-
Silent ROM Beeper Routine in SpinA new year -- a new idiot question! :) I've been playing around with Spectrum sounds of the old, beepy kind. When I wiggle[1] the speaker 'by hand' …
... ] ORG 25000
LD HL,400
LD DE,400
CALL $03B5 ... -
+3 assembler questionI was wondering if anyone could give any suggestions as to how to get this bit of code working on the +2A/+3 in 128k mode. It works on the +128k/+2 i…
... LIST_SP
LD A,(23622)
LD (23616),A
LD A,(23610 ... ;OSPCC - CONTINUE statement number
LD HL,(23641) ;E_LINE - address of editor ... in it
EX DE,HL
LD (HL),$e8 ;insert code for "CONTINUE ... -
Common pitfalls and solutionsLet's discuss some of the common problems in Speccy programming, and the methods we use to avoid them. For an example, here is a piece of code that …
... /> LD HL,#1BB0
PUSH HL
LD HL,(#5C4F)
LD DE,#000F
ADD HL,DE
LD DE ... ,#1B5E
EX DE,HL
LD ... -
Using the stack to copy memory blocksA [b]PUSH[/b] and a [b]POP[/b] instruction together take less time than two [b]LDI[/b], so long [b]POP/PUSH[/b] sequences are sometimes used to copy …
...
ld ix, source
ld hl, dest
ld de, 8 ; stepsize
ld a ... />
ld sp, hl ; 6
push hl ; 11
push de ; 11
Machine code issue...Hi Folks, My trials with MCODE continue and I am stuck. I wrote the following program in BASIC to simply POKE an attribute byte in to a "box" on th…
... LD DE,32
19 ADD HL,DE ;Add 32 to Address
ED5B03FA LD DE ... ,(64003) ;DE=Width
Optimization for this codeHello, I have done and submitted a small program for the CSS Crap Game Compo which involves a machine code routine. The z80 with BASIC and MC is av…
... /> main
ld hl, 16384
ld de, 160
add hl, de
ld a, (hl)
inc a
ld (hl),a
jr ... 0x1601
ld hl,text
loop ld a,(hl)
cp 255 ...Why doesn't my loop work?Can anyone help me understand why my loop doesn't work? Is it to do with how DEC HL affects the flags? [code] ; Read 32k bytes from port 191 as fa…
... to do with how DEC HL affects the flags?
LD HL,32767 ; Number of bytes to read
LD DE,32768 ; Destination ... A,(C)
LD (DE),A
INC DE
DEC HL
JR ...Why doesn't my routine work?I have a "level" defined by 504 bytes (28 squares across x 18 squares down) I'm trying to write a routine that will take an X,Y coordinate in pixels…
... />
add hl, de
ld de, (leveldata)
add hl, de ; ADD address of ...A fast DRAW routineI was investigating how to speed up the line drawing for the [URL="http://www.worldofspectrum.org/forums/showthread.php?t=20225"]BASIC compiler[/URL]…
... /> push hl
ex de, hl ; D,E = y2, x2;
ld a ... , (P_FLAG)
ld c ... 18h
ld h, a
ld de, (SCREEN_ADDR)
add hl, de ;; Final screen ...Back to BASIC[U][B]Archaeology guide to programs compiled used MCODERII.d[/B][/U] After various people have been talking about "Frank'n'stein" I decided to finis…
... finish off my MCoder II de-compilation notes to see if ...
+1 LD HL,0
+4 LD (59346),HL
+7 LD HL,LINES
+10 LD A,NVARS
+12 LD DE ...Shadow ROM partial decoding not implemented in emulatorsOr at least, not implemented in Spectaculator, and it seems that not in Fuse too. [URL="http://www.speccy.org/foro/viewtopic.php?f=8&t=408&start=53"…
... di
ld hl,StartCopy
ld (5cedh),hl
rst ... /> StartCopy ld hl,0
ld de,32768
ld bc,16384< ...(part of) screen to UDGHere is a routine to copy a Y,X-position on screen to a UDG. 0<=y<=23 0<=x<=31 144<=udg<=165 (UDG "A" to UDG "U") [code] ; start code with ; PRINT …
Here is a routine to copy a Y,X-position on screen to a UDG.
0Saving and Loading from tape in MC?I'm actually having problems with saving and loading from the ROM routines for the interpreter... I'm currently using the following codes for saving…
... /> [CODE]save:
ld ix, _tape_header
ld hl, _save_state
call 0x0970 ...
