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The need of having a 257-byte table for IM2 routinesThis came from a discussion at the speccy.org forum. I have understood that the reason behind the 257-table for IM 2 routines is due to certain joys…
... reason behind the 257-table for IM 2 routines ... all this: is the 257-byte table really needed for [B] ... of kilobyte for the IM2 table, but if space begins ... sacrifice that table and assume that the low byte will be ... assume that the lower byte will be always 255? -
Skool Daze disassemblyWhile developing [url="http://pyskool.wordpress.com/"]Pyskool[/url], I've also been putting together a disassembly of Skool Daze and Back to Skool, m…
... -facing sprite was just a mirror image of the same sprite ... in memory (using a 256-byte "mirror" lookup table) to obtain the right ... Skool also used a lookup table to access text strings, which ... text strings at 32-byte or 16-byte intervals, and used arithmetic ... -
Sprite RotatingI was looking (actually at Everyone's a Wally), and noticed that all the graphics for the main characters are left facing, and two characters wide. …
... />
As Shiru says, the table is not per sprite but ... 512) byte table of pre-reversed bytes means that you can mirror the ... can also make up a table of screen addresses...192x2 will ... -
mirroring bitsIf I have a string of 1408 bytes, each of which has one bit 'b' set, what's the shortest way of mirroring that string, so that each bit set at positi…
You can use an 8 or 16 byte lookup and mirror each half of the byte separately. (16 possibilities for a 4bit half-byte, you can pack 2 into each byte for an 8 byte table, 16 bytes otherwise). -
SpritesYes yes, I know this has been hashed over plenty of times before, but... I have knocked up a quick tiling routine which works with my back buffer co…
... I'm understanding the 256 byte table thing right, you could probably ... if a game uses a mirror table, and it's location, just ... -
im looking for other games like the muncher that use double height and width graphics with colouri havent come across this type of graphics mode on the spectrum before and would like to know if there are any other games that use it.
... be using a lookup table to actually mirror the requisite bytes as ... away with just a 256 byte table for the flip and that ... -
AY musicThis is a format I'm proposing for an AY music player. If anyone can see any problems or anywhere it can be improved please say so. An AY music form…
... previous effects 2bit null 1 byte instrument select - Selects a user ... - 4bit AY envelope waveform 1 byte coarse control - Selects a AY ... Control - 4bit null data 1 byte fine control - Extra data for ... is up to a 512 byte table of 2byte values containing the ... -
Tips on optimizing some newbie assembly routinesI'm starting to learn some assembly language. The best way to learn is to actually code something you are going to use, so I'm creating a very simple…
... grid of characters, a table of characters, and a ... screen the characters from the table. It's some kind ... will read an attribute byte from the grid of ... is just a 2048 byte table of 256 8x8 tiles.
byte for character index, 1 byte for character ... -
Moving a line down the display in assembler?...It's not a "[I]how can I do it[/I]" question, it's more a "am I missing something in trying to do it a new way" kinda question. What I've been doing…
... /> First I'm generating a table of screenaddresses. I [URL="http ... routine that generates a 512 byte table (128 bytes of it wasted ... the start of a 256 byte page.
So, how ... those 512 bytes on a table might earn me a more ... -
Scrolling Bi-Colour Engine for 4-Player GamesJust putting this code up for people to have a look at. Far from finished. Should simply compile and run a bit of a demo. Only good for 128K and +…
... code libraries.
;Use interrupt table at 48640 (190*256) and ... /> di
;Interrupt vector table to go at 190*256 ... />
;Point interrupts to the table:
ld a,190
table
REPT 8,int_sprite_attr_loop
Horizontal scrollDoes anyone know how to do a 2 or 4 pixel left or right horizontal scroll of the spectrum screen. I can make a 1 one pixel scroll with: ... rl (hl…
... supposed you could create a table of values relating to ... you would have a 256 byte table and do something like:< ... to shift
LD H,table ; point to a 256 ... boundary table
LD A,(HL) ; ... get shifted value from table
How good ...Huffman questionI'm pretty sure that the answer to my question is "no", but I just want a second opinion: Is it possible to somehow cram a Huffman decompressor + de…
... you used one byte per symbol in a table to record frequency ... 8-bit frequency in the table gives you 0.2% accuracy ... tolerate more error the 256 byte table can be shrunk. When you ... as the decoder's frequency table.
