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Machine code optimisationI'm geting back into z80 coding and wonder what the best way of showing how efficient the code is. I've got Rodney Zaks book and see there are timin…
... ]What are M Cycles and T states?
Looking through the ... or write operation takes 3 T cycles and simple peripheral input ... /output operation takes 4 T cycles (actually extra T cycles could be ... 8 bit microprocessor, takes more T cycles to perform 16 bit ... -
Machine code optimisationI'm geting back into z80 coding and wonder what the best way of showing how efficient the code is. I've got Rodney Zaks book and see there are timin…
... (in bytes) and time (in T-states) for all instructions (although I ... don't recall anymore as many opcodes ... to know exactly how many T-states the code will take, so ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... and Z80)
[*]583 / 1166 T state modulation, 3000baud (timing equivalent ... around 1.5 million free T states per second. Almost enough to ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... 've only got about 300 T-states to do it, and thats ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... ve only got about 300 T-states to do it, and ... since the main loader doesn't need them for anything; ... as if timings weren't already tricky enough when writing ... long as you don't hack them too much[/QUOTE ... . The games themselves wouldn't be hacked at all, ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... for; as if timings weren't already tricky enough when writing ... extra delay of 0-7 T-states for each read or write ... delay is unpredictable. You won't see it when the border ... and beeper sound routines can't be done on a 16K ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... loading screen, but I can't deny its a tempting thought ... .[/QUOTE]If you have the T-states to spare for a loadagame ... agree, that loading screen shouldn't be messed with. I do ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... ROM style encoding. 583/1166 T states.
[QUOTE=stephenw32768;724130 ... on Github, but I don't think you've checked that ... at the weekend. It won't be as fancy an experience ... as Versaload because I won't have time to implement a ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... ROM style encoding. 583/1166 T states.[/quote]That should be perfectly ... -
RCS (Reverse Computer Screen)[B]RCS[/B] ("Reverse Computer Screen", or simply SCR written backwards) is a small utility I'm about to release, that reorders bytes from the ZX-Spec…
... still 27 bytes but 13824 t-states shorter.
[CODE]Smallest ... -
RCS (Reverse Computer Screen)[B]RCS[/B] ("Reverse Computer Screen", or simply SCR written backwards) is a small utility I'm about to release, that reorders bytes from the ZX-Spec…
... still 27 bytes but 13824 t-states shorter.
[CODE]Smallest ... ][/QUOTE]
It doesn't work :( -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... that would leave you fewer T-states in which to do tricks ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... is rather... manual. I don't have a single executable that ... must run in under 25 T-states; and "set_searching_border", "set_pilot_border" and "set_data_border ... 68T, give or take a T-state or so) or once ... -
What would be the simplest tape loading routine?I'm searching for some small assembly snippet I can use to load a (headerless or not) block from tape into RAM I can embed in my C games to load furt…
... /> approx. 14,000 T states. But if
... approx. 2,400 T states; resetting
CP ... 465 T states, plus an additional 58 T states for ... -
What would be the simplest tape loading routine?I'm searching for some small assembly snippet I can use to load a (headerless or not) block from tape into RAM I can embed in my C games to load furt…
... the divIDE and Spectranet won't be able to load your ... /> ld a, 198 ; within 3000 t-states
cp b ; count edge ...
ld a, 203 ; 2400 t-states
cp b ; carry flag ... :
ld a, 22 ; 358 t-states
org 0x05e9
display file addressing; screen slicingWhile working on this Compendium I'm updating or rewriting a lot of stuff. One thing I eventually came to appreciate was the simple & clever way in w…
... to halt for a few T-States so the ULA can do ... frame.
BASin doesn't apply any contention (it makes ... do the job. Humans can't really differentiate when running BASIC ...LZ4 decoderI encountered the [URL="http://code.google.com/p/lz4/"]LZ4 compressor[/URL] a few weeks ago. Reading the [URL="http://fastcompression.blogspot.co.uk…
... reading this correctly (and counting T-states from memory), that saves 8T ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... /> be_ix_plus_3:
nop ; 12 t-state delay
nop ; 8 ... be_h_and_l_lp ; 12 or 7 t-state jump
dec b ... /> jp nz, be_h_and_l_lp ; 10 t-state jump
xor %00010000 ... br /> inc c ; add 16 t-states
jp (ix) ; jump ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... dec b ; reduce by 13 t-states
jp p, sa_leader ; ... /> dec b ; reclaim 13 t-states
inc a ; MIC ... ld a, 198 ; within 3000 t-states
cp b ; count ... /> ld a, 203 ; 2400 t-states
cp b ; carry ...Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... AY programming, so I can't comment with any authority; but ... with an equivalent number of T-states' worth of OUT instructions.
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... and friends using their spare T-states to display countdown timers, but ... possible.
47loader isn't nearly clever enough to do ...Timex 2068 hi-color / hi-res modes.Hello. I know this is not a Timex forum but since it is a very close relative of the Speccy I thought I'd ask my question here. Does anyone know …
... QUOTE=memrah;733821]But wasn't the 2068 ULA very compatible ... a video signal that doesn't work on a lot ... s no reason you couldn't make an SCLD (the ... different, both in the t-states before the screen blank and ... the US).[quote]I don't think software could tell ...Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... 'd need to leave enough T-states to update a counter, but ... hex.
It wouldn't be as elegant as, say ..."Press any key" detectionWhat would be the simplest way to detect if *any* key is being pressed? No LAST_K trickery, I can't rely on that. It has to be reading the keyboard p…
... is larger to count exact T states. The only difference is if ... use in_WaitForNoKey so that doesn't apply here :) Staying within the ... , CAPS or SYM shift won't count as keypresses and in_Inkey ...128k programmingOk, I have had the normal man look (ie. not really), I want a good resource for 128k asm programming. Mostly just to find out how the RAM bank switc…
what advantage is there in using the shadow screen?
you still have to write bytes to both screens to erase them dont you? (which takes up valuable processor T-States)A new full-screen bicolor engine called NIRVANA[I]OK, there's something I need to clarify first: Nowadays if you write [B]"multicolor"[/B] everyone assumes it refers to "multicolor 8x1" (an attri…
... to z88dk, but I don't think it looks impressive enough ... />
You have about 20K T-states available per frame. That's ...bitmap address to attribute addressI've searched, but I don't seem to find the proper keywords. I have a bitmap screen address in DL, character aligned (the address of the top byte of…
... happens. But if you don't have A' tied up you ... operations. Its just those 8 t-states they eat up, maybe a ...bitmap address to attribute addressI've searched, but I don't seem to find the proper keywords. I have a bitmap screen address in DL, character aligned (the address of the top byte of…
... operations. Its just those 8 t-states they eat up, maybe a ...idea: new gaming interface for ZX Spectrum (48k)First of all, I am not an expert this is just an idea of what I would like to see happening in the modern era of the ZX Spectrum. A compact, small, …
... Arduino Nano (although don't quote me on that, ... bus) is 2.5 Z80 T-states. The Arduino Nano running ... will therefore have 11 AVR T-states to respond to the ... it'll take 7 AVR T-states to begin executing your ... leaving you only 5 AVR T-states to get the data you ...
