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help sought with first foray into machine code - pixel scrolldownI have started to code my first machine code program, a simple roadrace game. I've based it around the pixel scrolldown routine in 40 Best Machine Co…
... file address for first byte in last pixel row
ld bc ... ,d ; now need to get hl to point at pixel row above
to move to character row above
jp ... by more than one pixel, or moving to a push/pop solution ... -
help sought with first foray into machine code - pixel scrolldownI have started to code my first machine code program, a simple roadrace game. I've based it around the pixel scrolldown routine in 40 Best Machine Co…
... be pushing/popping the raw pixel data 2 bytes at a ... the screen address one double byte at a time, right? In ... 'ex(sp), hl'-type instructions to get the saved bytes back ... on the screen starting one pixel line higher? Anyone know how ... -
help sought with first foray into machine code - pixel scrolldownI have started to code my first machine code program, a simple roadrace game. I've based it around the pixel scrolldown routine in 40 Best Machine Co…
... means the z80 has to share access to it with the ula ... 10.5 cycles per byte optimal. The overhead to useful work ratio ... after the end of the pixel row (byte 32) because pushing moves ... reverse sequence we popped to move back toward byte 16 where the ... -
help sought with first foray into machine code - pixel scrolldownI have started to code my first machine code program, a simple roadrace game. I've based it around the pixel scrolldown routine in 40 Best Machine Co…
... half way along the second-to-last pixel line. Is that because ... [/quote]This equals $5800, the byte above the display file and ... the first byte of the attribute file. Why ... stack pointer with the next pixel line up, ie $55f2 followed ... -
help sought with first foray into machine code - pixel scrolldownI have started to code my first machine code program, a simple roadrace game. I've based it around the pixel scrolldown routine in 40 Best Machine Co…
... 1 pixel, and have immediately hit a snag. It seems to work ...
inc l ;point to right byte of left edge
inc ... e ;point to right byte of right edge
xor ... ;point to left byte, left edge
dec e ;point to left byte, right ... -
New Spectrum GameAs some of you may be aware I've been busy working on a Shoot-Em-Up Designer utility for the past few weeks. As the program is pretty much there now…
... smooth as you're likely to get, given that the ... it isn't easy to cheat in the way a ... done on a pixel-by-pixel basis, (well, byte-by-byte actually), and ... bonuses do nasty things to the player if you ... by assigning an unfavourable action to an event. That might ... -
New Spectrum GameAs some of you may be aware I've been busy working on a Shoot-Em-Up Designer utility for the past few weeks. As the program is pretty much there now…
... , and it isn't easy to cheat in the way a ... done on a pixel-by-pixel basis, (well, byte-by-byte actually), and the ... /lasers from my ship seemed to pass right through some of ... -
problem using FRAMES to generate 'random' numbersI realise the pros use bytes from ROM to get their random numbers, presumably because they want to use FRAMES to synchronise the printing and avoid s…
... presumably because they want to use FRAMES to synchronise the printing and ... Anonymous's 32x ldi pixel-scrolling method) to go left or right ... bit of FRAMES (least significant byte) and using the last ... a fix without resorting to calling a byte from ROM?
... -
Collision Detection in SP1Hi, Does anyone have a well-documented example of using collision detection in spritelib. I've search WoS and Z88DK forums but no joy. Something wi…
... = 1 for 2-byte graphical definition else 1-byte, bits 2:0 ... required by the engine for pixel-precise placement horizontally)
< ... is shifted at least 1 pixel to the right, ie only when ... 's pixel coordinates and pixel width/height it's fairly easy to detect ... -
Disappearing/appearing effectI remember doing a small routine in BASIC which could be used to cover the attributes section randomly, until all 704 characters were filled with the…
... would the bits need to be to do a pixel version of this ... , your internal state would have to be at least 15 bits ... /> 3 bits for the inter-byte position;
5 bits for ... /> ~8 bits for the y pixel position.
How do ... -
Disappearing/appearing effectI remember doing a small routine in BASIC which could be used to cover the attributes section randomly, until all 704 characters were filled with the…
... ,
Let me try to get a M/C version ... 't be "decoding" the Y-pixel value - treat the screen as ... bits will provde the inter-byte pixel to set.
The remaining 11 ... ) which defines the byte within the 3rd screen to set.
Disappearing/appearing effectI remember doing a small routine in BASIC which could be used to cover the attributes section randomly, until all 704 characters were filled with the…
... code leaves one (1) unfilled pixel. Good work but incomplete :P ... to you.
{update} Yes, bit 0 of the first byte ... is left untouched and this is due to the ... place).
If it had to be filled, it could be ...Disappearing/appearing effectI remember doing a small routine in BASIC which could be used to cover the attributes section randomly, until all 704 characters were filled with the…
... you're losing that one pixel. Which could "more properly" ... things down in comparison to how you've done ...
