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P.O.W.As far as I know, a port of P.O.W. (Prisoners of War) from NHK, doesn't exist. [img]https://cld.pt/dl/download/61d19b5e-453b-489c-b17b-d3ed6fccd594/…
...
3. In about 69888 T states (frame duration on a 48K ... /> 224 is the number of T states in a single-pixel horizontal ... 20 * 8 * 224 is the T state 'duration' of the active ... -
P.O.W.As far as I know, a port of P.O.W. (Prisoners of War) from NHK, doesn't exist. [img]https://cld.pt/dl/download/61d19b5e-453b-489c-b17b-d3ed6fccd594/…
... problem is that there isn't enough time in a single ... />
224 is number of T-states in pixel line. What Hikaru ... . Then you have cca 27000 T when writing to screen area ... -
ZX Dandanator! Mini - Cartridge system for SpectrumsHi All, I'd like to present a little HW I've developed during the last three months. It's aimed at providing a console-like usage experience for a…
... />
CMDLOOP: ; Add extra 110 t-states for ~50us pulse cycle (109 ... all data lines, this doesn't make sense.
I ... -
Reading sequential key pressesI am thinking about writing a quick game and have an idea that requires me to read alternate key presses. I’m thinking along the lines of Daley Thomp…
... ="joefish;868228"]Another thing - don't wait for a key to ... what I need. I don't think it can be sped ... anyone can shave a few t-states from the key reading / flag ... -
IXL and IXHI don't know much about undocumented instructions but I get the impression that [b]LD A,IXH[/b] or [b]LD A,IXL[/b] (B, C, D, E also fine, HL not) are…
... HL instruction plus 4 more T-states. That's because they're ... HL instruction plus another 12 T-states. As well as the prefix ... -
Saving and loading data in assembly.I want to add a save and load feature to an project I'm working on. Since it's not that much data in size I thought I'd use the ROM functions, but ho…
... query the running total using t(address).
Not ... ="http://members.shaw.ca/gp2000/T-states.txt"]table of cycle counts ... />
Unfortunately the assembler doesn't have an output format that ... or something but it isn't exactly clear what's the ... -
Running out of fingers in AssemblyDear all, Still trying to learn Assembly and have put a few routines together. However, as my routines become a little more involved I find myself…
... storage. Everything you don't currently need in the CPU ... /> Learn how to count T-States and some common optimizations on ... on the Z80, don't use IX and IY ... / instructions take 19 to 23 T-States!
Use HL, BC ... LD A,(HL) is 7 T-States
LD A,(IX+o ... -
Running out of fingers in AssemblyDear all, Still trying to learn Assembly and have put a few routines together. However, as my routines become a little more involved I find myself…
... class the z80 optimisations and T-state counting as 'intermediate to ... advanced'. Remember, you don't have to learn everything at ... commands
- I didn't count T states or use an interrupt routine ... out that maybe I wouldn't have written such shoddy code ... -
Running out of fingers in AssemblyDear all, Still trying to learn Assembly and have put a few routines together. However, as my routines become a little more involved I find myself…
... Learn how to count T-States and some common optimizations ... than squeezing a few T-cycles from a poorly ... as said above, don't think of registers as ... intermediate values needed. Don't waste a register pair if ... , storing 5*X isn't necessary: once calculated, you ... -
Running out of fingers in AssemblyDear all, Still trying to learn Assembly and have put a few routines together. However, as my routines become a little more involved I find myself…
... go. Learn how to count T-States and some common optimizations on ... results than squeezing a few T-cycles from a poorly chosen ... -
Running out of fingers in AssemblyDear all, Still trying to learn Assembly and have put a few routines together. However, as my routines become a little more involved I find myself…
... loop before you worry about T-States.
And a new assembly ... to run. But it doesn't take very long before a ... -
Running out of fingers in AssemblyDear all, Still trying to learn Assembly and have put a few routines together. However, as my routines become a little more involved I find myself…
... loop before you worry about T-States.
And a new assembly ... to run. But it doesn't take very long before a ... the "nested loop" solution isn't wasted - nested loops are important ... -
Mastering flagsI'm little lost when different flags are set/reset after logic operations, and what conditions must be met. For example, [code] ld a, MODE…
... 8 and more T states. Basically everything that isn't RLA/RRA/RLCA ... -
Optimized (in size) Z80 simulatorI am evaluating Z80 simulators to try to create a tool to analyse z80 programs. I'd like to start with a simple register coverage tool and t-state cy…
... code (or at least show t-states in the editor).