The actual construction ...Sync-buzzer, interrupts and general confusionBeen wittering on about this in the Misc group, but thought it was best discussed here. Basically been trying to recreate the Sid-Sound effect from A…
... *256 points at a 256 byte table containing interrupt service routine addresses ... the Spectrum needs a 257 byte table pointed at by 'I' ( ... same value in every byte of the 257-byte table pointed at by ... to 0xf100 inclusive. Every byte in this table is set to '0xf1 ...Amiga MOD on ZX SpectrumWell, there were several question about music matters on WOS lats times, so I decided to describe some of my 'adventures', heheh, with MOD playing on…
... routine, look up in a table. The note will range from ... need a 2*296=592 byte period table, assuming 2 bytes per ... /> You'd construct a 592-byte table using this formula, and using ... each note + finetune possibility. This table is available in one of ...Pixel setting / general speccy codingi just started doing some cross-coding with the [url="http://www.bigfatpanda.fsnet.co.uk/z80.html"]Z80 SNA assembler[/url] and an emulator, and this …
... address
LD HL,TAB ; table for pixel
LD C ... it's only an 8 byte table.need help with speed optimization. this procedure draws a sprite with mask from memory onto the screen with x-coordinate in pixels. it doesn't shift sprites in realtime, it just uses …
... thought of using a preshifted byte table. But I think it ... to look up the table for every byte, which is fairly ... you have used a 4KB table.
I ... you do away with the table, and simply store each ... could use a multiplication table to do the time 96 ...need help with speed optimization. this procedure draws a sprite with mask from memory onto the screen with x-coordinate in pixels. it doesn't shift sprites in realtime, it just uses …
The bit I'm most proud of is using the L register for two tasks, as the index for the byte table and also to store the mask. If that hadn't worked I don't think it would have been possible to do without using the alternate registers.need help with speed optimization. this procedure draws a sprite with mask from memory onto the screen with x-coordinate in pixels. it doesn't shift sprites in realtime, it just uses …
Using a shifted byte table makes a lot of sense. I had always been stumped about how to do large sprites. Even for small sprites preshifting them uses a lot of memory.
Good idea Moroz.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…
... trick of having a 257 byte table filled with $ff)
Therefore ...Beginner InfoI have trying to find some hardware information for use with assembly coding but havn't had much luck. For instance. How do I redirect the vertical …
... why you need a 257 byte table deserves some explanation. In IM2 ... makes a 257 byte table all containing the same byte. This will guarantee ... in_inkeytranstbl.asm, which is a table that converts key presses to ... IM2 mode with the 257 byte table as shown by Dr BEEP ...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 …
... /> RST are fast single-byte calls. The fact they are ...
If the 257 byte table doesn't contain identical bytes ... not having a 257 byte table would cause many Spectrums ... has buggered up the table so that a jump ... I'd compare the IM2 table when the game was ...ANN: SP1 for Z88DK (aka splib3, Sprite Pack v3.0)Well it's finally arrived, after a month of "a few days from now" release deadlines. SP1 is the lastest version of splib, a flicker-free software sp…
... at $f000. The rotation table actually begins $200 bytes later ... in the default configuration the table occupies addresses $f200-$ffff ... t need the rotation table. The rotation table is not used to ... tile array is a 512-byte table of pointers. Each entry in ...ANN: SP1 for Z88DK (aka splib3, Sprite Pack v3.0)Well it's finally arrived, after a month of "a few days from now" release deadlines. SP1 is the lastest version of splib, a flicker-free software sp…
... interrupt vector table with a single byte so that ... table must begin on an exact 256-byte page ... SP1.LIB id / type association table address
; * d4f5 ... the entire table with the same byte. This way ... 257-byte table. A "0" would make a 256-byte table, ...Project: M.u.l.e.Wokani came up with a great idea about trying an open-development approach for spectrum games, and I thought why not try with a game I have under dev…
... , 0xd000, 0xd1d1); // create a 257-byte table at address 0xd000 containing 0xd1 ... () call creates the 257-byte interrupt vector table at address 0xd000 (this ...VIC 20 emulation on the SpectrumI'm sure most people are aware of the my attempt at bringing the full Commodore experience to Sinclair users with the "Twenty Commodes" program. It e…
...
; PTR2 points to 256 byte table of worm segment positions
TABLE
TYA
LDY WORMHEAD ...So you want to make a cardgame......but you haven't got a good deck to display. Well here is a fully relocatable routine that will do the job for you. Place the code anywhere in me…
... />
LD H,'PRT_RND ;256-byte table
CURND LD A,0 ...Data bus at interrupt timeIt is "well known" that some peripherals can put values other than 0xff on the data bus at interrupt time, thus meaning that IM2 is slightly more fid…
... cause an ISR fetch from table addresses I*256+255 and ... 'll need a 257 byte interrupt vector table. Everything is not gold ... to use a 257 byte table containing the same byte value repeated 257 ... bytes of the im2 vector table. The interrupt service routine called ...New game: Nanako Descends to HellJust a bit over two weeks after their first game, The Mojon Twins strikes again with a new game for Spectrum 128k and Amstrad CPC: [url]http://www.m…
... thinking to locate the 257 byte table between $8000 and $C000 (compiling ... $8000 and adding a 257 byte static array at the beginning ... , but placing my own jump table looks better, 'cause I'm ...Need help with interrupts againI'm fighting to understand how interrupts code handling works I'm trying to set my simple own interrupt routine, as I don't want to be dependent on …
... me -- you need a 257 byte table, not 256. The most common ... vector byte grabbed off the bus during ... read from the bytes table + 255 and table + 256. That's probably ...
