-
Hi-Score tableThe score in my game occupies 3 bytes. I want to create a hi-score but I'm not sure of the best way to work out where a new score would fit in the ta…
... />
LD HL,4
ADD HL,DE
EX DE,HL
HL
ADD HL,BC
EX DE,HL
LD HL,NEWSCORE
Hi-Score tableThe score in my game occupies 3 bytes. I want to create a hi-score but I'm not sure of the best way to work out where a new score would fit in the ta…
Key press to ASCII valueI need a bit of code that will give me an ASCII value when the key is pressed. I only really need a-z. I tried using the following code but it only s…
... key pressed
ld hl,SPkeytranstbl
add hl,de
ld ...
ld e,40
add hl,de
.nocaps< ...
ld e,80
add hl,de
.nosym< ... entry
.SPtbllookup
add a,e
ld e ...Programming MC challengeIn the 80-ies I got the following assignment for a programming course. 2 16-bit values stored in #8000 and #8002 must be added together and stored i…
... /> LD DE,(&8002)
ADD HL,DE
JR NC,skip ... /> .skip
LD (&8002),HL
edit: Oh, ... />
Ok...
LD HL,(&8000)
LD DE ... )
LD A,L:ADD E:LD L,A
.skip
LD (&8002),HL
-- ...z88dk+splib2 sprites question.I'm creating a game and I have several "states" for my main sprite, such as jump, facing left, facing right, etcetera. All those states require a dif…
... hl,2
add hl,sp
ld a,(hl) ; a = N
inc hl ...
inc hl ... ,(hl)
inc hl
ld b,(hl) ; bc = colours
ex de,hl ; hl ...z88dk+splib2 sprites question.I'm creating a game and I have several "states" for my main sprite, such as jump, facing left, facing right, etcetera. All those states require a dif…
... a pucrunched file.
;## In : HL = source address
;## DE = destination ... /> inc hl
inc hl
inc hl
ld a, (hl) ; starting ... escape
inc hl ...z88dk+splib2 sprites question.I'm creating a game and I have several "states" for my main sprite, such as jump, facing left, facing right, etcetera. All those states require a dif…
... ', hl'
.SPHuffEncode
ld b,0
add hl,bc
add hl ... ,bc ; hl = &encoder[c ... on stack
ld hl,-3
add hl,de ; hl = parent
jp ...Machine Code: quicksort optimisationI came across this z80 quicksort implementation when going through the wikipedia article on the same. It's 44 bytes long. I was wondering if any of …
... HL = last item in array
.Lqsort
dec hl
add hl,hl ...
add hl,bc
; bc = left, hl = right< ... ; de = right
add hl,bc
rr h
Timex 80 column display driverI subsequently wrote an 80 column font driver for 512x192 mode.
... /> add hl,hl
add hl,hl
add hl,hl
ld de,font-100
add hl,de ...
ex de,hl ... print routine
ld hl,(nextdfile) ; hl = destination dfile address
Timex 80 column display driverI subsequently wrote an 80 column font driver for 512x192 mode.
You can still save a few cycles in all instances of ADD HL,BC where C is loaded with zero by using 8 bit additions via A.
LD BC,xx00 : ADD HL,BC = 21 cycles.
LD A,H : ADD A,xx : LD H,A = 15 cycles.MEMPTR finally crackedThis post is mainly for emulator developers. As you may be well know there is a misterious internal register in Z80 CPU (MEMPTR) which value is set …
... . This includes the instructions ADC, ADD, SBC, INC, DEC but not ... . I have been using the ADD HL,DE instruction to test. The ...Shoot-em-up Development UpdateHi Folks, I am still working away at my horizontal scroller. Here is a link to let you see progress. I have re-written the scrolling routine to make…
...
ADD A,A
ADD A,A
ADD A,B ... New] ADD A,A
ADD A,A
ADD A,A ... /> [FONT=Courier New]NEXTROW EXX: ADD HL,BC: EXX[/FONT]
[FONT ...Key press to ASCII valueI need a bit of code that will give me an ASCII value when the key is pressed. I only really need a-z. I tried using the following code but it only s…
... key pressed
ld hl,KeyTransTables
add hl,de
ld e,40
add hl,de
NoCaps ... /> ld e,80
add hl,de
NoSym ...Key press to ASCII valueI need a bit of code that will give me an ASCII value when the key is pressed. I only really need a-z. I tried using the following code but it only s…
...
ld e,80
add hl,de
[/code]
[/QUOTE ...