5 ... -
Must be missing the point - machine code... Hi Folks, Trying my hand at machine code again but falling at the first hurdle. I hand crafted the following to run at address 62000 and the co…
... is 7 t-states
INC L is 4 t-states
... 6144 -5 = 141,307 t-states for the original loop
T-States. That's 26% faster ... Unrolling twice saves 55,296 t-states. That's 39% ... Unrolling again saves 64,512 t-states. That's almost 46% ... -
Optimized (in size) Z80 simulatorI am evaluating Z80 simulators to try to create a tool to analyse z80 programs. I'd like to start with a simple register coverage tool and t-state cy…
... /> 3) Your two examples don't do the same thing. After ... you know the compiler won't use these kinds of optimization ... ) That should be relatively easy, T-states at least. Proper profiling with ... -
Optimized (in size) Z80 simulatorI am evaluating Z80 simulators to try to create a tool to analyse z80 programs. I'd like to start with a simple register coverage tool and t-state cy…
... 3) Your two examples don't do the same thing. After ... you know the compiler won't use these kinds of ... That should be relatively easy, T-states at least. Proper profiling with ... between? Then you don't care about A. If ...
Ad 5. You can't do JP HL. But you ... -
POKE taking a variable amount of time...Hi Folks, Does anyone know why the following POKE statements seem to vary in their execution time? [code]100 POKE 60000,10 110 POKE 60001,16…
... . The time delta of ~1000 T-states sounds like a lot though. -
Change JPs by JRsIs there any (easy) way to replace all long jumps with relative ones in assembler code? Of course, I can replace all in text editor, and then place …
... takes 10 T-states and a regular JR takes 12 T-states (if there ... -
Change JPs by JRsIs there any (easy) way to replace all long jumps with relative ones in assembler code? Of course, I can replace all in text editor, and then place …
... takes 10 T-states and a regular JR takes 12 T-states (if there ... -
Proportional fontsI've been doing some proportional font drawing, purely on C level at the moment, but it's orders of magnitude slower than I'd want it to be. It's sti…
... /> Then again, that's 11 T-States to get the two shifted ... that's only 2*4 T-States to get the values.
Proportional fontsI've been doing some proportional font drawing, purely on C level at the moment, but it's orders of magnitude slower than I'd want it to be. It's sti…
... to fit within the available t-states while the loader takes a ... /> Hopefully the whole thing won't increase in size too much ...Cool BASIC tricks and tips!Following on from Dunny's excellent suggestion of a compendium of BASIC tips + tricks, I believe it would be better to have a topic dedicated to it. …
... using integer addresses there isn't much point in using a ... 10101010 will save you 548 t-states per loop.
Try ...Why doesnt this work???Simple piece of code wont do as it should, just want to fill the top 22 lines of screen with an attribute value (150) but it wont have any of it. Som…
... " - ld sp, (nn) is 20 t states compared to just 10 for ...Why doesnt this work???Simple piece of code wont do as it should, just want to fill the top 22 lines of screen with an attribute value (150) but it wont have any of it. Som…
... " - ld sp, (nn) is 20 t states compared to just 10 for ... . On the spectrum you don't often care about these two ... his main code and couldn't figure out why he was ...Graphics program in AssemblyHi so I think I'm getting the hang of this so I've done this program. It writes directly to the screen. I'm using ZX Spin. [code] LD HL,16384 LD B,…
ld hl,(xx) uses 20 T-States. POP uses 10 and PUSH ... involve using up even more T-States and would require extra code ...The state of source level debuggingI was just wondering if we can put on a table everything we collectively know about source level debugging for ZX Spectrum to get an overview of curr…
... /> sprintf(buffer + strlen(buffer), "%04X\t", addr); /* Addr. */
if ... feel better). I included t-states into the decoding tables. ... { opcode, opcode mask, mnemonic, size, t-states, t-states fail }
{ 0x00000001, 0x00040301, "LD ...How would you approach parallax?So ... there is this trick by Joffa that we all know...of waiting for the ULA to reach certain pattern on the screen using the IN command. And then s…
... /> POP HL
}
;; 46 t-states[/code]
Is there ... first time. I need 46 t-states for 2 bytes. Or 736 ... scan lines hence 29.440 t-states. If I can spend the ... rest up to 60k t-states filling emptied column and drawing ...How would you approach parallax?So ... there is this trick by Joffa that we all know...of waiting for the ULA to reach certain pattern on the screen using the IN command. And then s…
[code]
rlc (hl)
dec l
[/code]
Should be only 19 t-states per byte, as opposed to your 23 per byte? Unless I'm missing something.
