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generating a pre-defined list in an un-defined sequenceI've decided to become a drunkard, to which end I've been drinking a whole bottle of beer in one day (whereas normally I'd make it last 2 or 3 days).…
A galois lfsr is simpler to implement. Here's a version that (might) work:
[code]
start:
ld de,0 ; repeat 65536 times
ld hl,$3141 ; initial lfsr state
lfsr_galois:
... -
Bug in Super Wonder Boy in Monsterland?Hello!:smile: This game seems to have a bug that prevents finalize. The dragon that is in the last level, it is impossible to kill.Remains static.No…
... $23 ;correct victory message scroll screen address
org $ ... br /> ; graphical corruption (falling off screen)
;=============================================================================
corruptionA ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... h,0 ; Calculate character base address
ld l,a
ld de,(printparam+2) ; Screen address
ld b,8
screen, and printparam+4 is a ... -
display file addressing; screen slicingWhile working on this Compendium I'm updating or rewriting a lot of stuff. One thing I eventually came to appreciate was the simple & clever way in w…
... value is used for the screen address.
H is the ... high byte of the screen address integer
L is the ... byte of the screen address integer
The screen is divided into ... -
display file addressing; screen slicingWhile working on this Compendium I'm updating or rewriting a lot of stuff. One thing I eventually came to appreciate was the simple & clever way in w…
... use 2/3 of the screen in height, your table ... read a two-byte screen address out of the table.
screen, consider having the high ... off the top of the screen, and the last 32 ... your sprites - anything off-screen is simply diverted away from ... -
I have done a Spectrum Screen Design Template As PDFI use this for my games, to work out attribute and screen addresses. It is A4, to be printed landscape [url="http://www.peargames.co.uk/downloads/s…
... Google Docs spreadsheet to calculate screen address from pixel or character coords ... get the coords from a screen address.
Pretty much does ... as it's called "Spectrum Screen - Public Version" you may guess ... -
Help with calculating screen addresses[SIZE=3][FONT=Calibri]I?m having a bit of a coding session whilst at work so can?t spend too much time on my current problem. I?m sure someone on thi…
... /> 330 // saddr = screen address
331 // aaddr = attribute address
332 //
screen address
344 // zx_saddr2aaddr( ... return the attribute address corresponding to the given screen address
345 ... -
Joffa Smiff RememberedMemories we keep one by one, Things you said, Things you have done, They bring a smile, Often a tear, Always a wish that you were here. Jonathan "Jo…
... of the sprite, so your screen addresses INC by 1 byte ... reset or subtract from the screen address. Though that only seems to ... -
SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... af ; take scan_loop return address off stack
ld ... , 49152 ; point to alternate screen address
.endif
... ld hl, bitmap ; point to screen address
.endif
ld ... pop ix ; unstack base address
jr nc, ld_look_h ... -
SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
...
push de ; stack screen start address
push hl ; stack ... /> s_sc_rows:
inc d ; next screen address
inc hl ; next bitmap ... ; 8
pop de ; unstack screen address
pop bc ; unstack character ... -
Copy 4Kb in Assembly?Here's an interesting problem: what's the best way to copy a block of 4Kb in assembly? The most obvious solution is to use [B]LDIR[/B]: [CODE] l…
... and DE is the destination address):[code] ld a, ( ... B] referencing a certain bitmap screen address, [B]BC[/B] ... referencing the corresponding attribute screen address, and [B]HL[/B] ... the corresponding pair in buffer address. In this case, ... -
FZX: a new standard format and driver for proportional fonts[B]FZX[/B] is a very compact and efficient (although extremely flexible and powerful) standard format to create new fonts for the ZX-Spectrum. It sup…
... :
inc h ; move screen address by 1 pixel down
inc h ; move screen address by 1 pixel down
FZX: a new standard format and driver for proportional fonts[B]FZX[/B] is a very compact and efficient (although extremely flexible and powerful) standard format to create new fonts for the ZX-Spectrum. It sup…
... :
inc h ; move screen address by 1 pixel down
inc h ; move screen address by 1 pixel down
SCREEN$ bug fixI've been using the SCREEN$() function recently for reading data off the screen rather than taking up space with an array and I got fed up with the s…
... need to recalculate the screen address as I now ... /> pop hl ;HL=runtime address of BlockGen
ld bc ... ;E =lo-byte of screen address
ld a,c ... ;D =hi-byte of screen address
ld (23680), ...bitmap address to attribute addressI've searched, but I don't seem to find the proper keywords. I have a bitmap screen address in DL, character aligned (the address of the top byte of…
... /> I have a bitmap screen address in DL, character aligned ( ... the corresponding attribute address fiddling with that bitmap address?
