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Peeking the contents on screen? How?You will have to forgive me for growing up on the C64, but I know I can peek the location of a character (1024 is top left from memory) and the peek …
... variable RAMTOP indicates the highest address usable by BASIC, and above ... loaded somewhere above the RAMTOP address so they're not ... are arranged more sensibly from address 22528, 32 bytes per ... it complicated to find the screen address of a character (or, ... -
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…
... Pix ; get the screen address for the text
; hl - screen address ;
; ;
; ... -
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…
... push de ; save string address
push bc ... pop de ; get string address
inc de ; ... call Pix ; get screen address and pixel rotation
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…
... ;
; Converts a screen pixel coord into a screen address and ;
; pixel ... Outputs ;
; hl - the screen address for the screen location ;
; a - contains ...Rom routine for pixel addressDear all, Having my bi-annual 'lets try machine code' project again and have come up with a problem with the pixel address rom routine at 8874. …
... $10.
HL contains the screen address and A will contain the ... set the bit on the screen directly.
The bit offset ... is probably not overwriting the screen address with CHR$ $00 which is ...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…
... ADDRESS fdb * ;current address is load address
EXECADD fdb * ;current address is execute address ... value (EOF) munus current address
;****************************
< ... ; point screen to $8000 + row (base screen address + row)
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…
... bc,FONT_ADDR-224 ;add font address - correct for missing sbc ... can add hl,bc for screen address
; Calculate ... represented as %00CCCCCc
;; Formula: screen + ((row & 0x18) 1) ... br /> ld l,a ; screen address LSB is 0 so just ...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…
... advantage. If you have the address of the top byte of ... the high byte of an address in HL, which is equivalent ... is why many people use address tables to save on calculations ... needing to re-calculate the screen address.128k Paging a tile routine to a double bufferHi happy new year all :) Does anyone have an example of how to page a routine to the screen ie a tile routine? Thanks :)
... change the high byte of screen address from #40... to #C0... in ... bit :)
'Before'
Screen begins at: 16384 - #4000 - %0100000000000000 ... - %0101100000000000
'After'
Screen begins at: 49152 - #C000 - %1100000000000000 ...Problem with BC corrupting after DJNZJust for fun, I'm messing around trying to get the level maps from Lemmings to display on the screen with machine code. It's been ages since I did an…
... ] INC E ; ADD 256 TO SCREEN ADDRESS TO GET TO NEXT LINE ... /> For reliably stepping down the screen one line at a time ...Problem with BC corrupting after DJNZJust for fun, I'm messing around trying to get the level maps from Lemmings to display on the screen with machine code. It's been ages since I did an…
... COUNTER
PUSH DE ; Save screen address
LD BC,32 ... ; Get original screen address
INC D ; ADD 256 TO SCREEN ADDRESS TO GET ...128K programmingDoes anyone know any good resources on assembly programming for the 128? All I'm after is an "idiot's-getting-started-guide" on how to utilise the…
... only page in the alternate screen (bank 7) at ... write to it, at address 49152. You can't ... to memory at the usual screen address at 16384. Bank 5 ... and write to the screen at address 49152, then immediately read ... the same data back from address 16384, as the same ...I don't think I'm getting the $22AA Pixel-Add rom routineDear all, I'm misunderstanding how the PIXEL-ADD rom routine works. My code... [code]ld b,175 ld c,1 call $22AA ld (hl),a ret[/code] So…
The screen is made up of bytes ... of bits. Visually in a screen line on the Spectrum, ... screen simply means writing a certain value at a certain address ... is finding out the byte (screen address) to write the pixel ... to be written on the screen somehow. So what we ...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
...Let's copy buffers!Figured I'd do some double buffered graphics, so I can render for several frames before displaying stuff. Yes, I mean on a 48k speccy, so no 128k spe…
... table must be located at address like $??ff)
lookup:
push af
; calculate screen address at right side
ld ... af
; read next screen address from lookup table
next ...Let's copy buffers!Figured I'd do some double buffered graphics, so I can render for several frames before displaying stuff. Yes, I mean on a 48k speccy, so no 128k spe…
... push af
; calculate screen address at right side
ld ...
