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Pocket Clive - 2 QuestionsHello, I've just started using Pocket Clive on my iPaq pocket PC, excellent emulator BTW. 1. I have just wrote a small BASIC program to randomly pi…
... ' method undoubtedly uses up more T-states than the 'floating bus' probe ... the same genre (I haven't yet looked at the game ... -
Keyboard emulation accuracyWhen the IN function checks the keyboard how accurate is it in a real speccy? For example, say you had lightning fast hands and a keyboard that coul…
... than 11 T states. Basic command IN takes probably several thousands T states - there ... will be many T states between keypress or ... -
Convert x,y to Attribute Address in AssemblyWhat is the fastest way, given x,y (in hl) to return the attribute address?
Yeah, that'll do it nicely. Adds another 70+ T-States to the routine tho'. Personally I'm not a fan of using ROM routines unless I'm going for space-saving code, but that's just me.
Should give Rob a few ideas to try out anyway. -
Convert x,y to Attribute Address in AssemblyWhat is the fastest way, given x,y (in hl) to return the attribute address?
... want to save 30-odd t-states at the expense of a ... -
Method to read byte as binary string rather than dec?Hi all Am fiddling around with the screen buffer and have written a routine to scan the screenbuffer into upper ram and then write it back in upside…
... faster.[/quote]
Can't do that on a Spectrum ... data would take about 5000 T-States or so (clock cycles basically ... -
Method to read byte as binary string rather than dec?Hi all Am fiddling around with the screen buffer and have written a routine to scan the screenbuffer into upper ram and then write it back in upside…
... :32, cyborg wrote:
Can't do that on a Spectrum ... data would take about 5000 T-States or so (clock cycles basically ... /> The ZX has approx 70000 T-States per frame, but this depends ... would take about over 40000 T-States, and that's not taking ... -
The New SPIN releases ThreadOk, as I'm now working on SPIN again full-time, and as a very wise man once said, "Release Early, Release Often"[1]... I'm going to release new SPIN…
... , min, and average number of T-States it takes to pass through ... -
The New SPIN releases ThreadOk, as I'm now working on SPIN again full-time, and as a very wise man once said, "Release Early, Release Often"[1]... I'm going to release new SPIN…
... , min, and average number of T-States it takes to pass through ... -
Screen DisolveHas anyone got any good assembly code to dissolve the screen I could see
...
dec c
jr nz, fx_clear4
ret
[/code] -
Codies help? Werewolves of LondonHi All, never one for shying away from the deep end, having only just dipped my toe in to the world of machine code I find myself trying to find out …
... ]
What you haven't noticed is that an interrupt ... - it's at 69886/69888 T states as you can see from ... overflow maybe? The code doesn't make much sense at that ... -
unused assembler commands?Z80 processor has commands like OUTI OUTD OTIR OTDR INI IND INIR INDR.They deal with sending /reading bolcks ofinformation to ports. The problem is, …
... )
ld a,$0d
jr nz,_STp_output1
sub $03
ret
[/code1]d
jr nz,_STp_output1
sub 3
Assistance with IM2 routineI subsequently got a working IM2 routine.
... the table so I don't have to recalculate all the ... /> Anywhere, really. Assuming you don't want it in the ROM ... already sacrificed quite a few T-states to enable the mixed mode ... 's a lot of wasted T.Run Length DecodingRun length encoding/decoding is far less efficient than using a modern compression program.
... /> or a
jr nz,del1
ld a ... /> or a
jr z,del1
del2: ... jr z,del3
pop af
dec a
jr nz ... ,del2
jr del1
del3: ...Run Length DecodingRun length encoding/decoding is far less efficient than using a modern compression program.
... dec c ;next column ?
jr nz, unpak_scr4
ld c, 96 ... 221
dec l
jr nz, unpak_scr4 ;last col ?
...
dec c
jr nz, unpak_scr7
ld c, ... br /> dec l
jr nz, unpak_scr7
pop hl
How to speed up TZX loading (emu development)With many newer emulators there are options to do faster loading schemes, even for turbo-loader or protected loader blocks in TZX files. For example,…
... to run as usual. Wouldn't I have to bodge R ... info, or even fiddle the T-states to ensure adequate frames have ...Speccy 128k Double Buffering.If I understand this right, you display either of the screens, and draw to the one that is not being displayed. Am i right in thinking that the Non …
... , timed so that you don't get a shear effect.
