detect collisions, when using char based movement?So I'm slowly working out the bits and pieces to write a game completely in assembly. I've been using attributes when writing in BASIC to detect whet…
... when writing in BASIC to detect whether and object hits another ...Writing own emulator: Contention questionsHi! (I don't know if this message should be here or in Hardware) I'm trying to write my own emulator just for the sake of it, and I'm having pr…
... having problems understanding the memory contention in 48k, in instructions like ... is being used there for contention.
Thanks ...A few questions regarding EmuZwinI had posted this in the development forum and then remembered there was an emulators forum, so apologies for the repetition. 1. I have been trying …
... for the details on memory contention.
[quote]
4 ... implementation. I use this to detect which part of the screen ...RealXThis may be a dumb question but will RealX ever get released?
... =Woody]Dunny likes to call contention based on the IR register ... does), which can possibly cause contention [b]later[/b], but certainly ... and it doesn't apply contention to take precedence as usual ... . This caused the CPLD to detect the INT duration sometimes as ...RealXThis may be a dumb question but will RealX ever get released?
... there is no trace of contention applied during T3-T4 of ... does), which can possibly cause contention later, but certainly not during ... , thought I'd said the contention was outside of fetch cycles ... /> This caused the CPLD to detect the INT duration sometimes as ...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…
... = 0x4000 - 0x7fff AND MREQ high contention selection?[/QUOTE]
Simple ... 3 ULA, which applies less contention than the 48K ULA (specifically ... uses the ~MREQ high to detect T1 (and thus gets ... proper ~MREQ low to detect the actual memory accesses.
Benchmark timeWell, the BASIC benchmark posted in Creative Computing back in the 80s came up as a topic on the AtariAge forums. The article is available online an…
... doubt that most Basic versions detect this special case either as ... also suffer from some bus contention caused by video refresh that ... on performance. The CPC's contention model has more impact -- the ...Mr Do! ?Not exactly a new idea (at least twenty-seven years old now :-o), but how about a port of Mr Do! to the Spectrum? There was never an official one, ev…
... address 32768, because the RAM contention messes them up.
contention pattern on a 16K / 48K ... can poll IN 0xFF to detect the appropriate moment, then run ... 't affected by I-register contention, so it can use interrupt ...Mr Do! ?Not exactly a new idea (at least twenty-seven years old now :-o), but how about a port of Mr Do! to the Spectrum? There was never an official one, ev…
... address 32768, because the RAM contention messes them up.
contention pattern on a 16K / 48K ... can poll IN 0xFF to detect the appropriate moment, then run ... t affected by I-register contention, so it can use interrupt ...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…
... certainly no video ula ram contention to contend with mind you ... ?
anyone get bdos to detect external 1-4mb of sam ...What paging scheme is the "standard" for 128K models?Sinclair implemented an arrangement so that even numbered pages are non-contended, and odd numbered pages are contended (quoting from memory, haven't…
... perhaps even smart enough to detect hardware behavior & adapt accordingly ... ]My advice, make the bank contention model switchable - either a jumper ...BUG in zxspin and SpecEmu - read Loading speed in WAV fileI'm created a new save, but it can run at 44.1 KHz, to test it, i make a new file from WAV 44.1 KHz to 88.2 KHz. Load this file in a emulator zx-spin…
... *timming) in T-States to detect 0 or 1 from tape ... 88 KHz. I not add contention of ULA in this test ...