< ... On entry HL = Display file address
; Preserved HL, BC ... /> ; Exit ;DE = Attr address
DF-ATT ...bitmap address to attribute addressI've searched, but I don't seem to find the proper keywords. I have a bitmap screen address in DL, character aligned (the address of the top byte of…
... to $XX40;
DE = screen address
58 58 58 ... )
ld l,e ;attr address into HL
5 ...Small demo to show my sprite engine for ZX Spectrum 48KThis demo shows 13 sprites moving at 50fps totally flicker free: 12 enemies bouncing in edges and the main character, controllable with OPSA (note S …
... observed) a 40000 cycles flip screen every frame. This is almost ... switch between normal a shadow screen at the begining of the ... - each buffer corresponding to a screen third), and basically make your ... high byte of a given screen address. Then as you erase/draw ...Elliptical ChallengeSubsequent to the recent "Graph Plot" thread, I wrote this general purpose ellipse drawing routine which will plot (although it doesn't actually use …
How to print logo onto screen at chosen coordinates?Hi, I've just got back into zx spectrum games after all these years and after seeing some of the great games on here I would like to start learning p…
... about bytes and bits and screen composition etc :razz:[/QUOTE]
screen address. (or any RAM address)
An integer ... the high byte of the screen address integer
L is ... the low byte of the screen address integer
Here is ...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 de,#4000 ;screen address (D must be #40, ... 3C00 ;BC=ROM font address
ld l,a ... add hl,bc ;HL=address of the source character graphics ... inc ix ;advance the string/screen pointers
inc e ... jr z,TEXTPRINT ;if new screen third -> leave D ...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…
... br /> ld de,$4000 ;screen address (D must be #40, ... graphic ;BC=ROM font address
ld l,a ... *8
;HL=address of the source character graphics ... inc ix ;advance the string/screen pointers
inc e ... z,TEXTPRINT ;if new screen third -> leave D ...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…
... CALL to calculate the attribute screen address. This is the one by ... containing attribute co-ordinates on screen
ld a,(de) ; get ... in the right place on screen[/code]
[Edit ...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…
... once I have the screen address of the spot where ...
note: it expects the screen address in DE
... get the high byte of screen address
rra ; divide ... 4 bits of the attribute address
or 0x58 ...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…
... /> ; ****************
push hl ; save the screen address for later...
; ****************
pop hl ; now get that screen address to be converted to the ... br /> ld l,a ; address of screen position in de
ret ...New test for finding missing +2A/+3 ULA timing detailsHello, having added the +2A/+3 emulation recently, I want to make sure I got the ULA timing 100% right. We know when the contention pattern starts, …
... attribute from the shadow screen combined with the pixels ... from the normal screen.
... reason on +3 the screen flip happening between pixels ... pixels from the same screen as the attribute. ... +3 ULA prepares the screen address on the bus. But ...FZX: a new standard format and driver for proportional fonts[B]FZX[/B] is a very compact and efficient (although extremely flexible and powerful) standard format to create new fonts for the ZX-Spectrum. It sup…
... pattern is generated from the screen address.
The OR/XOR ...Help needed with calculating screen addressesCan anyone help me finally crack Jonathan Cauldwell's screen addressing calculator and, more to the point, is the reason I'm struggling because this …
... back with
HL=RAM-address of this pixel and
screen address and have it give me ...Help needed with calculating screen addressesCan anyone help me finally crack Jonathan Cauldwell's screen addressing calculator and, more to the point, is the reason I'm struggling because this …
... url]
Every screen address, attribute address, character and pixel coordinate manipulation ... view=markup"]asm_zx_saddr2px.asm[/URL] (screen address to pixel x)
[ ... asm[/URL] (screen address to pixel y)
The screen address does not ...