T-States (call it 40 if you ... second screen, and still won't compare time-wise.
Biotoxins redumping projectI've been spending quite a bit of time between dumping STP / MIA titles at looking at the titles flagged by Biotoxin as possibly needing a redump... …
I had to use an old version of CSW Viewer on GFOL side 2. The 0 bit is 563 and the 1 bit is 810 T States. 16642 bytes. The pilot tone looks normal. What did you find Mikie?Biotoxins redumping projectI've been spending quite a bit of time between dumping STP / MIA titles at looking at the titles flagged by Biotoxin as possibly needing a redump... …
... the 1 bit is 810 T States. 16642 bytes. The pilot tone ... really arcane stuff! You aren't by any chance working for ...MAME on the Spectrum?Yes, I know it's currently AY's job to make ludicrous posts (a position he's filling in very well, until TKRAP returns), but just out of interest, if…
... opcodes only use so few T-states, making it slower on a ... the APPLE I emulator however states that it is only a ...Checksum RoutinesHi there everybody, Does anyone have an 'off the shelf' assembler routine for generating checksums? Thanks Jim
I've also found this example at [url]http://wikiti.denglend.net/index.php?title=Z80_Routines:Security:CRC16[/url]
CRC16:
;Borrowed from [url]http://zilog.sh.cvut.cz/~base/misc/z80bits.html[/url]
; and moddified to be a loop
; ...Checksum RoutinesHi there everybody, Does anyone have an 'off the shelf' assembler routine for generating checksums? Thanks Jim
... ; that is, initially zero.
JR NZ,L1F49 ; skip forward to PAUSE ...Checksum RoutinesHi there everybody, Does anyone have an 'off the shelf' assembler routine for generating checksums? Thanks Jim
... ; that is, initially zero.
JR NZ,L1F49 ; skip forward to PAUSE ...RealXThis may be a dumb question but will RealX ever get released?
... different offsets used to count t-states, that's all.
Anyway ... 48K timings with a logic states analyser and a CPLD circuit ... find the real values for t-states offsets (first contention, electron beam ...In Machine Code, what is the quickest way to sort bytes?I am playing around with some ordering of sprites, where I want to order them by vertical position. I used some Rodnay Zaks code to order some bytes…
... br /> cp b
jr nz,sort1
;djnz sort1< ... d
or a
jr nz,sort0
ret ... /> dec e
jr nz,Finish ; If E became ... br /> dec c
jr nz,Step
Finish:
...How to speed up TZX loading (emu development)With many newer emulators there are options to do faster loading schemes, even for turbo-loader or protected loader blocks in TZX files. For example,…
... each time).
* Number of T-States since last check must be ... 128. The actual number of T-States needs to be recorded for ... with the same number of T-States having elapsed as before, and ...GP2X handheld - ZX Spectrum emu goodnessIt's probably been covered here before, but I've spent the last week going crazy over the GP2X Linux-based, dual-core handheld that can emulate somet…
... ,INIR,OTIR,OTDR) execute 8 t-states faster than they should. I ...The Only Reason Sinclair Succeeded (Provoking Controversy)Although I love my Sinclairs dearly, I think that the only reason they succeeded was because at the time most people did not know any better (factori…
... Z80 instructions that take 23 t-states are ones that involve ... instructions that take over 12 t-states that I'd commonly ... pointers and typically take 5 t-states. Seeing as the equivalent register ... take between 13 and 16 t-states, but again their 6502 ...The Only Reason Sinclair Succeeded (Provoking Controversy)Although I love my Sinclairs dearly, I think that the only reason they succeeded was because at the time most people did not know any better (factori…
... sort routines and counted the t-states in each step:
... There are an initial 28 t-states used in the Z80 ... sort loop takes 22 t-states on the Z80, and ... br /> Comparing elements takes 114 t-states on the Z80 if a ... 1 iterations takes 15 t-states if failed on the ...
