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Fast way to clear the screen ?So I was wondering fastest way to clear the screen. I've tried this and this works but is it better than CLS ? LD HL,16384 LD BC, 6144 Loop…
... /> LD HL,16384
LD BC, 6144
Loop:
LD A,0
LD (HL ... ),A
INC HL
DEC BC
LD A ... -
Random Numbers, USR Return Values & Timing BASICI've been trying out Jon Ritman's random number routine, published in Your Sinclair Aug'87. Apart from a timing comparison I also did a frequency ana…
... this:
[code]
LD bc,(SEED)
call $2d2b ; ... 38 ;restack,end_calc
LD A,(HL) ;Fetch the exponent of ... divide 'last value'
LD (HL),A ;by 65536 to give ... last value'.
RANDOM0:POP HL ;discard $2d2b ;STACK_BC return ... -
Scrolling loader counter in 85 T-States?Would it be possible to write a scrolling loader counter in 85 T-States? I have a custom screen load routine that loads attribute first, then the …
... /> ld hl,22528 ; attributes
ld de,49152 ; destination
loop2: ld (saveaa+1),hl ... ; save attribute address
ld a,(hl) ; get attribute
ld ... by loader are IX, DE, HL, BC and EX AF,AF'. So ... -
A sped up pixel-shift routine for 1-byte–wide spritesHere’s an optimized (for speed) real-time sprite shifting routine for sprites that are one byte wide. It uses no memory variables for storage of inte…
... sprites, hence the [b]ld hl,(sprite_8x8[/b]) instruction.)
... br />
ld hl,(sprite_8x8) ;point HL to sprite data
push bc ;store counter
ld c,(hl) ;load C ... br /> ld a,(hl)
xor b
ld (hl),a ;place ... -
Copying a single character from one place to another?[code] ORG 33000 LD A,8 LD HL,16384 LD BC,256 LD DE, 18432 LOOP: PUSH AF LD A,(HL) LD (DE),A ADD HL, BC POP AF DEC A JR NZ,LOOP REST […
...
LD A,8
LD HL,16384
LD BC,256
LD DE, 18432 ...
LOOP:
PUSH AF
LD ... A,(HL)
LD (DE),A
ADD HL, BC
POP ... -
Mojon Twins MK2 and lighting effectsDoes anyone have any experience in getting the overlay.h working in the MK2 engine. There were several games written in the churro that used the ove…
... hl
ld (hl), a
ld bc, 29
add hl, bc
ld (hl), a ...
inc hl
ld (hl), a ... -
High score table routineI wrote this general purpose high score table routine. It stores 5 scores and displays them alongside the player names, which are 8 characters long. …
... /> LD HL,THIRD
LD DE,FOURTH
LD BC,2
LDIR
LD HL, POS_3 ... /> LD HL,SECOND
LD DE,THIRD
LD BC,2
LDIR
LD HL, POS_2 ... -
Using BASIC from Machine CodeHi Folks, Came across a very interesting article by Toni Baker in Your Spectrum: http://www.users.globalnet.co.uk/~jg27paw4/yr11/yr11_66.htm …
...
PUSH HL
CALL 5808
LD HL,(23641)
LD BC,130
CALL 5717
INC HL
EX DE,HL
POP HL
LD BC,128
A Neat Redefine Keys RoutinePreviously, I’ve only shared this routine with a couple of people via PM, but I’ve now decided to make it public. I optimized it for size, so it uses…
... )
; ld (control_count+1),hl ;inject # of bytes to check into LD BC,0 ... HL to the code of the first key (dummy_key)
control_count ld bc ... ,0 ;(SMC) count BC keys up (HL will be incremented BC times ...Other than using attributes what other ways to detect collisions, when using char based movement?So I'm slowly working out the bits and pieces to write a game completely in assembly. I've been using attributes when writing in BASIC to detect whet…
... /> ld hl,22528
ld a,10 ; This the row number
ld bc,10 ...
