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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 …
... /> ld hl, $5b00
loop0 ld a, (bc)
and l
ld (hl), b ... /> Needly use of the opcode 33, but the previous version tested ... decimal switch of 21 and 33 and 23 -
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 …
... defb 62 ; ld a,33
st ld hl,$5b2b ; dec hl / ld e,e
and l
ld (hl ... po,$16ff ; use ROM for LD (HL),B
bit 3,h ... -
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 …
... 62 ; ld a,33
st ld hl,$5b2b ; dec hl / ld e,e< ... br /> and l
ld (hl ... ,$16ff ; use ROM for LD (HL),B
bit 3, ... same cycles (7) as LD A,(BC), so both ... -
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…
... /> EX AF,AF'
MV3 LD HL,33*256+34 ;AF'
PUSH ... /> LD HL,22528
LD (CurrentLineStart),HL
LD HL,AttrBuffer2
LD (CurrentLineAttrs),HL
LD ... -
j symbol-shift p pA phrase I will never forget... and apart from the word code, i don't think I learnt ANY of the other keywords off by heart.... Without looking, whic…
... now long forgotten (except 33 for LD HL, 17 for LD DE, and very ... -
PRINT a numerical value i.e. the scoreHow do you fo about printing a numerical value using the print routine in the ROM? For instance I have a value 0-255 and want to PRINT the result at…
... ,high-1
ld hl,score-1
ld bc,6
... inc hl
inc de
ld a,(de)
cp (hl)
nohigh defb 33 ; hide LDIR in LD HL,nn
sethigh ldir ... -
PRINT a numerical value i.e. the scoreHow do you fo about printing a numerical value using the print routine in the ROM? For instance I have a value 0-255 and want to PRINT the result at…
... ,high-1
ld hl,score-1
ld bc,6
fhigh ...
nohigh defb 33 ; hide LDIR in LD HL,nn
sethigh ldir ... score. [2] Hiding LDIR using LD HL, nnnn to save thsoe costly ... -
Converting UDG to 2x2I've got a udg that I want to display in different sizes. Obviously I just print it for normal size, I can use the udg in bin format to display it ea…
I reinvented the wheel for ZX Basic a bit ago...
[code]' My own dbl size.
' Mi idea es usar una tabla para la expansi?n de los nibbles.
' Para cada byte, se aislan los nibbles, se obtiene la tabla,
' y se vuelca dos ... -
ZX-Preview 2.1 publishedDear friends and ZX-Speccy fans! Today I've released a new version of ZX-Preview. I completed the to-do-list for the program and added the following…
... 2C 2D 30 31 32 33 7C 36 ,-0123|6
33,$7C,$36 ; $C058 ,-0123|6 ... listing
e.g. LD HL,($5800)
OR $DD
ZX7: an "optimal" LZ77 packerAbout 20 years ago, I started a M.Sc. in Computing, planning to work on data compression. Although I quickly changed to another subject for a number …
... CODE]
ld hl, 0
ld de, 0
ld ix, 75 ... br /> inc hl
defb $cb, $33 ; opcode for ... more bits left?
ld a, (hl) ; load another group ...RCS (Reverse Computer Screen)[B]RCS[/B] ("Reverse Computer Screen", or simply SCR written backwards) is a small utility I'm about to release, that reorders bytes from the ZX-Spec…
... (offset=1)
0001-0111 xxxx 7*(2^4)=112 values ... hl
ld hl, $f871
add hl, de
ex de, hl
pop hl ...Spectranet updateHi all It's been a busy summer, and in any case I've wanted a little bit of a break from doing Speccy stuff to avoid it getting old (pun intended). …
... this:
[code]
ld de, address
call GET_IFCONFIG_INET ... , 16384
21 6F 3E LD HL, GET_IFCONFIG_INET ; =0x3E6F
CD FA ... />
DATA 17,0,64,33,111,62,205,250,63 ...Keyboard TrickI know how to use the multi key in BASIC with IN you can get the keys [QUOTE]IN 254+256*(255-2^K)[/QUOTE] K is the keyboard's half row, comes from …
... 49152
LD HL, result
PUSH HL ; Will return buffer position ... later
LD BC, 254 ... , (C)
.loop3: RRCA
LD (HL), 0
JR C, .skip ... are the bytes:
[code]33,31,192,229,1,254 ...Disabling the +3 disk buffer; yes, but how?I would like to disable the +3 disk buffer in order to retrieve those 4K from the machine's RAMdisk. By reading the computer manual and some posts on…
... .....
