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Supertest 128 - Loader QuestionI wonder if someone could explain (in simple terms please) :) , the purpose of the switch code. I see what is doing (going to 48k mode via spectrum)…
... /> ;
diewith:
push af
ld iy,DDOFF ...
ei
pop af
cp 10< ... />
dodos: push af
push bc
ld bc ... pop bc
pop af
call pciy
push af
push ... /> ei
pop bc
pop af
ret< ... -
Z80 Processor Interupt helpHi everyone, Currently designing a Z80 computer and i need a little help with these interupts. If i have an I/O device that sends a pulse to the int…
... 's supposed to push current address and pop it after the interrupt ... -
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…
... This way I can pop them back from thread descriptor ... ; 6 M-cycles
push af ; 3 M-cycles
push bc ; 3 M-cycles
push hl ; push sp
; hl ... /> inc hl
push hl ; push pc (note: wrong order)< ... -
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…
...
59 pop iy
60 pop ix
61 pop hl
62 pop de
67 pop de
68 pop bc
69 pop af
82 push af
83 push bc
84 push de
Gigascreen - programming guideDoes anyone know of a programming guide for the 128K gigascreen screen mode, specifically a persistence colours table, some code (pref. C level or BA…
... back here
PUSH AF ;Store numbers on ... ll get messed...
PUSH HL ;...around with.
PUSH HL ;Copy HL (attribute address)...
POP DE ... br /> POP HL ;Recover numbers...
POP DE ;...
POP AF ...Sprites masterclassHi All, You guys are probably tired of explaining sprites but I'd like to clarify a few things if possible. I've sorted the vertical aspect of scro…
... = key 1
push af ;remember value on stack ... push af
call nc,mpu ;being pressed?
pop ... af
rra
push af
... call nc,mpl
pop af< ... br /> rra
push af
...Sprites masterclassHi All, You guys are probably tired of explaining sprites but I'd like to clarify a few things if possible. I've sorted the vertical aspect of scro…
... hl
push hl
call put_blanksprite
pop hl
... a
put_blanksprite1 push bc
exx
pop bc
exx ... l,a
push hl
exx
pop hl
ret ... /> add hl,de
push hl
pop ix
ld a ...Calculating the address of a pixel?Hi Folks, Is there an easy/quick way of calculating the memory address of a pixel? So for example, if I wanted to "plot" pixel at screen coordinate…
... something like:
[code]
pop hl - each tile starting address ... block copy operations or even PUSH to the display.[/QUOTE]
I can use PUSH as easy as i can ...DivIDE questionHi all, A while ago I was looking at programming firmware for the DivIDE and was told that, when writing an NMI function, address 0066h (the jump lo…
... the main ROM has a PUSH AF instruction at this address ... , so you'll need to pop it off before returning.
Zombie Zombie Loading SchemeA quick check of the [URL="http://www.worldofspectrum.org/infoseekid.cgi?id=0005866"]Zombie Zombie[/URL] loader identifies it's the RAPID LOADING SYS…
... ; 5d1c c9 $0ats
push de ; 5d1d d5 $0bts
l_5d91: pop af ; 5d91 f1 $0ats< ... ; 5d9e d7 $0bts
pop bc ; 5d9f c1 $0ats
pop bc ; 5db0 c1 $0ats
pop bc ; 5dc7 c1 $0ats
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…
... />
[code]
;; ------------------------------------------------------------
_kbd_init: push hl
ld hl,_kbd_prev ... (hl),0 ; clear _kbd_bend
pop hl
ret
[/code ...Push/Pop data copyingWe all know that stack pointer cheese and push/pop is faster to move data than LDIR - which in turn is slower than unrolled LDI's anyway. I rewrote …
... ]
Well in POP/PUSH, you set the stack to ... the data POP a value off the ... pointer to the screen and PUSH it back, rinse and ... followed by a series of PUSH instructions (which has the ...
