-
Tile routinesHi all, Please does anyone have any examples of tile routines in pure asm to set up maptile screens. I would like to try and understand them and ti…
... :
ld a,(de)
ld (hl),a
inc h
ld a,(de)
ld (hl),a ; print the colour
ld a,b
sra a
sra a
sra a
add a,88 ... -
Tile routinesHi all, Please does anyone have any examples of tile routines in pure asm to set up maptile screens. I would like to try and understand them and ti…
... :
ld a,(de)
ld (hl),a
inc h
ld a,(de)
ld (hl),a ; print the colour
ld a,b
sra a
sra a
sra a
add a,88 ... -
Questions about Vortex Tracker II exported songsHi, I have been experimenting with Vortex Tracker II lately and have a couple of questions. By exporting the song to TAP format, a file is generated…
... e. which lines should I add to it? (Please note that ... #fe00
ld hl,#fe00
ld a,h
ld ... /> im 2
dec a
ld (hl),a
inc l
inc h
ld (hl),a
;make interrupt executor
push af,hl,de,bc,af
... -
writing incrementally to tape without leadersI want to be able to write intermittently & incrementally to some sequential medium which is supported on any Spectrum (emulator, ie. tape); eg. [cod…
... H,0
ADD HL,DE
LD (HL),A
INC L
LD (OFFSET),HL
RET ... /> LD DE,15
ADD HL,DE ; HL=>'P' output address
HL
LD (HL),D
RESET
XOR A
LD (OFFSET),A ... -
ZX Alien BreedNot sure if this has been mentioned already (I did trawl the threads but couldn't see anything :smile: ), but I've always hankered after a Speccy Ali…
... a look :-)
[CODE]drawsprite:
ld hl,(sprloc) ;Load HL ... height
ld a,(sprwide) ;Load counter ... ld a,(de) ;load A with sprite byte
ld (hl),a ...
add hl,de ;Add 30 to HL to start ... -
Routine for handling large scores?[FONT=Calibri][SIZE=3]I want to store various numbers for scores and levels etc. Some of these can be very large so will need to be held in multiple …
... ld b, 0
add a, (hl)
ld (hl), a
cp 10
ld (hl), a
dec hl
ld a, b
jp ... -
Routine for handling large scores?[FONT=Calibri][SIZE=3]I want to store various numbers for scores and levels etc. Some of these can be very large so will need to be held in multiple …
... altered something I found in a game!) about 25 years ... find it I'll plonk a link to the image ... . It just took a value in a 16 bit register and ... added it to a series of bytes (from ... 07 (representing 21087)
Add HL=001A (26)
... -
Routine for handling large scores?[FONT=Calibri][SIZE=3]I want to store various numbers for scores and levels etc. Some of these can be very large so will need to be held in multiple …
... ld a,(hl) ; current value of digit.
add a,b ; add points ... to this digit.
ld (hl),a ; ... subtract 10.
ld (hl),a ; put new character back ... -
Routine for handling large scores?[FONT=Calibri][SIZE=3]I want to store various numbers for scores and levels etc. Some of these can be very large so will need to be held in multiple …
... A ;find digit
SBC HL,DE
JR NC,TypeScoreDigit11
ADD HL ... ,DE
DEC A
... EXX
PUSH HL ;store ... CALL TypeNumber
POP HL
INC L ;screen ... -
Routine for handling large scores?[FONT=Calibri][SIZE=3]I want to store various numbers for scores and levels etc. Some of these can be very large so will need to be held in multiple …
... A ;find digit
SBC HL,DE
JR NC,TypeScoreDigit11
ADD HL ... ,DE
DEC A
... EXX
PUSH HL ;store ... CALL TypeNumber
POP HL
INC L ;screen ... -
Multiply by 48Is there a 'cheat' to multiply by 48 in Z80? I have a table of sprites 48 bytes each entry, and I want to be able to offset my pointer with a simpl…
... ;
[CODE] ld a,number
add a,a
ld h,0 ... /> ld l,a
ld de,table
add hl,de
ld ... e,(hl)
inc hl
ld ... -
Multiply by 48Is there a 'cheat' to multiply by 48 in Z80? I have a table of sprites 48 bytes each entry, and I want to be able to offset my pointer with a simpl…
catmeows, cool!
ld a,num sprite
ld l,a
ld h,0
add hl, hl ;x2
add hl, hl ;x4
add hl, hl ;x8
add hl, hl ;x16
push hl
add hl, hl ;x32
pop de
add hl, de ;x48 -
Multiply by 48Is there a 'cheat' to multiply by 48 in Z80? I have a table of sprites 48 bytes each entry, and I want to be able to offset my pointer with a simpl…
... L,A ;put sprite no. into HL
ld H,$00 ;
add HL,HL ... ;x 2
add HL,HL ;x 4
add HL,HL ;x 8
add HL,HL ;x ... ;
add HL,HL ;x 32
add HL,BC ;add (HL x 16)
… -
JP (HL) confusionokay.... JP nn will jump to memory address nn. JP (HL) ,I assumed would read the contents of memory address HL and jump to the location and be a gre…
... a waste of instruction set space to have both ADD HL, ... SP and LD HL,SP, although you ... and the i8080 only had ADD HL,SP, which it named ' ... DAD SP' (Double-byte ADd Stack Pointer). This does follow ... IY before doing 'ADD IX,SP' or 'ADD IY,SP', ... -
Multiply by 48Is there a 'cheat' to multiply by 48 in Z80? I have a table of sprites 48 bytes each entry, and I want to be able to offset my pointer with a simpl…
[QUOTE=Atari_Jetman;759633]Is there a 'cheat' to multiply by 48 ... /> ADD HL,DE ; *2+1 = *3
ADD HL,HL ; *6
ADD HL,HL ; *12
ADD HL,HL ; *24 ...