LD A,7
LD BC,32765
PUSH ... BC
DI
LD ( 23388 ),A
OUT (C ... br /> EI
LD DE,00000
LD HL,00128
CALL 00319 ...
LD A,16
33,128,0,205,63,1 ...Assembler v Machine CodeHi. I've been looking at a lot of the code examples in the Development section and can see that Assembler is the way to go. However, I was wondering …
... (for instance [B]LD HL[/B] is 33 and [B]LD DE[/B] is ...Assembler v Machine CodeHi. I've been looking at a lot of the code examples in the Development section and can see that Assembler is the way to go. However, I was wondering …
... .
[code]
setval LD A,3
DEFB 254 ... A
INC A
LD (setval+1),A
[/code ... C,set
XOR (HL)
set LD (HL),A
INC H ... commands are DEFB 33 (hide 2 values in HL) or JP when ...Assembler v Machine CodeHi. I've been looking at a lot of the code examples in the Development section and can see that Assembler is the way to go. However, I was wondering …
... do stuff like DATA 33, N, ST+1000 (LD HL, ST+1000). N ...Printing textThis is probably quite a basic question, or there might be something obvious I'm missing. I'm looking for an economical way of printing formatted te…
...
ex de,hl
print_text:
ld a,(hl)
cp ... /> add a,33
ld c,a ;set column
push hl
call $0dd9 ;CL_SET
pop hl
jr next_char
print_char ...Games featuring... relevant bugsThere was a recent improvement to the WoS database in order to classify [URL="http://www.worldofspectrum.org/forums/showthread.php?t=34261"]Games fea…
... colour routine
c5c9: ld c, $40 ;bright
c5cb ... /> 9112: ld hl, $c5d4
9115: inc (hl)
9116: ld a, (hl)
9117 ... 9121: jr $9119
9123: ld c, $40
9125: call ... /> [code]
bd87: ld a, $01
bd89: ld ($d8f7), a ;stop ...Games featuring... relevant bugsThere was a recent improvement to the WoS database in order to classify [URL="http://www.worldofspectrum.org/forums/showthread.php?t=34261"]Games fea…
... /> 7310: ld a, (hl) ;
7311: xor $40 ;
7313: ld (hl), a ;toggle ... off
ld hl,$fc0e ;33 14 252
res 6,(hl) ;203 182 ... off
ld hl,$fc14 ;33 20 252
res 6,(hl) ;203 182 ...Scrolling by 2 pixelsWhat is the fastest way of scrolling a Spectrum screen line by 2 pixels left or right? When thinking about it I've come to this simple solution: [C…
... .
The 1st routine is 33 bytes and takes approx. ?????T ... /> SCROLL2RR:
ld c,8
ld hl,16384
ld de,256-32 ...
ld hl,256-32
add hl,sp
ld sp,hl
dec ...Movin And A Groovin Horizontal Flip improvementOn the left is the flip horizontal portion from Andy Pennell'S excellent Movin' & a Groovin' machine code screen routines from Your Spectrum #19 (Oct…
... ld hl,#4000 210040
ld de,#401f 111F40
rpt ld a,(hl ... /> ld a,(hl) 7E
exx D9
ld (hl),a ... start ld hl,tableaddr 2100XX
ld b,l 45
ld ... nc,rpt 30FB
ld (hl),c 71
inc ... 13 93 53 D3 33 B3 73 F3
RCS (Reverse Computer Screen)[B]RCS[/B] ("Reverse Computer Screen", or simply SCR written backwards) is a small utility I'm about to release, that reorders bytes from the ZX-Spec…
... I've got it to 33 Bytes and working with full ...
210040 ld hl,$4000
7C loop ld a,h
09 add hl,bc
7E ld a,(hl)
12 ld (de),a ... ld bc $0300
EDB0 ldir
C9 ret
33 ...
