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Machine code help pls: LDI example[deleted]
... =15, BC=24
LDI copies the contents of address ... -
Machine code help pls: LDI example[deleted]
SkoolKid is correct, except for his first sentence :-)
Yes, it is a typo. The end result of an LDI will indeed be DE=10, HL=16 - [b]not[/b] HL=10, DE=16 - as per the reasoning you've both given. -
Machine code help pls: LDI example[deleted]
Do you really want to play a new cool, interesting, but rather hard game?Just thinking about it... For example, someone will create a game. BIG game. BIG BIG game, with multiple loading scheme, numerous rewind blablabla (o…
... game, you need to avoid contended memory - that leaves you with ... /or interrupt/music routines in contended memory then they will be ... slow - running AY music for contended memory tends to completed kill ...Do you really want to play a new cool, interesting, but rather hard game?Just thinking about it... For example, someone will create a game. BIG game. BIG BIG game, with multiple loading scheme, numerous rewind blablabla (o…
:) Nice. I will never code to Spectrum with contended memory :)I've been wondering...The Spectrum, CPC, and Apple II had no hardware sprites, so what were those 2D objects in their games?
... which (I assume) would be contended by other devices, introducing latency ...ZX81 tape formatIs there a description of it somewhere? The TZX format doesn't give it but can it be worked out from what it says about block 19? There is a good d…
Is there a description of the ZX81 hardware ports used by the cassette interface anywhere? Is there any contended memory issues similar to the Spectrum while writing files to tape?Why did the QL fail?Browsing some old magazines: an advert appeared for the QL, 128k of ram and 32 bit processor etc...also very cheap compared to other similar spec com…
... significantly. This, combined with the contended memory of the QL, and ...Why did the QL fail?Browsing some old magazines: an advert appeared for the QL, 128k of ram and 32 bit processor etc...also very cheap compared to other similar spec com…
... doubly crippled by a heavily contended architecture. With a full 68000 ...Machine code and Basic system variablesSpectrum system variables (I mean 48KB model) are essential for Basic. But what if I started my machine code program and it's never going to return t…
My understanding is that code below 32768 (or something) is going to be contended innit? I suppose that means any code that needs to be run as fast as possible should be above this, right?Clearing the Carry flagI'm reading that sometimes I may want to clear the carry before using ADC or SBC. A simple AND A or OR B will do. However, as I see it, for 8-bit ar…
... a factor that must be contended with as soon as the ...IN 255 behaviour not emulated in Spectaculator and ZXSpinI'm not speaking about "normal" IN 255 behaviour. All of you know what I'm taking about: IN 255 can be used to "read" screen data as it's retrieved f…
... directed to the ULA) as contended I/O if A8-A15 ...Assembler snippetsI was just thinking that a thread for small but useful assembler snippets to do useful things would be cool for people learning z80 coding. Not to me…
... the stack or lots of LDI's.[/QUOTE]
There's ...Assembler snippetsI was just thinking that a thread for small but useful assembler snippets to do useful things would be cool for people learning z80 coding. Not to me…
[QUOTE=karingal;330460]The quickest way is probably the longest and using the stack or lots of LDI's.[/QUOTE]
I remember seeing a piece of code on the forums recently wherein someone made use of the stack pointer to cleverly shift data around.Fastest way to clear a screen.We haven't had an optimizing fun for some time, so let's have some: What's the fastest way to clear a screen (i.e., filling the 6912 bytes at 16384 w…
the same as ldir version, but with
m1
ldi
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ldi
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jp pe,m1Hidden Features In GamesI'm sure there was a thread like this somewhere - sorry, but I can't find it. Hidden stuff in games. In "Mikie" there is a hidden bonus in each of …
... first person to use inline LDI/LDDs for a cheap 4 ...Real 60Hz NTSC 48K ZX SpectrumNot a 3rd party mod. The joystick mod was added by the user, but the board and the computer is exactly what was sold in Chile, South America. We migh…
... see the transition from non-contended memory access to contentded memory ...Real 60Hz NTSC 48K ZX SpectrumNot a 3rd party mod. The joystick mod was added by the user, but the board and the computer is exactly what was sold in Chile, South America. We migh…
... see the transition from non-contended memory access to contentded memory ...Real 60Hz NTSC 48K ZX SpectrumNot a 3rd party mod. The joystick mod was added by the user, but the board and the computer is exactly what was sold in Chile, South America. We migh…
... putting together a generalised "first contended cycle" finder, but can't ...Real 60Hz NTSC 48K ZX SpectrumNot a 3rd party mod. The joystick mod was added by the user, but the board and the computer is exactly what was sold in Chile, South America. We migh…
... see the transition from non-contended memory access to contentded memory ...Real 60Hz NTSC 48K ZX SpectrumNot a 3rd party mod. The joystick mod was added by the user, but the board and the computer is exactly what was sold in Chile, South America. We migh…
[QUOTE=Philip Kendall;346013]I'm putting together a generalised "first contended cycle" finder, but can't guarantee it will be ready by the end of today...[/QUOTE]
Sounds excellent :)Real 60Hz NTSC 48K ZX SpectrumNot a 3rd party mod. The joystick mod was added by the user, but the board and the computer is exactly what was sold in Chile, South America. We migh…
... putting together a generalised "first contended cycle" finder, but can't ...Real 60Hz NTSC 48K ZX SpectrumNot a 3rd party mod. The joystick mod was added by the user, but the board and the computer is exactly what was sold in Chile, South America. We migh…
... putting together a generalised "first contended cycle" finder, but can't ...Detecting Spectrum modelsIs there any sure-fire way a program can detect the model of machine it's running on (48K, +, 128, +2, +2A, +3, clones) even when running in the 48K …
... ; 7, right?), so were these contended when they were in place ... 16K, or were they always contended, even when paged into higher ... any of the other banks contended?
And I know ...Maze Mania - How did they do it?Hi, I was looking at the game "Maze Mania" by Hewson Consultants, written in 1989. The game can be downloaded from here [URL]http://www.worldofspec…
... /> LDI
LDI
LDI
LDI
LDI
LDI
LDI
LDI
LDI
LDI
LDI ...
LDI ...Fastest Block Drawing Code?Following on from my scrolling thread [URL="http://www.worldofspectrum.org/forums/showthread.php?p=351304#post351304"](http://www.worldofspectrum.org…
... along the line. Just use 'LDI' 28 times, then correct the ...Fastest Block Drawing Code?Following on from my scrolling thread [URL="http://www.worldofspectrum.org/forums/showthread.php?p=351304#post351304"](http://www.worldofspectrum.org…
... POP screen address and 28 LDI's is a great idea ... along the line. Just use 'LDI' 28 times, then correct the ...Brand new River Raid remake?one of my friend is trying to make a riverraid remake on flash just to have fun, I checked zx spectrum port of river raid. it is bad, really bad, jer…
... clones that don't have contended memory you could theoretically do ...Brand new River Raid remake?one of my friend is trying to make a riverraid remake on flash just to have fun, I checked zx spectrum port of river raid. it is bad, really bad, jer…
... IR is not pointing to contended memory, which is easy to ...