push bc
ld bc,32
LOOP:
add hl,bc
dec ... ,LOOP
pop bc
add hl,bc
ld a,(hl) ; a now holds ...Detecting +3 / +2AWhat's a simple but reliable way to detect if code is running on a +2A/+3? My first though was to try switching to ROM2 and then checking for the …
... [code]detect ld bc,$7ffd ; official paging port
ld hl,$c100 ; address ... to page 0
ld (hl),c ; write test byte< ... 2 bits ignored)
ld (hl),l ; write new byte< ... to page 0
ld a,(hl) ; read byte
...The I register pointing to $40–$7f causes ULA snow and a crash. Or does it?I have heard it from numerous sources, including a few members of this forum, that 128K/+2 machines crash if the I register points to a range of $40–…
... />
ld hl,$f700
ld de,$f701
ld bc,256
ld (hl),$fe
ldir
ld hl,$fefe
ld (hl),$c3 ...How to avoid flicking? IM2 help.Hi, I have started on a quest to make a demo for ZX Spectrum. However the display is flickering and I guess it is something about updating at…
... /> ld bc,two_lines
ld (hl),a
ldir
ld a,(pattern1)
ld bc,five_lines ... /> ld bc,two_lines
ld (hl),a
ldir
ld a,(pattern1)
ld bc,three_lines ...Prportional Ascii text scrollerA couple of years ago I wrote a little scroller that nestles at the top of RAM (FFCA - 65482) and scrolls standard Ascii encoded text from anywhere y…
... ld hl,0fe92h ;character set-1
ld c,(hl) ... ;counter into C
push hl ;save HL
print:
ld ... />
ld (hl),b ;reset counter< ...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…
... /> ld b, 7 (ix)
ld iy, #0x00
add iy, bc
; destination byte can fit 8 bits
ld c ... /> ld h, #0x00
add hl, hl
add hl, hl
add hl, hl
ld e ...converting sna to tapsince i'm struggling to find a simple sna to tap converter that works fine on gnu/linux, i'm about starting to code one on my own (using a scripting …
... /> ld bc,1280
ld de,16834+6912
ld hl,16384
ldir
ld hl ... ,nn
ld de,nn
ld bc,nn ... /> ld hl,nn
ld de,nn
ld bc,nn
ld af,nn
ld ...Help With infinite music on 128KHi :) I'm trying to play infinite simple music on 128K , but i don't know what is wrong with the loop I tried this routine but doesn't work I…
...
ld hl,$FEFF
ld (hl),lowRSI
inc hl
ld (hl), hiRSI
ld a ... /> ld bc,$FFFD
out (c),a
inc hl
ld a,(hl)
ld ...Currah uSpeech ROM Paging and BootyHi, When I emulated the Currah uSpeech for [url="http://www.inkland.org.uk/inkspector"]InkSpector2[/url], I made it page in its own ROM on memory …
... :
ld hl,$a06c
ld de,$fffb
ld bc,$0064
ldir ... of keys collected:
ld a,$11
rst $10 ... /> nop
pop de
ld d,b
di
why am i getting b integer out of range in this code?ive tried running this in spin but thats what i get [code]main org 40000; ; We want a black screen. ld a,71 ; white ink (7) on black paper (0…
... up the graphics.
ld hl,blocks ; address of user- ... ld hl,21+15*256 ; load hl pair with starting coords.
ld (plx),hl ... at his new coordinates.
ld bc,63486 ; keyboard row 1- ... br /> inc hl ; Increment pointer.
ld (seed),hl
...this code wont give me a random starfieldim using a peice of code that ive copied from a book, ignore most of it as it is redundant. for some reason i get a strange random starfield instead …
... up the graphics.
ld hl,blocks ; address of user- ... /> ld hl,3861 ; load hl pair with starting coords.
ld (plx),hl ... at his new coordinates.
ld bc,63486 ; keyboard row 1- ... br /> inc hl ; Increment pointer.
ld (seed),hl
...type in to learn about IM2I'm trying to mess around with learning about IM2 and I found a nice little article in Sinclair User September 1988, issue 78, Page 70-71 [url="https…
... :
ld HL, $5818
ld DE, $5819
ld BC, 7
ld (HL), $57 ;;color ... of attribute different
ldir
ld HL ...Last Problem in Chapter 3 of Toni Baker's Mastering Machine Code on your ZX Spectrum.Chapter 3 of this great book is all about how to use the registers and covers the operations LD, ADD, ADC, SUB, SBC, INC, DEC, SCF and CCF. The la…
... registers and covers the operations LD, ADD, ADC, SUB, SBC ... br /> LD BC, 0 01A000 Init BC to 10
LD DE, 0 ... 61 Copy DE to HL
LD L, E 6B
SBC HL, BC ED42 IF BC is greater than HL(DE) then ... CARRY is set.
LD B, A 47 Store ...Textured Scanline Flood Fill for ZX Spectrum 48KPity that it's quite hard to contribute code to WoS in a straightforward manner. Recently, I have created a textured/hatched fill M/C routine for the…
Pity that it's quite hard to contribute code to WoS in a straightforward manner. Recently, I have created a textured/hatched fill M/C routine for the ZX Spectrum 48K. It was for a text/graphic adventure I'm working on. The algorithm is based on [url="http ...