PUSH HL
PUSH DE
PUSH BC
PUSH AF
Push/Pop data copyingWe all know that stack pointer cheese and push/pop is faster to move data than LDIR - which in turn is slower than unrolled LDI's anyway. I rewrote …
... />
Updating the SP for POP/PUSH can be done like this ... /> push bc ; 11ts
push bc ; 11ts
push bc ; 11ts
push bc ... ; 11ts
push bc ...Push/Pop data copyingWe all know that stack pointer cheese and push/pop is faster to move data than LDIR - which in turn is slower than unrolled LDI's anyway. I rewrote …
pop reads two bytes from SP into specified register pair and increases SP by two. push decreases SP by two and stores two bytes from specified register pair to SP. These operations are not copy anything.Push/Pop data copyingWe all know that stack pointer cheese and push/pop is faster to move data than LDIR - which in turn is slower than unrolled LDI's anyway. I rewrote …
Push/Pop data copyingWe all know that stack pointer cheese and push/pop is faster to move data than LDIR - which in turn is slower than unrolled LDI's anyway. I rewrote …
... . So the only way using POP/PUSH is to use all the ... (without reading about it), that push, pushed the value off the ... the above work would be PUSH (OLDSP), if it existed. You ...50Hurts - Full-screen 50Hz 1-pixel scrolling on a 128K Speccy50Hurts - Full-screen 50Hz 1-pixel horizontal scrolling on a 128K Speccy. Graphics are an obvious nod to Joffa, whose games and banter were a big ins…
... the breakdown of PUSH BC is:
PUSH dd pc:5 ... on average 16T per PUSH instead of the usual 11T ... 24T to do a contended PUSH.
Now ... front of every ordinary PUSH to extend them all ... . That means I only POP each line of each pair ...SE Basic Type-ins^Pete suggested creating a sticky thread for SE Basic discussion. I thought a Type-ins thread might also be useful. Up to the mods if they want to ma…
... /> push hl
push bc
call copy_line
pop bc
pop hl ...SE Basic Type-ins^Pete suggested creating a sticky thread for SE Basic discussion. I thought a Type-ins thread might also be useful. Up to the mods if they want to ma…
... /> push af ;
call doit1 ;
pop af ;
pop de ;
pop bc ... ;
pop hl ;
ret ;
doit1:
push af ... , a ;
pop bc ;+ restore count
push hl ;+ save mask ...SE Basic Type-ins^Pete suggested creating a sticky thread for SE Basic discussion. I thought a Type-ins thread might also be useful. Up to the mods if they want to ma…
... />
zap_loop:
push hl
push de
push bc
ld ... br /> ldir
pop bc
pop de
pop hl
inc ... /> ld c,l
pop hl
push bc
ret
pos_2a:
push bc
push hl
set 5 ...50Hurts - Full-screen 50Hz 1-pixel scrolling on a 128K Speccy50Hurts - Full-screen 50Hz 1-pixel horizontal scrolling on a 128K Speccy. Graphics are an obvious nod to Joffa, whose games and banter were a big ins…
... the other thread on using PUSH to do scrolling. It's ... people were talking about using POP/PUSH to copy data, and how ... is replacing the sequences of PUSH statements in the main drawing ...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…
... by this
push af ; store regs
push hl ; -"-
...
pop af ; -"-
ret
exit_critical_section:
push af ; ... store regs
push hl ; -"-
ld ...50Hurts - Full-screen 50Hz 1-pixel scrolling on a 128K Speccy50Hurts - Full-screen 50Hz 1-pixel horizontal scrolling on a 128K Speccy. Graphics are an obvious nod to Joffa, whose games and banter were a big ins…
... '
ld sp,hl
pop hl
; HL now holds ... sp,iy
pop bc
pop de
pop af
exx ... /> push_8B00:
DUP 14
push af
EDUP
jp ...50Hurts - Full-screen 50Hz 1-pixel scrolling on a 128K Speccy50Hurts - Full-screen 50Hz 1-pixel horizontal scrolling on a 128K Speccy. Graphics are an obvious nod to Joffa, whose games and banter were a big ins…
... the write (PUSH) instructions but doesn't affect the read (POP) instructions ...