ld e,80
add hl,de
[/code]
Checksum RoutinesHi there everybody, Does anyone have an 'off the shelf' assembler routine for generating checksums? Thanks Jim
... =number of bytes
;Outputs: hl=CRC16
push bc ;Loading schemes18 years ago I hated loading schemes like Alcatraz and Speedlock because they were a b*tch to copy and became unreliable when the tape got older. Now…
... I have been trying to add some great loaders that ... hl,23296
ld (hil),hl
ld hl,20704
ld (dil),hl ... /> add hl,hl
add hl,hl
add hl,hl
ld de,39744
add hl,de< ...Self Relocating CodeOn page 47 of [url]http://www.tim-mann.org/trs80/doc/ldosq1-3.txt[/url] is an article about relocating code. The documented routine that performs the…
... Speccy
LD HL,RELTAB
ADD HL,BC ; BC is start ... D,0
EX DE,HL
ADD HL,BC
LOOP LD ... A,C
ADD A,(HL)
LD (HL ...Pixel Explosion CodeJust a little snippet to cause explosive effects. It uses table lookups for the screen address, and can handle up to 32 pixel particles. A particle…
... /> inc hl
ld b,(hl)
inc hl
ld c,(hl) ; bc ... ; a = old x coord
add hl,bc
sub h ; subtract ... /> ld l,(hl)
ld h,a ; hl = dy
add hl,bc
Spectrum Screen Memory MapWhat's the advantage (mistery?) behind ULA's spectrum screen memory interpretation? 6144 bytes divided into 3 blocks, 2048 bytes long. if you want t…
... we could just use INC HL in the 32nd increment to ... (compare famous DOWNHL with simple ADD HL,BC) or using lookup tables ...Oh so BRIGHT!What is the SLOWEST way to change the attribute area to BRIGHT? It has to be legit! No meaningless instructions or doing stuff for the sake of it. …
... ld iy,0
add iy,sp
... de,1
add hl,de
ld de ... /> sbc hl,de
add hl,de
push hl
...Urgent Help needed to fix this: calling all machine code gurusI am currently trying to write tutorials on the amazing Orfeus music composer by Proxima which allows you to do multi channel music through the beepe…
...
add a,(hl)
add a,(hl)
add a,(hl)
add a,(hl)
add a ...
add a,(hl)
add a,(hl)
add a,(hl)
add a,(hl)
add a ...ZXSpin 0.61 Available nowHi all! Well, after a lengthy few testing cycles, I'm taking the plunge and uploading the latest version of ZXSpin, to replace the rather aged old 0…
According to the [URL=http://www.mdfs.net/Software/Z80/Exerciser/Spectrum/]Z80 Exerciser[/URL], some flags are wrong.
The failed tests are:
hl,
add hl,
add ix,
add iy,
bit n,ZXSpin 0.61 Available nowHi all! Well, after a lengthy few testing cycles, I'm taking the plunge and uploading the latest version of ZXSpin, to replace the rather aged old 0…
... tests are:
hl,
add hl,
add ix,
add iy,
bit ...Help understanding some z80 asmI'm trying to work out how to represent the structure of a "sprite" in the SAM as "Grabbed" by SmallC. I can see the assembler implementation but I …
... ld hl,4
add hl,sp
ld c,(hl)
inc hl
ld b,(hl)< ... is then loaded into HL before leaving the function. ... values are received in the HL register.
... is much quicker if HL is used to step ...Wanted: z80 asm routines...for the Sam. This call goes out to Colin and others who know how it should be done. If you look on the Sam C disk you can see the implementation…
... hl,4
add hl,sp
ld a,(hl)
dec hl ...
ld d,(hl ... )
dec hl
ld e,(hl ... /> ; put return value into HL (perhaps success/fail)
< ...Cybernoid editorSo, my long tern goal is to make my own Cybernoid or Rex like game (see an ancient thread about Sprite advice)...but my skills are somewhat lacking..…
... $6ec6
ex de,hl
pop hl
ld a,(de ... 3
ld (hl),c
$3: inc hl
inc de ... 4
ld (hl),c
$4: inc hl
inc de ... /> $5: ld de,30
add hl,de
djnz $2
pop hl
pop de
pop ...My little first set of routines.Hi all, I just coded a little set of routines just to draw a screen on video mem and a fade out. I could have just copied the screen rendering rout…
... push de
push hl
ld ... />
ex de,hl
ld bc,32 ... ex de,hl
add hl,bc
ex de,hl
... ex de,hl; add hl,bc; ex de,hl". Edit: ...My little first set of routines.Hi all, I just coded a little set of routines just to draw a screen on video mem and a fade out. I could have just copied the screen rendering rout…
... 8 cycles when the equivalent "add a,a" only takes 4 ... -bit shifts, keep in mind "add hl,hl" which does it in 11 ... the much less attractive "adc hl,hl" which does it using the ... 15 cycles. "adc hl,rp", like "sbc hl,rp", are a couple ...Disassemblers and RSTsI think this is a longshot, but... is anybody aware of a disassembler that handles the Interface One RSTs? e.g. RST $10 DEFW $0020. Cheers
... 11 2c 00 $0ats
add hl, de ; f98d 19 $0bts ... f9fe e6 1f $07ts
add a, $60 ; fa00 c6 ... $11ts
l_fa4a: inc hl ; fa4a 23 $06ts
... $0ats
l_fa4e: push hl ; fa4e e5 $0bts
... fa5b c1 $0ats
pop hl ; fa5c e1 $0ats
...
