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Map to screen address problemCan anyone help me out with what I guess is a screen address calculation problem. I need to calculate the screen address of a tile based on a number…
... what I guess is a screen address calculation problem.
I ... need to calculate the screen address of a tile based on ... I have tile 0 its address would be 16384, tile 1 ... to calculate for the other screen thirds.
Could someone ... -
Calculating screen address to alternative ATTR area?I'm using this small snippet of code to convert a screen address to an attribute cell address... [CODE]AttrDE: ld a, d ; get the hig…
... to convert a screen address to an attribute cell address...
... ; get the high byte of screen address
rra ; divide h ... ; de now contains the attribute address
[/CODE]
Screen address of PRINT position...Hi Folks, The following code uses DF CC system variable to extrac the screen address for a PRINT position. [code]100 CLS 110 PRINT AT 10,16;…
... system variable to extrac the screen address for a PRINT position.
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…
... Move to next column, and wrap horizontally if need be
; Vertically wrap char , i.e. if next ... /> ; HL Contains Screen Address
; DE Contains Char Address
; On ...IM2 Machine Code Sprites Example Code Using Char Based SystemFurther to my earlier post, here are sprites running using char method with IM2 driving it Note, for 48k spectrum using TASM [code] ; ***********…
... Move to next column, and wrap horizontally if need be
; Vertically wrap char , i.e. if next ... /> ; HL Contains Screen Address
; DE Contains Char Address
; On ...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…
... /> SCRMODA LD DE,16388 ;screen address of top left
; ... /> LD BC,1760 ;adjust screen address for
SBC HL,BC ... /> ;HL=screen addr.
;DE=address of tile graphics ... /> EX DE,HL ;DE = SCREEN ADDRESS AGAIN
SKIPB ...Help required to calculate screen addressesDoes anyone have some code that calculates the screen address one pixel below the given address ? Is it best to use a lookup table ? Any examples of …
Does anyone have some code that calculates the screen address one pixel below the given address ? Is it best to use a lookup table ? Any examples of this.Optimisation Needed! Is this the Fastest way to copy bytes from screen and back again?I have the screen address (say 0,0 i.e 16384) I want to copy 4 bytes wide by 32 bytes high from the screen to an area of memory. I then want to cop…
I have the screen address (say 0,0 i. ... (4433 TStates to copy from screen to store)
; Clear the screen to show we are bringing ... ; Copy from store to the screen
ld hl, ...RFC: 64 column font codeIn BASIC, type CLEAR 49999 then import the code at 50000. Then type RANDOMIZE USR 50000. This will create a new channel and attach stream #4 to it. A…
... the base
; address to give the correct ... ; row 24?
jr z,wrap ;
zend: ... /> ret
wrap: xor a ;
jr zend ... the row to the base screen address
ld ... the first byte of the screen address
; ...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…
... The SP1 engine divides the screen into character squares, each of ... print double-width text to screen occasionally but the game ... must not wrap across the right side of the screen) and ... h library for the strange screen address manipulators seen in this program ...Help with calculating screen addresses[SIZE=3][FONT=Calibri]I?m having a bit of a coding session whilst at work so can?t spend too much time on my current problem. I?m sure someone on thi…
... just inc or dec the screen address by one. Up and down ... to cross one of the screen thirds. Assuming my cursor starts ...bitmap address to attribute addressI've searched, but I don't seem to find the proper keywords. I have a bitmap screen address in DL, character aligned (the address of the top byte of…
... />
I have a bitmap screen address in DL, character aligned (the ... address of the top byte of ... the corresponding attribute address fiddling with that bitmap address?
I ...Help needed with calculating screen addressesCan anyone help me finally crack Jonathan Cauldwell's screen addressing calculator and, more to the point, is the reason I'm struggling because this …
... the low byte of the screen address.
Finally, ... will give us our vertical screen address. From there we take ... a routine which returns a screen address for (ycoord, xcoord) in ...
X (xcoord) = 2
Screen Address = 20482
...Double-Buffer ScreenFor my Alien Breed Speccy re-write I decided to use a Double Buffer (DB) or 'Back Screen' to draw all the game action onto, before shuffling the whol…
... Buffer (DB) or 'Back Screen' to draw all the ... onto the main display screen. This allows me to ... />
The DB screen sits at mem 25000d and ... hl, 25000 ;Start of DB Screen
ld de, 16384 ... d $40/$48/$50 for screen address
ld a,(cline) ...Spectrum Screen RAM layoutHi there The spectrum screen layout is rather odd. It seems to be arranged into 3 256 byte groups. If I have an x (horizontal) coordinate (from…
... there
The spectrum screen layout is rather odd. It ... BASIC) to generate the appropriate screen address?
