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machine code loadercan someone have a look at this loader and break down what its actually doing and also how i can stop it from executing the 2 loads of headerless blo…
... ORG $5B00
LD HL,BASIC
LD (23641),HL ;E_LINE=address of BASIC ... ORG $5B00
LD HL,BASIC
LD (23641),HL ;E_LINE=address of ... ;Signal line execution
LD (IY+10),1 ;NSPPC ... -
machine code loadercan someone have a look at this loader and break down what its actually doing and also how i can stop it from executing the 2 loads of headerless blo…
...
LD HL,(23613) ;(ERR_SP)
LD (HL),$EF
INC HL
LD (HL),$D1 ;return ... after loading program
LD HL,BASIC
LD (23641),HL ;E_LINE=address of BASIC ... -
Undefine functionHere's a routine to selectively remove variables from the VARS area and reclaim the space. This can be done partially from BASIC already by assigning…
... AEDCB
E_LINE: equ 23641
CH_ADD: equ 23645 ... UNDEF: ld hl,14
add hl,sp
ld sp,hl ;undo USR ... STRARR: inc hl
ld c,(hl)
inc hl
ld b,(hl) ;BC= ... -
joining lines of BASICDue to overwhelming demand - well, one demand - well, more of a suggestion, really - here's a routine to join together lines of BASIC. The vertical c…
... DE,HL ;DE=new cursor position
LD HL,(23641) ;E_LINE
SBC HL,DE ...
JR C,DOMOVE
ld a ... -
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
LD HL,(23613)
PUSH HL
LD HL,BACK
PUSH HL
LD (23613),HL
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…
... word2
MACRO swap_word
ld a, (hl) ; 7
ex af ... , af' ; 4
ld a, (de) ; 7
ld (hl), a ; 7
ld a, (de) ; 7
ld (hl), a ; 7
pop af
pop hl
ld c, a
jr .heapify_words_body ...saving part of a BASIC programHere's a short routine to save part of a BASIC program. The idea is that it can be merged into a program and then used to save sub-routines, etc. to …
Here's a new version of my routine which now allows multiple saves and saving of variables; even so, it's about 80 bytes smaller than the original version (about 1kb). To save space the m/code is now in a DATA line instead of a separate variable. The first ...128 BASIC-compatible way of loading BASIC as code?On a 48K Speccy (or from 48 BASIC or USR 0 mode on a 128K machine), one can do a silly trick like this: [code];; load a 4000 byte BASIC program ld i…
... /> LET ELINE=FN p(23641): POKE 23627,PEEK 23641: POKE 23628,PEEK ... />
ld hl,(23613) ;(ERR_SP)
ld sp,hl ;reset stack
ld hl,$1b9e ...that "listing variables during runtime" thingWell, I did eventually finish this, but with my meds playing up I don't have much time each day that I can spend at the computer, so it's taken rathe…
I've updated FindVars (the precursor to DumpVars) to include the feature from DumpVars which assigns a separate variables area for the routine so its own variables don't get mixed up with the other program (the old version is in the [url=http://www.users. ...LINE-routine and other nice pieces of codeThe line-topic came in the end with a nice piece of fast coding. I think that there might be more of these routines out there (where-ever-u-r). Isn…
... me..)
INIT...LD B,hightable ; B = constant ... through the program
.......LD DE,0
.......JP ... /> .......LD L,A ; HL points to highbyte (4)
.......LD H,(HL) ; ... fetch highbyte (7)
.......JP (HL) ; jump ...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…
... /> ld l,h
ld h,0
add hl,hl
ld de ... add a,(hl)
inc hl
ld h,(hl)
ld l,a
prtiv1: ld a,(de)
or (hl)
ld (hl),a
... l
ld a,(de)
or (hl)
ld (hl),a
...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), ...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 …
... hl, de
add hl, de
ld e, (hl)
inc hl
ld d, (hl ... )
ex de, hl
ld d ... /> 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 …
... ,L
LD L,A
LD A,(HL)
LD (DRAWB1+1),A ... ,L
LD L,A
LD A,(HL)
LD (DRAWE1+1),A ...Calculate screenaddressWho knows where the topic about the fastest screenaddressroutine is? I can't find it in a search.. The fastest routine was to load a large table of …
... * 256 = 64000
LD L,C
LD A,(HL) ; first part of ... H
LD H,(HL) ; Fetch Hi-byte
LD L,A
RET ; HL holds screenaddress
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 ... /> EX DE,HL
LD SP,HL
EX DE,HL
LD D,H ... /> 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 ...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…
... ,(HL)
LD (DE),A
INC HL
INC E
LD A,(HL ... )
LD (DE),A
INC HL ...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 ... 0 n-1
ld hl,(seed) ; fetch RND pointer ... br /> ld (seed),hl ; store next RND-pointer
ld a,(hl) ; ...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
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 ...Problem with rotating procedureHi folks! I wrote a proc in z80 asm, based on: x' = x * cos (z) - y * sin (z) y' = x * sin (z) + y * cos (z) I used a precalculated table of sin a…
... /> add hl,bc
ld e,(hl)
inc hl
ld d,(hl)
ld hl,(x ... /> add hl,bc
ld e,(hl)
inc hl
ld d,(hl)
ld hl,(y ... /> add hl,bc
ld e,(hl)
inc hl
ld d,…In Machine Code, what is the quickest way to sort bytes?I am playing around with some ordering of sprites, where I want to order them by vertical position. I used some Rodnay Zaks code to order some bytes…
... /> ld hl,numbers
ld bc,7
bubble ld (temp),hl ; temp = (hl)
again ld ix,(temp) ; ix ...
