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Machine Code Routine of the weekHow about a thread that has a routine each week that is in [B]assembly language[/B] and is also described in great detail what the hell is going on …
... mean a ld bc,word at the beginning, so 20 bytes. I ... -
Machine Code Routine of the weekHow about a thread that has a routine each week that is in [B]assembly language[/B] and is also described in great detail what the hell is going on …
... mean a ld bc,word at the beginning, so 20 bytes. I ... -
Machine Code Routine of the weekHow about a thread that has a routine each week that is in [B]assembly language[/B] and is also described in great detail what the hell is going on …
... QUOTE=antoniovillena;640512]16 bytes. Now we have ... $7848
ld hl, $5b00
loop0 ld a, (bc)< ... br /> and l
ld (hl), b
jp ... pe, loop1
ld (hl), c
loop1 ... -
Saving space using procedural graphicsAfter spending several hours playing around with various packers to squash the Alien8 test screen$ it occured to me that maybe bigger space savings c…
... UP
616 bytes of data at 41000[/QUOTE ... 40000
ld hl,23295
l40003: ld (hl),69
ld de,a8data
ld b,0
... call l40033
ld ixl,41
l40021: ... br />
l40033: ld ixl,43
l40036: call ... -
64x48 full colour graphicsHow feasible is this? Could an interrupt-driven routine be used to, for example, fill the top two thirds with a 64x32 blocky picture and leave the bo…
... .
So
LD HL,NN ;10
PUSH ... copied. Copying one line=32 bytes would need 336 tstates.
64x48 full colour graphicsHow feasible is this? Could an interrupt-driven routine be used to, for example, fill the top two thirds with a 64x32 blocky picture and leave the bo…
... from the source data then LD (NN),HL, which as a ... use it to write some bytes from left-to-right instead ... a big gain by using LD instead of POP to fetch ...64x48 full colour graphicsHow feasible is this? Could an interrupt-driven routine be used to, for example, fill the top two thirds with a 64x32 blocky picture and leave the bo…
... /> I see you've used LD (HL),n followed by INC ... use LD HL,nn and LD (nn),HL to do two bytes at ...64x48 full colour graphicsHow feasible is this? Could an interrupt-driven routine be used to, for example, fill the top two thirds with a 64x32 blocky picture and leave the bo…
... /> I see you've used LD (HL),n followed by INC ... use LD HL,nn and LD (nn),HL to do two bytes at ... /> You're right.
LD (HL),N
INC HL ...
LD (HL),N
INC HL ... too.
LD HL,NN
LD (NN),HL is just ...64x48 full colour graphicsHow feasible is this? Could an interrupt-driven routine be used to, for example, fill the top two thirds with a 64x32 blocky picture and leave the bo…
...
LD (MV10+2),HL ;IX,IY instructions take 4 bytes, not ... 3
POP HL
LD (MV11+2 ... /> LD HL,22528
LD (CurrentLineStart),HL
LD HL,AttrBuffer2
LD ...Switching 48/128 modes within a BASIC programI'm not sure what use this would be; ie. being able to switch between 48k and 128k modes and back again from within a continuously running BASIC prog…
... working. It's about 30 bytes longer than Toggler, but ModeSwap ... =channel info for "P"
ld bc,$0004
ldir ;replace ... "S"
TO_ALL: ld sp,($5c3d) ;ERR_SP
ld hl,$0014 ;address ...Switching 48/128 modes within a BASIC programI'm not sure what use this would be; ie. being able to switch between 48k and 128k modes and back again from within a continuously running BASIC prog…
... ;642599]It's about 30 bytes longer than Toggler[/QUOTE]
ret z ;16k/48k
ld a,(iy+$01)
bit ... BASIC" mode
ld sp,($5c3d) ;ERR_SP
ld hl,$0014 ;address ...DooM on Spectrum 128kHello my fellow WoS'ers My hope is that you can help me, recently I discovered a DooM clone -esque on the Humble spectrum, - here is a [URL="https:/…
... shifted the stack by three bytes so I was patching it ... /> ld hl,get
ld ($618d),hl
ld hl,23296
ld de ... ,saved
getput: ld ...assembly optimization: times tenDecimal numbers are not computer friendly :) Anyway, short of saying "sod it - I'll multiply by 8" - and another part of the program does indeed div…
... t-states) - but wasting 512 bytes to save a 23 t ... -states...
[code]
LD H, lookup / 256 ; 7
LD A,(HL) ; 7
INC ... L ; 4
LD H,(HL) ; 7
LD L,A ; 4 ...assembly optimization: times tenDecimal numbers are not computer friendly :) Anyway, short of saying "sod it - I'll multiply by 8" - and another part of the program does indeed div…
... t-states) - but wasting 512 bytes to save a 23 t ... states...
[code]
LD H, lookup / 256 ; 7
[code]
LD H, lookupMSB / 256 ; 7
LD H,(HL) ; 7
LD A,(DE) ; 7 ...
