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RFC: 64 column font codeIn BASIC, type CLEAR 49999 then import the code at 50000. Then type RANDOMIZE USR 50000. This will create a new channel and attach stream #4 to it. A…
... of HL
ex af,af' ; save the carry flag
add ... />
even_col:
ex af,af' ; restore char position carry flag
jr c ... />
odd_col:
ex af,af' ; restore char position carry flag
jr nc ... -
A fast DRAW routineI was investigating how to speed up the line drawing for the [URL="http://www.worldofspectrum.org/forums/showthread.php?t=20225"]BASIC compiler[/URL]…
...
ret nc
ex af, af' ; Sets carry on F'
scf ; which ...
ret nc
ex af, af' ; Sets carry on F'
scf ; ...
ret nz
ex af, af' ; Sets carry on F'
scf ; ... -
Any ideas on speeding up this assembler segment?It copies a pixel column of a rectangle which may be anywhere in the display file to a pixel column in d$. The source column may start at any bit pos…
... powerlp:rla ; 4 rotate Carry to correct position
... d$()
ex de,hl ; 4
ex af,af' ; 4
inc a ; 4 A'=pt
ex af,af' ... -
JSW2 - Game Loader DifferencesThere are three official releases of JSW2. I'm not counting the 'JSW2-128' version here as far as I'm aware this was not in any way 'official' as it …
There are three official releases of JSW2. I'm not counting the 'JSW2-128' version here as far as I'm aware this was not in any way 'official' as it incorporates a built in cheat mode. Feedback on this point is appreciated. To quote the readme:
LZ4 decoderI encountered the [URL="http://code.google.com/p/lz4/"]LZ4 compressor[/URL] a few weeks ago. Reading the [URL="http://fastcompression.blogspot.co.uk…
... many bytes
ex af,af' ; switch token back into ... ;;
;; The routine leaves carry clear
.getlength:
ld ... 4T)
and a ; clear carry (4T)
.getlength_nocarry:
...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 +…
... 10
draw_char_frame_loop
push af
inc c
< ...
rl b ;catch carry bit
add a,a ... /> add hl,bc
ex de,hl ;de = address of ... 8 times
ex de,hl
ld a ... br /> ld sp,hl
ex de,hl
...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…
... dual function of [b]ex af,af’[/b]. When no shifting ... br />
[code]
ex af,af' ;store position (0-7) within ... xor a ;clear A and Carry
ex af,af' ;restore pixel position ( ... our shift counter
ex af,af' ;restore A with sprite ...Console frameworkStill working on Specotron, but at the point where working out the diagonal lines collision is not good at beer o'clock. In the meantime I've knoc…
... /> ex af, af'
dec a
jr z, .done
ex af, af'
carry is set if lower bit ... .getkeyval
or a ; clear carry flag
rra ; rotate right ... including carry
jr c, .done< ...Timex 80 column display driverI subsequently wrote an 80 column font driver for 512x192 mode.
... br />
.loop1 ; carry reset here
... ld c,a
ex af,af
or c
.loop2 ; carry reset here
... to right
; carry flag reset
Rainbow Generator for 48K Spectrum using PUSHThis is what I came up with from [B]gasman[/B]'s suggestions. It's stable in ZXSpin and ZX32 simulating a 48K Speccy. Anyone like to try it on the …
...
and a ; clear the carry flag before
; calculation
pop hl
ex af,af' ; exchange registers for alternates
ex af,af'
push hl ; write 8 ...More colours II (Was: Most popular new features?)The suggested 4xCLUT multi-colour solution never took off.
... ; indicate data
scf ; set carry flag - indicate loading
ld ... (c), a ; select register
ex af, af' ; save current register select
ex af, af' ; restore current register
inc ...Z80 'EXX' ConfusionI was working on a little Z80 routine last evening, and, having run out of registers, resorted to sticking one of the values into a memory location a…
There's an extra EX AF,AF' instruction for doing that specifically. ... , IY and the Flags to carry data over from one set ... other. Or you can use AF' to save the flag state ... /POP). Or you can swap AF, BC, DE & HL and ...yeah - unix for zx spectrumI started a new hobby project. An operating system for ZX Spectrum. A unix clone. Talked to my friend about it and he asked me what if after I'm done…
... br /> ;; hl,bc,de,af,af'
;; ------------------------------------------------------------
... e
keydown: ex af,af' ; alternate accu.< ... reset de
endofscan: ex af,af'
ret
...
scf ; carry flag on
...RFC: 64 column font codeIn BASIC, type CLEAR 49999 then import the code at 50000. Then type RANDOMIZE USR 50000. This will create a new channel and attach stream #4 to it. A…
... , a ; clear H
ex af, af' ; save the carry flag
ld d ... />
even_col:
ex af, af' ; restore char position carry flag
jr c ... />
odd_col:
ex af, af' ; restore char position carry flag
jr nc ...GUI/OS for the Spectrum?Hi, Is anybody working on a WIMP/GUI system for the Spec? Is there anything current out there? [url]http://snakeoillabs.com/wordpress/2005/10/30/8…
... , 0 ; clear H
ex af, af' ; save the carry flag
add hl ... />
even_col:
ex af, af' ; restore char position carry flag
jr c ... />
odd_col:
ex af, af' ; restore char position carry flag
jr nc ...Saving and Loading from tape in MC?I'm actually having problems with saving and loading from the ROM routines for the interpreter... I'm currently using the following codes for saving…
... the zero flag without disturbing carry.
EX AF,AF' ; preserve entry flags.
carry.
EX AF,AF' ; preserve entry flags.
Fastest way to mirror a byte?I.E. turning 01100000 into 00000110, in assembly. I'm trying but I suck at stuff with rotation and the carry bit. Any pointers?
... br /> EX AF,AF' Exchange the contents of AF and AF'.
EX DE,HL ... RLA Rotate left accumulator through carry.
RLC (HL) Rotate ... RRA Rotate right accumulator through carry.
RRC m Rotate ...Creating a new game - AssemblySo... finally I?m studying Assembly Z80... after 36 years. :) Well... it?s sooooooooooooo hard to make a game using Assembly? I bought a book (Spectr…
... think I might have used EX AF,AF' in the past so I ... don't need to. Just carry on using whichever ones you ... separately from A (or strictly, AF), with the commands EXX and EX AF,AF'.question re. STR$ bugCould someone point me to whereabouts in the ROM this goes wrong? [code]PRINT PAPER 5;1;STR$ 234[/code] (Only the "1" prints in cyan.) It's not the m…
This routine (48 bytes) provides a BASIC replacement for STR$ which fixes those two bugs; use "FN s$(numeric_expression)" instead of "STR$ numeric_expression". I copied the ROM's method used in CIRCLE & DRAW for checking -1Is there an SNA halt bug?Hello all, I noticed that some SNAs don't work on my emulator but they do work in almost everyone else's, SPUD fails with them too which is a tad sp…
... br /> exx
pop af
ex af, af'
pop hl
... /> ld r,a
pop af
ld sp, (22B0h) ; ... (22B0h), sp
push af
ld a,r
carry flag before.