ADD HL,HL ; *48 -
Multiply by 48Is there a 'cheat' to multiply by 48 in Z80? I have a table of sprites 48 bytes each entry, and I want to be able to offset my pointer with a simpl…
... = a
add hl, hl ; hl = 2a
add hl, de ; hl = 3a
add hl, hl ; hl = 6a
add hl, hl ; hl = 12a
add hl, hl ; hl ... -
JP (HL) confusionokay.... JP nn will jump to memory address nn. JP (HL) ,I assumed would read the contents of memory address HL and jump to the location and be a gre…
... a kind of next value - so have to add 2x INC HL ... correct tile type
LD A,(HL) ; A store 'L' of jumptable ... /> LD L,A ; flip A to L
JP (HL) ; do the ... -
JP (HL) confusionokay.... JP nn will jump to memory address nn. JP (HL) ,I assumed would read the contents of memory address HL and jump to the location and be a gre…
... /> LD hl, 0 ;make hl zero
LD l,a ;hl = a
ADD hl,hl ;double hl, as ... lookup uses 16-bit values
ADD hl,de ;hl ... -
128+2 Help!Today the postie brought me an early Spectrum 128+2, it's a Z70700 Issue 1. Everything seems to be working ok, i.e it boots up and the keyboard work…
... L_802A: LD (HL), A ; 32810 119
ADD HL, DE ; 32811 ...
ADD HL, DE ; 32896 25
LD A, 104 ; ... 62 104
LD (HL), A ; 32899 119
... -
Clashbasher a new interface to reduce colour clashI've been working on this for a while now. [IMG]http://markamy.uwclub.net/cauldron.JPG[/IMG] Basicly its an add on for a 48k spectrum, which reinte…
... and work out where to add more clashbasher instructions.
HL)-----changed to ----- LD (HL),0
#B138 LD (HL),A
a sna file but it should be simple to add it ... to the game with a few pokes ... -
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…
... your question: I use ADD when subtracting a constant
... [code]
ld de, -const
add hl ... , de
[/code]
while subtracting a variable ... ld de, (var)
or a
sbc hl, de
[/code] -
Column and row numbers to attr address?[FONT=Calibri][SIZE=3]Can anyone provide me with a code snippet the will convert the column and row numbers into the screen attribute address. For ex…
[CODE] ld a,e
add a,a
add a,a
add a,a
ld hl,22528/4
ld l,a
add hl,hl
add hl,hl
ld a,l
or ... -
Column and row numbers to attr address?[FONT=Calibri][SIZE=3]Can anyone provide me with a code snippet the will convert the column and row numbers into the screen attribute address. For ex…
... Output: HL=attr address
Modifies: HL,DE,A
... [code]ld h,0
ld l,d
add hl,hl ...
add hl,hl
add hl,hl
add hl,hl
add hl,hl
... ld e,d
ld d,58h
add hl ... -
Column and row numbers to attr address?[FONT=Calibri][SIZE=3]Can anyone provide me with a code snippet the will convert the column and row numbers into the screen attribute address. For ex…
... ][CODE] ld a,e
add a,a
add a,a
add a,a
ld hl,22528/4 ...
ld l,a
add hl,hl
add hl,hl
ld a,l
or ... -
Spectrum screen layoutSeeing the thread on displacement I was wondering why the spectrum had the stupid screen split into three sections and the addresses for each section…
... next pixel line within a character square by adding ... /> LD A,L
ADD A,32
LD L,A
... RET NC
LD A, ... I'd really prefer [B]ADD HL,DE[/B] in any case ... practically every game that uses a backbuffer has it organized in ... -
Spectrum screen layoutSeeing the thread on displacement I was wondering why the spectrum had the stupid screen split into three sections and the addresses for each section…
... did easy stuff like typing a letter even more easier ... the non-linear one requires a lot more thought behind ... it was probably quite a good idea if text ... about.
Even "ADD HL,DE" is not as good ... it seems. You have a register pair dedicated to the ... -
Sorting BusinessThis is a little bit different from the usual game-related fare but I know there are a few people here who like this sort of thing. This is about so…
... purposes. You cannot make a copy of the pivot element ... the first division with a largest power of 2 ... ; carry reset
; select a random pivot @ address k
add hl,de ; hl = k - k % size + i< ... -
Sorting BusinessThis is a little bit different from the usual game-related fare but I know there are a few people here who like this sort of thing. This is about so…
... />
or a
sbc hl,bc ; hl = j-1
hl ; hl = array_lo
push hl
or a
sbc hl ...
pop hl ; hl = i
add hl,bc
... -
Optimal shifting for set pixel?Hi, I'm optimizing my set pixel code. For speed. But without using partitioned memory (i.e. a table on 256 byte boundary) I have optimal memory addr…
What kayamon said + table can be at any place ( ld hl, tab \ ld d, 0 \ ld e, entry \ add hl, de \ ld a, (hl))
Also, this could work:
ld (jump+1), a \ ld a, 1 \ jump: jr 0 \ rla \ rla \ rla \ rla \ rla \ rla \ rla -
Beautiful codeSome people see beauty or something sublime in maths formulas and equations, can anyone suggest examples of beautiful or sublime programming?
... means it was done by a compiler ;)
HL=HL+A[/B]
Standard:
[CODE]ADD A,L
LD L,A ... CODE]ADD A,L
LD L,A
ADC A,H ;A=A0 ... +L+H+carry
SUB L ;A=A ... )=H+carry
LD H,A
[/CODE]
...