And two more adds to the optimization list: "rl a ... as the slower 2-byte and 8 cycle variety ... to "rla" which gets assembled as the faster 1-byte ...Disappearing/appearing effectI remember doing a small routine in BASIC which could be used to cover the attributes section randomly, until all 704 characters were filled with the…
... you're losing that one pixel. Which could "more properly ... br /> And two more adds to the optimization list: "rl a ... as the slower 2-byte and 8 cycle variety ... to "rla" which gets assembled as the faster 1-byte ... anymore!!! You've got to [strike]hate[/strike] love ...Spectrum more loved than C64It just occurred to me that the Spectrum must be more loved than the C64 these days. After all, it has been more than a year since an update was made…
... used 6144 bytes for pixel information, with one byte representing a row ... computers? Since you seem to be new to this whole computer/internet ...Spectrum more loved than C64It just occurred to me that the Spectrum must be more loved than the C64 these days. After all, it has been more than a year since an update was made…
... used 6144 bytes for pixel information, with one byte representing a row ... computers? Since you seem to be new to this whole computer/internet ...Spectrum more loved than C64It just occurred to me that the Spectrum must be more loved than the C64 these days. After all, it has been more than a year since an update was made…
... used 6144 bytes for pixel information, with one byte representing a row ... computers? Since you seem to be new to this whole computer/internet ... per scanline (enabling up to 112 sprites per PAL screen ... and two bitmap graphics modes to produce graphics that were no ...Head over Heels on the C64Dunno if this' a good place to bring this up :D I've been comparing Head over Heels versions and the C64 version is way inferior, everytime there's…
... 4 Mhz, but the pixel layout on the screen is ... speeded up using a 256 Byte LookUp table. I know ... Retro-X does the conversion to all CPC modes, and ... correct table contents (Thanks to Wilko Schr?ter, who ... documentation, I was able to finish this task faster). ...Head over Heels on the C64Dunno if this' a good place to bring this up :D I've been comparing Head over Heels versions and the C64 version is way inferior, everytime there's…
... 4 Mhz, but the pixel layout on the screen is ... speeded up using a 256 Byte LookUp table. I know ... correct table contents (Thanks to Wilko Schr?ter, who ... documentation, I was able to finish this task faster). ... If you actually have to plot individual pixels then ...Help with hi-res 40 column fontI have created a 12x8 pixel font for use with Timex hi-res (Mode 6).
... . I had to write a display driver which took 8x12 pixel characters ... odd number would go nybble/byte.
If memory ... 0 then the nybble/byte routine would have to shift everything 4 ... bits to the right before writing it to the screen. The byte/nybble ...Any BBC aware Specchums out there?After the UK101 and VIC20 emulators I've moved my sights onto emulating a BBC computer. This emulator will be different though in that it will be a Z…
... "? The windows will need to be pixel accurate rather than character square ... byte 'b') with the option of not drawing the first/last pixel ... that uses an 8x8 pattern byte you can use. It is ...Black ScreenHi, Anyone know what would cause a 48k Spectrum to boot to a black screen? you can hear the internals buzzing at power up, but you just get a black…
...
The RAM defaults to a fairly random state (that ... why you sometimes briefly see 'pixel vomit' on turn on). ... you'll either see 'pixel vomit', or black and ... up means that the byte read by the CPU ... them are read simultaneously to form a byte. Usually only 1 ...Looking for a font from a ZX Spectrum game!Some of you know (based on another thread) that I am trying to remake the ZX Spectrum game "Legend" into Flash (for reasons of playability and also t…
... I wouldn't know how to use it as a ... BIN file that Dunny linked to? If I could open it ... character uses 8 bytes. One byte is one row of pixels ... character to the bottom. Each bit in those bytes represents a pixel ... and I'll convert them to the format of your choice ...A video interface for the Spectrum, MSX compatibleSo you can use the same code for displaying sprites, tiles, characteres, and so no, on both the Spectrum and the MSX. That is, the Spectrum now has a…
... pixel tiles or sprites, and if you'll decide to ... which would make them difficult to hack over.
to use either.
byte of memory![/QUOTE]
Good to hear ... to make it easy to hack MSX2 games over to it to ...Question about digitized sound and videoI searched the forums and couldn't find the answer, so here it goes. Regarding digitized sound: I remember reading an article long ago about a vid…
... by placing a 512-byte header at the start ... table rather than a value to load into BC.
... back-buffer, so the pixel data is visibly loaded before ... possible between screen writes, to fill up whatever processor ... having problems getting it to behave the same on ...Screen access in assemblerI am again troubled by the unusal screen design of the Spectrum. :) If I want to do something with, say, a 16x16 bit block of the screen (in the sam…
...
YYyyy yyyxxxxx - bytes in pixel line
| | |
| | ... screen
| |
| |------------ pixel line in character line
to move to the next char line ... ;(8*256 (H is high byte) = 2048 - that is size ...Retro-X Alpha availableChanges from WIP 7 (Alpha 3) to Alpha 4 ( 1.5.08 - 14.5.08 ). Requested by and help by - in brackets. Bugfixes: * Viewer: o File list not displaye…
... then it has to be closed to go back to the converter. This ... ideal solution would be to be able to see the original and ... Byte' instead of 'Bytes"
Area selection doesn't go pixel ... by pixel. This makes it difficult to accurately select ...Retro-X Alpha availableChanges from WIP 7 (Alpha 3) to Alpha 4 ( 1.5.08 - 14.5.08 ). Requested by and help by - in brackets. Bugfixes: * Viewer: o File list not displaye…
... then it has to be closed to go back to the converter. This ... ]
Importer says 'Needs 6912 Byte' instead of 'Bytes"
[/ ... doesn't go pixel by pixel. This makes it difficult to accurately select ... to be Char-wise and not Pixel-wise, as the objects are byte ...Difference in emulator screen sizes and coloursSeeing as Greencard's gone out drinking... I've done a comparison between Spectaculator and ZXSpin. ZXSpin's full screen with border is taller than S…
... programs use the interrupt to synchronize with the frame ... -screen horizon (Aquaplane) or pixel colour (Uridium, for instance) ... pass before the first byte of the screen (16384) ... T state a pixel is written to the CRT, so ... screen and an ATTR byte). The border is 48 ...Difference in emulator screen sizes and coloursSeeing as Greencard's gone out drinking... I've done a comparison between Spectaculator and ZXSpin. ZXSpin's full screen with border is taller than S…
... say that zx spectrum's pixel aspect ratio is not ... matter - you have Overscan to thank for the fact that ... timing, and the last byte of bottom border finishes at ... at a TV connected to a speccy that the ... border really does stretch right to the edges (and beyond). ...