; write 12 bytes to screen (right side)
ld sp ... br />
; read next screen address from lookup table
next ...Let's copy buffers!Figured I'd do some double buffered graphics, so I can render for several frames before displaying stuff. Yes, I mean on a 48k speccy, so no 128k spe…
... ;858566"][code]
; read next screen address from lookup table
next ...Let's copy buffers!Figured I'd do some double buffered graphics, so I can render for several frames before displaying stuff. Yes, I mean on a 48k speccy, so no 128k spe…
... ;858566"][code]
; read next screen address from lookup table
next ...Z88DK NOOB cplot INK colorHi I am a complete NOOB with Z88DK, I am trying to draw colored circles. How does ink, paper and border work with Z88DK. I started trying to wo…
...
; de = screen address
; l = bitmask
... ex de,hl ; hl = screen address
call asm_zx_saddr2aaddr ... /> zx_saddr2aaddr() stands for "screen address to attribute address".
zx_px2bitmask ...Help needed with MIA software with custom (?) loaderHi, I've got into my hands recently a bunch of Polish educational software which are unknown MIA on WOS. I believe they are protected with some…
... EB55 ; Call Sub1 (update destination address)
0xEB37 DEC DE ; Decrease ... />
;Update destination (screen) address in IX
;Screen goes from
;16384 ... bit to put it inside screen address space
0xEB74 LD ...ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... performs a read from this address area.
[b][i ... it will be overloading with screen address range, although ULA, will still ... be used while writing to screen.Some Graphic Coding & Audio help.Hello my fellow WoS'ers I am in the process of writing some code for graphical purposes - I have Z88DK raring to go but I do not know how to take…
... to some free address and decompress to the screen (if using ... on screen (see the zx screen address functions that manipulate screen addresses ... br />
This free address block can be reserved inside ... load the disk data to address "buffer". You can also ...Must be missing the point - machine code... Hi Folks, Trying my hand at machine code again but falling at the first hurdle. I hand crafted the following to run at address 62000 and the co…
... HL,$4000 ; Load HL with screen address $21 $00 $40
62009 ... ; POKE bit pattern in to screen memory $77
62017 INC ... L ; Next screen byte $2C
62018 DEC ... INC H ; Next row of screen bytes $24
62025 LD ...2x2 tile to attribute blocksHow do you go about converting a 2x2 tile to 16 x 16 attributes? Heres an example of the tile data I'm wanting to enlarge. [code] defb 255, 25…
... enlarge
LD HL,22528 ; screen address
LD A,255 ; the ... ),C ; put the colour on screen
notsetattr1 INC HL ; ...Must be missing the point - machine code... Hi Folks, Trying my hand at machine code again but falling at the first hurdle. I hand crafted the following to run at address 62000 and the co…
... HL,$4000 ; Load HL with screen address $21 $00 $40
62009 ... ; POKE bit pattern in to screen memory $77
62017 INC ... L ; Next screen byte $2C
62018 DJNZ ... INC H ; Next row of screen bytes $24
62023 LD ...Must be missing the point - machine code... Hi Folks, Trying my hand at machine code again but falling at the first hurdle. I hand crafted the following to run at address 62000 and the co…
... HL,$4000 ; Load HL with screen address $21 $00 $40
62006 ... ; POKE bit pattern in to screen memory $77
62009 INC ... L ; Next screen byte (256 iterations) $2C
screen!
Only taken me ...2x2 tile to attribute blocksHow do you go about converting a 2x2 tile to 16 x 16 attributes? Heres an example of the tile data I'm wanting to enlarge. [code] defb 255, 25…
... /> LD HL,22528 ; screen address
LD B,80 ... /> POP HL ; recall screen address
POP DE ; ...Must be missing the point - machine code... Hi Folks, Trying my hand at machine code again but falling at the first hurdle. I hand crafted the following to run at address 62000 and the co…
... fill 1/3 of the screen?[/quote]
1/3 ... $800 hex + $4000 for the screen address = $4800.
$4800 in binary ...Must be missing the point - machine code... Hi Folks, Trying my hand at machine code again but falling at the first hurdle. I hand crafted the following to run at address 62000 and the co…
... HL,$4000 ; Load HL with screen address $21 $00 $40
... br /> 62009 INC L ; Next screen byte (256 iterations) $2C
62011 INC L ; Next screen byte (256 iterations) $2C
62013 INC L ; Next screen byte (256 iterations) $2C
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;…
DF_CC is the address of the top byte ... is specifiied.
The screen address calculation is split across two ... br /> $0E9B CL_ADDR calculates the address of the row;
$0DD9 ... CL_SET calculates the address of the column within the ...