I'll see ...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 …
... wrap sprites that go off the sides of the screen ... DE,(SCRADR) ; taking precalculated screen address where to draw sprite < ... LD A,(SPRYCO) ;calculate screen address using a table
... /> LD (SCRADR),HL ;store screen address for sprite drawing
IM2 Machine Code Sprites Example Code Using Char Based SystemFurther to my earlier post, here are sprites running using char method with IM2 driving it Note, for 48k spectrum using TASM [code] ; ***********…
... ; Move to next column, and wrap horizontally if need be
; WCHAR
; Vertically wrap char , i.e. if next ... /> ; converts a screen address to an attribute address
; on entry: de = screen address
IM2 Machine Code Sprites Example Code Using Char Based SystemFurther to my earlier post, here are sprites running using char method with IM2 driving it Note, for 48k spectrum using TASM [code] ; ***********…
... ; Move to next column, and wrap horizontally if need be
; WrapCharVertically
; Vertically wrap char , i.e. if next ... ; converts a screen address to an attribute address
; on entry: de = screen address
Getting scr addresses from x and yCould someone please tell me how to calculate the 8 screen addresses corresponding to a character printed in basic at coordinates x and y? For examp…
... a,(x)
and 31 ; wrap if x>31
lp1 cp 24 ;wrap if y>23
copyudg:
; First get screen address into bc
call getaddr ... ,(hl)
; Move src (screen) address into hl
ld l ...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…
... br /> // buf = destination address for printed bitmap (screen or buffer)
// ... to be applied to the screen address to move down that ... character row and won't wrap to the next line). 2 ... For printing to screen this will be the screen address at the top ...another c64 vs. Speccy site...[url]http://c64vsspectrum.com/[/url] 25 years and we are still brawling.. ;)
... at any byte with a wrap around (so each column always ... good for Z80 handling the screen. This way [B]both[/B ... and vertical movement of current screen address (again, for [B]both[/B ... " and "sprites" on screen. And the initial address calculation in bitmap and ...SAM programmingHi Can anyone provide any example hello world or graphics/sprite printing style machine code routines for the SAM? I can't seem to find anything rem…
... versa, so I get my screen address starting at 0, and in ... is working. (I want the screen at 0, a buffer at ... it wrap like that?
By default is the screen pointer set ...40 Column Printing RoutineI've written a 40 column printing routine, which I'd like to share... It's my first piece of 'public' code so go easy on me! I don't think it is a…
... screen to the screen. ;
; No checking. No wrap ... get the screen address for the ... ; hl - screen address ;
; ;< ...Function with push and popIm trying to see if I understand push and pop when it comes to using to pass parameters to functions: [code] LD HL,16384 LD A,5 Push AF Ld A…
... for pixel placement on screen the engine has to ... form the graphic written to screen.
Here ... /> 202 ;| | |
203 ;|- return address -| \|/
204 ;| | V
...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…
... copy parts of the screen then save them to ... know about the spectrum wacky screen layout for that though). ... to work out the screen address instead of calculating it ... the edge of the screen to the next line ... off the bottom of the screen.
See ...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…
... . A reg will also wrap once it goes over 255 ... (hl) ; e = low byte of screen address
inc hl ; hl points ... of screen address
ld d, (hl) ; d = high byte of screen address< ... br /> ex de, hl ; hl = screen address of cell ...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…
... . A reg will also wrap once it goes over 255 ... (hl) ; e = low byte of screen address
inc hl ; hl points ... of screen address
ld d, (hl) ; d = high byte of screen address< ... br /> ex de, hl ; hl = screen address of cell ...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…
[code]
ORG 32768
FONTBASE EQU #3c00
main:
; make Spin disassembler dissassemble first real instruction correctly
nop
nop
nop
nop
; air supply
; point IX it to the 4 byte ...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 …
... A ;| so, in HL - address for shift table into one ... side, in DE - address for shift into another side ... LD HL,(SPRADR) ; taking precalculated screen address where to draw sprite
address of next bottom line on the screen.
...Smooth Color Masked Sprites using fast page flip on 48kHere is a quick demo of using char based sprites using the Page flip method: a) Background is copied to buffer b) Sprites drawn on buffer c) Buffer …
... />
; CONVERTS A SCREEN ADDRESS TO AN ATTRIBUTE ADDRESS
LD A,H ... :
; HL CONTAINS SCREEN ADDRESS
; DE CONTAINS CHAR ADDRESS
; ON EXIT ...
