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Fastest emulator screen renderingHi, I'm developing an algorithm for fast emulator screen rendering and here is what I came up with. 1) Use 4bpp indexed image format as target …
... border changes,
2) calculate the position where ray should be, based ... part of bitmap, starting at position where last instruction finished writing ... -
Places of Speccy interest in Google Street ViewI've noticed that there are a few cities in the UK where Street View is available on Google Maps. No idea since when, I haven't used this feature muc…
... a wall decoration not unlike pixel art from the Speccy, especially the ... very much like a 4x8 pixel font used in some games ... -
Places of Speccy interest in Google Street ViewI've noticed that there are a few cities in the UK where Street View is available on Google Maps. No idea since when, I haven't used this feature muc…
... a wall decoration not unlike pixel art from the Speccy, especially the ... very much like a 4x8 pixel font used in some games ... , back then, hardware manufacturers addresses from the classified sections of Sinclair ... -
Smooth Screen Scrolling RoutineHi everyone, this is a follow up to the thread on smooth screen scrolling. As promised here is the code for the routine. It's pretty long and fairl…
... up the background at various pixel positions. The background data map ... columns to be clipped
;from first tile
... br /> ADD A,A ;then calculate displacement
ADD A,A ... /> * Draw end of row
* If the scroll position is on a ... -
Better arrangement for video memory?While doing some documentation work for the ZX-Uno project, I compared the advantages of the weird layout of the ZX Spectrum against a linear layout.…
... attribute region, in which a pixel can have either a foreground ... the scans for character at position 0,1 ... and bytes 248 ... C64 has 40 character per row instead of 32).
calculate the screen address from the X,Y ... -
ZXSCLZF - Yet another Screen CompressorQuick disclaimer before I continue, this compressor does not shrink screens as small as some of the others posted here, in particular the very good z…
... /> // 32+ means copy from an offset a certain length ... br /> ;;
;; now calculate the memory position to start the copy ... a ; 4t - down one pixel row, stay in char
ld ... 7t - move to next row *** loaded from above
ld e ... -
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…
... his turn in order to calculate when the "wumpus" will ... thereafter 224 cycles per each pixel row. Since the scroll will ... top scanline of the character position row=20, column=0. The ... & 0x01; // OR in single pixel from message char on far right ... -
Move objectHi again, I am using paper colors to represent game objects. I have a "paddle" that is 4 pixels wide. I save its position as a 2 byte word in memory…
... ;543525]Storing the position as an X coordinate (from 0 to 28 ... even a register and easily calculate the real address based on ... ; move high bit rightmost paddle pixel from hl to de
; AT bottom row 1 colomn 1 'score'
How to print logo onto screen at chosen coordinates?Hi, I've just got back into zx spectrum games after all these years and after seeing some of the great games on here I would like to start learning p…
... to specify the position by character or by pixel?
Would you ... >>
PRINTRO:;test from BASIC (otherwise this first section ... ;calculate graphic address in display file
or b ;B =row
More SpecBAS funHere's a neat little effect I lifted from a thread about displaylists and stuff from an Amiga forum - although SpecBAS has no hardware to assist, it …
... , each representing a pixel which we can use ... explanatory - for each row of graphic data, increment ... code]
Now calculate some more values to use ... and MOUSEy return the position of the mouse pointer ... br /> POKE$ writes bytes from a string into a memory ...ZXSCLZF - Yet another Screen CompressorQuick disclaimer before I continue, this compressor does not shrink screens as small as some of the others posted here, in particular the very good z…
... )
;;
;; now calculate the memory position to start the copy ... inc a ; 4t - down one pixel row, stay in char
ld ... br /> cp 0 ; 7t - *** loaded from above
ret nz ; 11 ... 7t - move to next row *** loaded from above
ld e, ...ZXSCLZF - Yet another Screen CompressorQuick disclaimer before I continue, this compressor does not shrink screens as small as some of the others posted here, in particular the very good z…
... require working backwards from the current position following the ... /> ;;
;; now calculate the memory position to start the copy ... a ; 4t - down one pixel row, stay in char
... // 32+ means copy from an offset a certain length ...Printing text, part MMXIIXI'm pretty sure there's been a zillion threads about this already, and I don't think it's the first one by myself either, but here goes. Proportiona…
... exx
; calculate pointer to screen, yofs from table
ld ...
exx
; keep pixel offset within a byte
row of glyphs, next 94 ... data, 2 bytes per shift position.
The ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... .loop:
; blit 8 pixel row to screen
ld a ... next pixel row data
; get the next address from the ... position
; hl = pointer to 8 bytes graphic data
; b = pixel ... inc e
; next row, calculate screen address
pop hl ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... .loop:
; blit 8 pixel row to screen
ld a ... next pixel row data
; get the next address from the ... position
; hl = pointer to 8 bytes graphic data
; b = pixel ... inc e
; next row, calculate screen address
pop hl ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... de ; next pixel row data
; get the next address from the table ...
inc e
; next row, calculate screen address
pop hl ... db 1, 1 ; player start position. This is in collision map ...Robospec (new project, hopefully useful as a tutorial as well)Starting a new project after my graphics investigations. * It's gonna be a Robotron clone since that's not too ambitious (although I'd like to hav…
... br /> ; look up screen address from the table
ld a ... br /> .loop:
; blit 16 pixel rowdata to screen in cells ... br /> inc e
; next row, calculate screen address
pop hl ... horizontal line at any x position
; length may be ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... de ; next pixel row data
; get the next address from the table ...
inc e
; next row, calculate screen address
pop hl ... db 1, 1 ; player start position. This is in collision map ...Robospec (new project, hopefully useful as a tutorial as well)Starting a new project after my graphics investigations. * It's gonna be a Robotron clone since that's not too ambitious (although I'd like to hav…
... position
; hl = pointer to 8 bytes graphic data
; b = pixel ... next pixel row data
; get the next address from the ... inc e
; next row, calculate screen address
pop ... e
; next row, calculate screen address
pop ...Machine Code Sprites Example Code Using Char Based SystemBelow is my WIP code to do smooth screen wrapping sprites using char positions and offsets, as opposed to writing direct to a line (0-191) and shifti…
... can download the snapshot from
[url=" ... /> ; based as opposed to pixel based system
Position
... /> ; ACHAR
; Calculate address of char
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…
... sprites on-screen, aside from non-functional constraints like speed ... row at bottom of the sprite as well as 7 blank pixel ... though these sprites still suffer from the move sprite function overhead ... be remapped to any character position on screen.
...Sprite adviceHello. So, I'm slowly getting to grips with Z80 assembly - currently equal parts frustration and enjoyment. Now looking for some advice to help shift…
... routine that draws a 8x8 pixel spaceship on the screen ... based upon x,y pixel coordinates, which are altered ... Currently, I calculate the screen hl coordinates for each pixel row of the ... rub-out the old sprite position without suffering a horribly ...Pixel Explosion CodeJust a little snippet to cause explosive effects. It uses table lookups for the screen address, and can handle up to 32 pixel particles. A particle…
... /> ; *****************************************************************
; Title: Pixel Explosion
; File: pixel01.asm ... to ensure that from now on the ... particles:
; 0 X Position (If 0, inactive)
...Mode 2 Tile Editor SourceA Timex Mode 2 Tile Editor incorporating a byte mirror table. The compiled version is available in the CSSCGC 2008 collection from the WoS archive. …
... displaying and editing 16x16
; pixel tiles for use with TS2068 ... :
ld a,1 ; copying from the screen
_1st_128 ... first character row
ld bc,$07e0 ; subtract 1761 from hl
sbc hl,de ; calculate how much to add
Tutorial - learn machine code in 30mins[B][I]Message from the moderators[/I] - bigjon has requested that readers' attention be drawn to a better version of this tutorial, one which is easi…
... , from 22528 to 23296, which affects an 8x8 pixel block ... middle of the bottom row in the display file ... /> To save the road position, which we'll need ... right half of the bottom row.
We load ... increment / decrement the car position.
Replace line 43 ...Pixel Color IncorrectHello i am new to the ZX Spectrum and z80 assembly language. I am coding my first game and am having a small problem. I am trying to make the botom r…
... ; set ball's initial x position
ld a ... />
ld (hl), a ; position the ball
ld ... ; if the ooze's row isn't finished being drawn ... The reason only one pixel is drawn is I have ... bottom row in case you are wondering why only one pixel ...BIFROST* Advanced Programming - part 4In previous posts I demonstrated how to move multicolor tiles up and down smoothly by a single pixel, and sideways by an entire char (8 pixels). Thi…
... by a single pixel. Depending on the screen position, the program will ... pixels inside the char column (from 0 to 7). In practice ... '0'+k)
#define printAt(row, col) printf("\x16%c%c ... /> #define printAt64c(row, col) printf("\x16%c%c", ' '+row, ' '+col)
Fastest redraw of screen from UDGsHere's a question for everyone, to generate a bit of code to be used in games: On a standard 48K Spectrum, what's the fastest way to redraw the scre…
... way to redraw the screen from UDGs? The aim is ... the Spectrum's 6K of pixel RAM.
Depending ... main screen at least row-by-row as the UDGs are ... size may be reduced from the full 32x24 if ... enable scrolling in the translation from map to screen.
...BIFROST* for graphic artists - part 1Using multicolor requires 2 very different skills: [I]programming[/I] and [I]graphic design[/I]. I already wrote several tutorials about the former …
... different INK/PAPER colors per pixel line, so you could ... [I]* Graphics by Einar Saukas (from "MIDNIGHT RIDERS FANCLUB" beta version ... by R-Tape, second row of multicolor tiles by na_th_an ... tile exactly in a grid position. The position of any multicolor tile ...Rendering clipped glyphSometimes you need to render a glyph of arbitrary size to the screen. And clip it. For example: drawing a mouse cursor means combining drawing of a…
... Before you do any drawing ... calculate intersection of rows of clipping ... ,
3) Also calculate intersection of columns of clipping ... width is 3 pixels starting from pixel 1 then you store 10001111 ... a letter you AND every row of the screen with the ...