load:
scf
ld ... a, 0
ld ix, _tape_header
ld de, 17
automatic relocating of non-relocatable codeI was pondering upon the problem of changing absolute addresses used by CALL, JP, etc. when code is moved, without reassembling at the new location; …
... hl,bc
ex de,hl ;HL=address of location to change
ld (hl),e ;DE ... =new value
inc hl
ld (hl),d
Kiwi OS for z80 computerHi everyone, Nearly made my z80 computer with 2K ROM 32K RAM. It has an OS im still writing called Kiwi (apple, blackberry, you get the idea ;D) he…
... LENGTH
PUSH HL ;REMEMBER HL
LD HL, 1527 ;LOAD HL WITH ADDRESS STRING ... /> ;DE CONTAINS ACTUAL ADDRESS OF DATA
FILE_SAVE
LD HL, 8000 ... HL ;INCREMENT HL (NEXT ADDRESS)
INC DE ;INCREMENT NEXT MEM ADDRESS
LD ...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…
... 07
5B08 LD (5C48),A
5B0B LD HL,5800
5B0E ... ,5B11
5B1A LD IX,4000
5B1E LD DE,1B00
5B21 ... LD A,FF
5B23 ... ,5B1A
5B29 LD IX,5CB6
5B2D LD DE,A349
5B30 ...Keys redefine routine and key check.I have written some asm code which allows me to redefine keys (for a game etc.), and also allows me to be able to check any keypresses for the redefi…
... : ld de,0 ; DE will hold the bits for the keys pressed
ld hl ... /> dec hl ; go back to the key_xxx_port byte
ld a,(de) ; get ... the port that the key was found on
ld (hl ...Tile based graphics and scrolling thingy...Here's my best attempt so far at a tile based rendering and scrolling routine. It draws in 22 8*8 graphics tiles along the top of the screen (junk i…
... h
inc de
ld a,(de)
ld (hl),a
inc de
ld a,(de)
ld (hl),a
inc de
ld a,(de)
ld (hl),a ; ... draw last ...MCODE problem...Hi Folks, Trying to write a simple machine code program to hatch the screen. So far I have the following but even this is not working - it does not…
... LD HL,4000h
06 AA LD B,AA
11 01 00 LD DE ... ,100h
70 LD (HL),B
23 INC HL
1B DEC DE ...Getting the contents of tablesHi All, I'm risking a potentially daft question here as it seems pretty fundamental but here goes: What's the best way of pointing register pairs a…
... routine with hl pointing at a screen address and de at the ... [CODE] ld ix,blocktab
ld d,(ix+1)
ld e,(ix ... +0)
ld h,(ix+3 ... )
ld l,(ix+2 ... 'm basically longing for a ld hl,(ix) command!), I'm ...Lord Of The Rings; Files skipped ?Hi folks, Does anyone know what blocks 8~13 are for in the Lord of The Rings: [url]http://www.worldofspectrum.org/infoseekid.cgi?id=0006601[/url] I…
... ]
61440 LD HL,61440
61443 LD DE,23296
61446 LD BC,00144 ... RET
61660 LD HL,00000
61663 LD DE,00012
61666 CALL ... /> 61672 INC DE
61673 LD BC,00012
61676 LD (HL),000
AND,XOR,OR,BIT,RES,SET,CPL,NEG,RLC,RRC,SLA,SRL,RL, RR,SRA for BASICAs this was drifting away from the original INKEY$ thread I thought that I'd create a new one. So here's a routine to provide all of the above mentio…
... LOGIC: ld hl,12
add hl,sp
ld sp,hl ;undo USR ... ld hl,OPCODES
add hl,bc
add hl,bc
ld de ... bc
ld hl,OPERATE+1
ld a,(hl)
jr ...tiny routine to shift RAMTOP & stackCompressing some data areas above RAMTOP and wanting to make the released space available for BASIC arrays, I needed to move RAMTOP without using CLE…
...
TOPRAM: LD DE, (23730) ; 237 91 178 92
LD HL, 18 ; 33 ... 18 0
ADD HL, SP ; 57
LD SP, HL ...BREAK from GOSUBHere's another one. Just in case you wanted to break out of multiple GOSUB levels with a single command, here's a routine to do it, tested on all mod…
...
POP HL ; 225
POP DE ; 209
LD A, D ; ... ;restore (ERR_SP)
EX DE, HL ; 235
LD (23613), SP ; 237 115 ...Procrustean PrintingHere's a short routine to manage printing of text with command tokens, to avoid messing up the screen when they are expanded. It just prints as many …
... ;
STACK: ld hl,14
add hl,sp
ld sp,hl ;undo USR ... de,hl ;HL=string pointer
ld b,a ;B =max_length
SSNEXT1:ld a,(hl ...Indirect Variable AssignmentHere's another wacky routine. This allows assignment of values to variables where the source & destination variables can themselves be defined in var…
Here's another wacky routine. This allows assignment of values to variables where the source & destination variables can themselves be defined in variables (or expressions which evaluate to variables). Some of this can already be done with VAL or VAL$, ...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…
... a
sbc hl,de
inc hl
ld a,(hl) ;initial letter of ... array
dec hl
dec hl
ld de,3 ;DE=1 (name) + 2 ...A z88dk + sp1 demo (with source)Since nowadays people are still wondering about how difficult it is to make something in z88dk, I thought I just put a very simple demo to show how e…
Since nowadays people are still wondering about how difficult it is to make something in z88dk, I thought I just put a very simple demo to show how easy it actually is. (Actually I've already published this one some time ago, but this time the source is ...Loading the display with data from memoryTrying to load part of the screen(4k's worth) with data from memory location 53000, I've written this routine, but it doesnt work... [I]ld b,4000 ld…
... ]ld b,4000
ld de, 16384
ld hl, 55000
loop ld a,(hl)
ld (de ... ),a
inc de ...
inc hl ...S-S-Sample black borderI'm wanting the 'S-S-Sample' routine from YS to play the sounds without the flashing border effects. A plain black border is required. Heres the rou…
... /> ld hl, (32768 )
ld de, (32770)
ld bc, 2048
ld c, (hl)
ld a ... l_8047
inc hl
dec de
ld a, d
or ...
