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Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... :
[CODE]LD HL,$1234
LD HL,$5678
LD HL,$8765
LD HL,$4321[/CODE]
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... :
[CODE]LD HL,$1234
LD HL,$5678
LD HL,$8765
LD HL,$4321[/CODE]then ...JP (HL) confusionokay.... JP nn will jump to memory address nn. JP (HL) ,I assumed would read the contents of memory address HL and jump to the location and be a gre…
... other words
[code]
LD A,bytetocheck ; Has to be ... 2
LD L,A
LD HL,jumptable
JP (HL) ; read/peek ... the contents of HL and ... jumps to the memory location HL
Looking ...Sort 2 byte words (x, y) on ypos, also question about swap (DE), (HL)Well that was a lot of debugging ;) But if you want a routine which takes an array of 16 byte words x, y and then sort them on y (ignoring x), I'm…
... ; 4
ld a, (de) ; 7
ld (hl), a ; 7
ex af, af' ; 4
ld ... ; 4
ld a, (de) ; 7
ld (hl), a ; 7
ex af, af' ; 4
ld ... pop af
pop hl
ld c, a
jr ...Breakpoints and other questionsSome games have LDIRs, LDDRs, ANDs and XORs before they jump to the real start address (and some other stuff that I don't understand yet). If I want …
... them:
ld af,$1234
ld bc,$5678
etc.
hl to what af', bc' etc ... bc, de and hl with bc', de' and hl'.
Also ...Console frameworkStill working on Specotron, but at the point where working out the diagonal lines collision is not good at beer o'clock. In the meantime I've knoc…
... input beyond cursor
CAPS+5678: Move cursor within input buffer ... br /> ld l, a
add hl, hl
add hl, hl
add hl, hl ; HL = char ... br /> ld hl, cursor_row
dec (hl)
ld hl, cursor_prev_row
dec (hl)
ld a ...Assembler code from tutorial, problem!I was wondering if anyone could help me decipher this z80 assembler code? ORG 60000 LOAD 60000 EA60 21BCEA LD …
...
EA60 21BCEA LD HL,NMBRS ;HL = start of digits
EA63 ... update it
EA67 77 LD (HL),A ;replace digit in memory ... not, else
EA6C 3680 LD (HL),80H ;reset digit to zero ...Short Z80 QuizQ1) Which program gives different result ? A) XOR A ADD A,A B) XOR A ADC A,A C) SCF ADD A,A D) SCF ADC A,A Q2) What is the equivalent of NEG …
... /> LD B,10
LD HL,60000
LOOP: LD (HL),B
INC HL
LD BC,10
LD HL,60000
LOOP: LD (HL),C
INC HL
DEC BC
LD ...VSYNC FunctionI have written a VSYNC function, so that I can clear the screen before redraw without flicker on the screen, I do this by peeking at the address 2367…
... /> VSYNC:
EI
LD HL,(vsyncst)
VSYNCLP:< ... br /> LD A,(23672)
CP L ... /> JR Z,VSYNCLP
LD (vsyncst),A
DI< ...How to get Grahics to wrap vertically around the screen?I am using the following code to draw an image to the screen. First I use HL to contain ROW and COLUM I then call the MapScreenFunction As I draw m…
...
prtiv1: ld a,(de)
or (hl)
ld (hl),a
inc ... de
inc l
ld a ... ,(de)
or (hl)
ld (hl),a
inc ...FAST PIXEL DRAWINGI'm looking for the fastest way to put a pixel to the screen (on spectrum ofcoz:). Here is my own procedure (written in PASMO). But I don't how do it…
... br /> putpix proc
ld a,e ; 0-63 or ... /> ld c,a
ld a,(bc)
ld b,(hl)
or b
ld (hl), ...TASM, Z80 and Spec emusHi! Having some novice questions here regarding TASM and writing machine code for the Speccy emus... Now I have configured TASM into my EditPlus and…
... /> LD HL,16384
LD (HL),255
INC HL
LD (HL),128
INC HL
LD (HL ... ),255
INC HL
LD (HL ... ),128
INC HL
IM 2 interrupts and smooth scrolling - easy peasy!Okay, been fiddling around with IM 2 and have actually mastered (I think) how to use IM 2! Now I run my game Ragnar Revival in IM2 and use HALT to sy…
...
push hl
ld hl,16384
inc (hl)
pop hl
ei ... 58853
ld (hl),229
ldir
ld hl,58853 ;Create a ... : lsb,msb
ld (hl),0BAh
inc hl
ld (hl),088h
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 …
... /> ld hl, lineptrs
add hl, de
add hl, de
ld e, (hl)
add hl, de
ex de, hl
ld hl, pixelmsk
ld a, c ... /> ld b, (hl)
ex de, hl
ld a, (hl)
xor b
ld (hl ...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 …
... br /> EXX
LD HL,(SPRADR) ; taking precalculated screen ... LD A,(HL)
AND B
OR C
LD (HL ... ),A
INC HL
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…
... )
LD D,0
LD HL,gfx
ADD HL,DE
ps01:
LD E ...
