-
Converting an integer arbitrary large binary number into a printable decimal formThis was asked a long ago at the comp.sys.sinclair newsgroup. At that time, I came up with a solution by extrapolating the classic algorithm of suces…
... /> Add4Block proc
ld hl,BCD
BucAdd ld a,(hl)
cp 50h ... leading zeros
ld hl,BCD
BucPrint2Dig ld a,(hl)
srl a ... -
About how z88dk generates code and makes room for variables.When you attempt to code games for the 128K models using z88dk in C you need to somewhat control where variables are stored in memory. I thought tha…
... />
[code]ld A, $06
ld ($5EF1), A
ld A, $07 ...
ld ($5EF2), A
ld HL, $0008
ld ($C729), HL
ld HL ... , $0009
ld ($C77D), HL ... -
Ghosts n' Goblins loaderI'm trying to put Ghosts n' Goblins onto a +3 disk but struggling to understand the mc loader. Basic loader [code] ink 7 : clear 25000 : load "" cod…
... : LD SP, HL
65253: POP HL
65254: LD SP, HL
65255: LD HL, 60016 ...
65258: PUSH HL
65259: PUSH HL ... -
Scrolling Bi-Colour Engine for 4-Player GamesJust putting this code up for people to have a look at. Far from finished. Should simply compile and run a bit of a demo. Only good for 128K and +…
...
ld hl,48640
ld de,48641
ld (hl),191
ld bc,256 ... /> ld hl,char_address
add hl,bc ;hl = row in table
ld e,(hl)
inc hl
ld d,(hl ... -
Does this addressing technique have a name?Hi All, Bit of a weird/unnecessary question, but can anyone help build on my knowledge of asm terminology by telling me what the *second* method of …
... ,21
LD (PlyrY), A
LD A,15
LD (PlyrX), A ... Method:
LD HL, 3861
LD (PlyrY), HL
DEFB:
understanding machine codeHi Quick question. Am not really sure if it fits development forum as its not really development per se its more a learners question about developm…
... POP HL
7E LD A,(HL)
23 INC HL
E5 PUSH HL
323C5C LD (TVFLAG),A
... using Zero emulator)
323c5c LD (TVFLAG), A
LD (TVFLAG), A
< ...SBC or ADDIs this dangerous/bad practice thing to do..... I want to subtract 64 from a number, but to save a few bytes can I just add (65536-64) 65472 to the…
... LD HL,32768
LD BC,65472
ADD HL,BC
LD (test),HL
LD HL,32768
LD BC,64
SBC ... HL,BC
CCF ; ... sometimes it need this....
LD (test),HL
RET
Currah ?Speech channelIt seems to me that it would be nice to be able to send words to the ?Speech with PRINT #5;"Speak English to me, Jimmy" or some such. There really i…
... /> new_word:
ld hl, 65362 ; if zero
ld (hl), $51 ; make it ... add hl, de ; allophone
ld a, (hl) ; get allophone
ld hl, ( ... 65362) ; address buffer
ld (hl), ...Hooky - hook ZX ROM and rewire RST and NMI to RAM - rantThis is a rather long rant. Not for short tempered. :) The objective is to hook into RST "vectors" and NMI on a Spectrum without affecting the normal…
... /> 0x11DC LD (HL),#0x02 ; mem. 0xffff is 2
0x11DE DEC HL ; HL=HL-1 ... 5cb2
0x1222 LD HL,(5CB2) ; FF57
0x1225 LD (HL),#0x3e ; write 3e ...
0x1227 DEC HL ; hl=ff56
0x1228 LD SP,HL ; setting sys. stack ...Help with Manic Miner tweaksPlease. :) This is the Software Projects version, simply as I had it to hand. [B]Problem 1:[/B] I've learned a bit (actually quite a bit) and manag…
... 37107 24 202
L_90F5: LD (HL), 48 ; 37109 54 48
DEC HL ; 37111 43
LD A, L ; 37112 ... 50 87 132
L_9109: LD A, (HL) ; 37129 126
... :
[code]L_8FD0: LD HL, (L32944) ; 36816 42 176 128 ...Problem Reading the KeyboardHi Folks, I'm working my way through Toni Baker's rather good book and thought I'd write some code to scan the keyboard and store the results so tha…
... copy
LD DE,_oldKeyStates ;Destination
LD HL,_currentKeyStates ;Source< ... the keyboard segments
LD HL,_currentKeyStates ;Where to store ... keyboard segment number
LD HL,_keyboardSegments ;Calculate the keyboard ...Better arrangement for video memory?While doing some documentation work for the ZX-Uno project, I compared the advantages of the weird layout of the ZX Spectrum against a linear layout.…
... ,8
BucScan:
ld a,(hl)
ld (de),a
inc ... .