LD L,A ; 4 ...Work out attribute location in MCHow do I go about writing a MC routine which calculates the attribute address from a set of PRINT co-ordinates. I know you in basic you multiply the…
... ) reads TWO bytes from 60000 and 60001, as LD DE,(60001) does ... adding different values.
LD HL,(60000) in your program ... />
Try [B]ld a,(60000); ld h,0; ld l,a[/B ...Work out attribute location in MCHow do I go about writing a MC routine which calculates the attribute address from a set of PRINT co-ordinates. I know you in basic you multiply the…
... aligned on a 256-bytes boundary, first 24 bytes of the table ... L=Y
ld a,h
ld h,table/256
ld d,(hl)
... br /> add a,(hl)
ld e,a[/code]
bytes boundary. Then you can ...Quickest way to fill the attributes using LDIRI'm looking for a small routine to fill the entire attribute area of the memory with a single value, I've used LDIR in the past, but forgotten how to…
...
BC = the number of bytes to copy
So ... the value you want using LD (HL),ATTR_VAL) to the very ... . And we're copying 767 bytes.
Seemples ...40 Column Printing RoutineI've written a 40 column printing routine, which I'd like to share... It's my first piece of 'public' code so go easy on me! I don't think it is a…
... /> org 65121 ; 415 bytes
c_chan:
ld hl, (prog) ; a ...
ld bc, 5 ; the new channel takes 5 bytes
call ... address
ld bc, do_it ; could write the bytes directly but
40 Column Printing RoutineI've written a 40 column printing routine, which I'd like to share... It's my first piece of 'public' code so go easy on me! I don't think it is a…
... br /> ; POKEable flags, 6 bytes
;----------------------------------------------------------------------------
overflag defb ... ld a,(xcoord)
ld d,0
ld e,a
ld ...Quickest way to fill the attributes using LDIRI'm looking for a small routine to fill the entire attribute area of the memory with a single value, I've used LDIR in the past, but forgotten how to…
... with SP?
[CODE]ld hl,#0000
push hl ... hl,sp
ld sp,#5b00
ld b,#c0
loop ... , loop
ld sp,hl
ret[/CODE]
17 bytes?merging bytesPicturing three bytes with their bits identified by letters to make the visualisation easier, what's the best way to perform this transformation? [co…
... [*] OR the separate parts with bytes 1 and 2
[/list ... /> ; Breaks: A, D
LD A, H
AND E0h ...
LD H, A
LD A, L
LD L, A
LD A, D
RRCA
RRCA
LD D, A
...WibbleBibble's Basic threadHi in an attempt to keep my questions from spamming the forum. I think its better to put them all in one place. Thanks everyone so far, I feel I am …
...
pokeink:ld bc,21*32
ld hl,(23639) ; ... push bc
ld b,0
ld c,a ;BC= ... ;A =INK colour
ld hl,22527
pop bc ... />
Also, 21*32 bytes could be saved by printing ...Xor-shift random number generator for Z80[QUOTE=Patrik Rak;320244]Come on, people, [URL="http://www.jstatsoft.org/v08/i14/paper"]xor-shift generators[/URL] devised by Marsaglia, that's the w…
... I was counting the bytes/cycles, but didn't ... br /> [code]
rnd ld hl,0xA280 ; yw -> zt ...
ld de,0xC0DE ; xz -> ... yw
ld (rnd+4),hl ; x = ... br /> xor l
ld h,e ; y = ...Tutorial - learn machine code in 30mins[B][I]Message from the moderators[/I] - bigjon has requested that readers' attention be drawn to a better version of this tutorial, one which is easi…
... Spectrum Manual.
Some instruction bytes, like 201 for 'ret', ... ld bc is 1. The computer then expects 2 data bytes ... do 'ld a, 0' but this takes 2 bytes whereas ' ... of random bytes in ROM
ld d,0
ld e, ... of random bytes in ROM
ld d,0
ld e, ...Mini scroll routineI'm looking for a routine that scrolls a small section of the screen downwards and replaces it with nothing, 2 x 2 charcter blocks to be precise, to …
... whole display file in 88 bytes. (The first part just ...
;
scroll_whole_screen_down_by_one_line
ld hl,22240 ;point hl at ... br /> scroll_one_line
ld d,h
ld e,l ;point DE ...
;
drawline
ld bc,32
ldir
Help needed...I am at my wits end with this pigs ear of a routine, can anyone simplify it and make it work as it should? Basically it should make the characters '…
... on it
;
ld a,(number_of_repeats) ;can be catered ... call print_string ;prints OFF
ld a,(xcor)
add a ... br /> ;
print_string
ld a,22 ;print AT
ld bc,4 ;length of string in bytes
...help needed :) how to rotate a 3 x 3 array 90 degreesI just cant seem to get this sorted in my head ( or on paper ) , I've found multiple examples in C , python , etc but cant find any z80 examples any …
... you have a string of bytes:
[B]A1 ... />
[CODE]LD HL,Source
LD DE,Destination
LD BC,6 ... to c1
LD A,(HL) ;copy c1
INC DE
LD A,(HL) ;copy b1
INC DE
LD A,(HL) ;copy a1