PChar:
LD A,(DE)
LD (HL),A
INC DE ...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] ; ***********…
... )
LD D,0
LD HL,gfx
ADD HL,DE
ps01:
LD E ... pp1:
ld (hl),C ; LD (0FE00h),FDh
inc hl ; repeate 253 times ...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 …
... /> INC HL
LD (HL), D
INC HL
POP DE
LD (HL), E ... /> INC HL
LD (HL), D
INC HL
POP DE
LD (HL), E ...Smooth Masked Sprites using fast page flip on 48k Part 2Ok, After all the suggestions in Part 1, which were all excellent (Thankyou), I opted on the following: I have 2 x 6k Offscreen areas (Yes, that's …
...
prelp:
LD (HL),%11111111
INC HL
LD (HL),%00000000
INC ... /> LD HL,SCREEN+16 ; Destination
LD (hl3+1),HL
EXX
LD HL,BACKBUFFER ...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…
... DI
LD (SCRMODA+1),HL
LD HL,(SCRPOS) ;SCROLL POSITION ... /> SBC HL,BC
LD A,(DE)
OR (HL)
LD (HL),A ... /> LD HL,(MODHLB+1)
LD A,(HL)
INC L
LD H,(HL ...The incredible shrinking screendumpIn this topic I stated that I would be impressed if the screendump could be smaller than 37 bytes. [url="http://www.worldofspectrum.org/forums/viewt…
... , B 0
nline ld hl,table-1 ; Use JR value ... 0 after 256 times
ld b,(hl) ; B = high byte ... next byte in table
ld e,(hl) ; Fetch 'last' byte ... in table
prbyte ld a,(hl) ; Fetch byte for print ...Help needed to speed up functionCan anyone help me to re-factor this code snippet. The "MAP" section holds information about which tiles go where on the screen (handled by another f…
... NOTDIRTILE PUSH HL
LD (HL),A
INC L
LD (HL),A
LD (HL),A
INC L
LD (HL),A
POP HL
INC HL ...Anyone help re-factoring a tile functionI had some excellent feedback for re-factoring my function that displays the colour for my screen tiles. Can anyone offer some help to improve the fu…
... />
PRINTTILE LD B,16
MAPLUMODIFY LD HL,(MAPLOOKUP) ; This value ... ,(HL)
LD (DE),A
INC HL
INC E
LD A,(HL ...Fastest way to write something to screen$Hi, I just got pasmo.exe and start playing with attr scrolling, well, not scrolling, just write different values to a block and see if I can introdu…
... sure about the push vs ld (hl),a.
NOTE: This ...
LD (OLDSP),SP
LD SP,base+len
LD BC,len/2
LD D,val1
LD E, ...
DEC BC
LD A,B
OR C ... br /> JR NZ,LOOP
LD SP,(OLDSP)
ENDM ; SFILL ...Best method for sprite collision detectionHi, I have been trying to incorporate collision detection into a sprite routine I writing. The following is what I have come up with so far: POP D…
... mask, d=sprite image
LD A,(HL) ; hl = screen addr.
AND ... detected
EXX
INC (HL) ; increase if there is a ... br />
NC0:
LD A,(HL) ; draw sprite as normal
OR D ;
LD (HL),A ;
INC L ;
Programming MC : first stepsIsn't nice to collect all kinds of short routines to help making the first steps into MC for everyone who never touched MC? What I mean is mostly th…
... />
start ld hl,(23672)
ld (seed),hl ; RANDOMIZE equivalent
ld a,6 ... does 0 n-1
ld hl,(seed) ; fetch RND pointer
MC TipPlace your MC tip here: Here is my first: When using alternate registers (EXX) the HL register must not be affected on return to BASIC. Also the IY…
... alternate registers (EXX) the HL register must not be affected ... start
exx
ld (savehl),hl
exx
........ ; do ... program
exit exx
ld hl,(savehl)
exx
ret ...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…
... /> ld hl,16384
ld (c2sc_dest+1),hl
ld hl,store
ld (c2sc_source+1),hl
Machine Code: quicksort optimisationI came across this z80 quicksort implementation when going through the wikipedia article on the same. It's 44 bytes long. I was wondering if any of …
... /> qsort ld hl,0
push hl
qsloop ld h,b
ld l ... /> ld (bc),a
ld a,h
ld (de),a
pop hl ...Spin save dissembly problemHey Dunny and others Spin dudes! There seems to be a small problem with the save dissembly function from the dissembler in Spin. This is the exact o…
... /> ld hl, l29699 ; 26564 10ts
ld (26511 ), hl ; 26567 16ts
ld hl, l29735 ... ; 26570 10ts
ld (26513 ), hl ; 26573 16ts
ld hl, l29708 ...