;OUTPUT: HL=address of byte containing pixel
LD B,A ... ,8
BucScan:
ld a,(hl)
ld (de),a
inc ...Help needed with a bit of code...My minds gone blank again I'm afraid, I'm having trouble with this routine that loads variables into memory then calls the corresponding routine. Th…
... ld b,3
ld hl, cor
ld de,adds
loop
ld ... a,(de)
ld ... inc de
ld a,(de)
ld (caller+2),a; loads ... inc de
;ld a,(hl) ;hl stores variables
;now i ...Double height text...<p>Is here any good routines for printing a font double height?</p><p>I've concocted this ridiculous routine but I'm sure it can be done much better.…
... (hl)
ld hl,x12+1
inc (hl) ld hl,x13+1
inc (hl) ld hl ... ,x14+1
inc (hl) ld hl,x15 ... +1
inc (hl); ld hl,x16 ...Drawing some spritesI figured I want to draw some sprites. My target was to do a 16x16 masked sprite. There's no clearing here, just drawing the sprites. My first ite…
...
and (hl)
inc hl
or (hl)
ld (de),a
and (hl)
inc hl
or (hl)
ld (de),a
Mr. Jido makes some noiseA little something to analyse and discuss for you. [code] ORG 60000 ; RND Generator: RND LD HL,EARTH LD A,(WIND) ADD A,L LD …
... ,(HL)
LD (FIRE),A
LD HL,WIND
INC (HL)
LD E,(HL)
LD HL ... ,EARTH
ADD HL,DE
LD A,(HL)
LD ...Text scroller and custom fontYesterday I was testing this text scroll routine taken from Jonathan Cauldwell's Intro Maker (labels have been inserted to allow partial code relocab…
...
LD HL, FONT
LD (23606),HL
LD DE,L_35413
LD BC,00001 ... L_35420
LD HL,(L_35489)
LD A,(HL)
POP HL
... LD HL,PUNTO_A
RRC (HL)
RET NC
LD HL,(L_35489)
INC HL ...Simple bit of machine code not working [SOLVED]ishHi all. It's late and I'm tired and I have no idea why the following piece of code wont display a little smiley face [code]ld hl,udg ld (236…
... />
[code]ld hl,udg
ld (23675),hl
ld a,2
call 5633
ld a ...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…
... pop de
pop hl
ld sp, #(constant value of scanline ... #12
add hl, bc
ld sp, hl
pop af < ... pop de
pop hl
ld sp, #(constant value of scanline ...Faster Manic MinerHey, dudes. I've been fiddling around trying to wring more speed out of this game recently. I've replaced the LDIR buffer copying routines with s…
... buffer and an unrolled POP HL, LD (nn),HL section for the 512 ... stick another enormous unrolled POP HL, LD (nn),HL section. That should give ...ZX Spin and a question or two......Not really used Spin before since Spectaculator covers everything I need - except now I have need of an easy to use assembler. Downloaded several, n…
... />
[code]
LOOP LD A,(HL)
CP 0
JR ...
RST #10
INC HL
JR LOOP
[/code ...Code optimisation! 16bit number to 5 digit stringJust for interest this one, any thoughts on how to make this as fast as possible? Little optimisations to this routine or a complete reimagining? …
... number2string: ;arrive DE number, HL at end of string,assume ... lp: inc (hl) ;increase string number
ld a,(hl)
... jp c,cont
ld (hl),'0' ;yep,reset and ...
cont: ld l,c ;HL back to start of ... number counter
ld a,d
or ...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…
... number. This version returns with HL holding a 16-bit random ... ,$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 ... hl
loop1: ld a,(hl) ; get pixel
ld ... /> saveaa: ld hl,0 ; retrieve ...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…
... two sprites, hence the [b]ld hl,(sprite_8x8[/b]) instruction.)
... DE
ld hl,(sprite_8x8) ;point HL to sprite data
ld (hl),a ;place it on screen ... right
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 ... :
PUSH AF
LD A,(HL)
LD (DE),A
ADD ... HL, BC
POP AF
ZXSCLZF - Yet another Screen CompressorQuick disclaimer before I continue, this compressor does not shrink screens as small as some of the others posted here, in particular the very good z…
... ;; ==============================================
org $c000
ld hl,screen ; 10t - start location of ...
ld e,(hl) ; 7t
inc hl ; 6t
ld d,(hl) ; 7t - ... br /> _ulzfa040:
ld a,(hl) ; 7t
ld (de),a ; 7t ...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,(SCORE)
LD (FOURTH),HL
LD HL,POS_4+3
LD (TEMP),HL
LD HL,(SCORE)
LD (SECOND),HL
LD HL,POS_2+3
LD (TEMP),HL
