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finding largest value (z80 assembly)suppose we have to write z80 program which requires to find the biggest value in a block of memory starts from the address 101h until address stored …
... block to search
load bc with the length of the ... -
finding largest value (z80 assembly)suppose we have to write z80 program which requires to find the biggest value in a block of memory starts from the address 101h until address stored …
... block to search
load bc with the length of the ... -
playing sound samples from Boriel's zxbasic-compilerfirst of all, sorry if it sounds confusing if i'm posting this thread here instead instead of at Discussions:SinclarBasic it's because this is more …
... /> ld hl,sample
ld bc,length
exx
16 cpi ; hl++, bc--, p/v flag set if ... bc==0
10 jp po, ... -
Is ESXDOS flexible enough to incorporate e.g. Spectranet commands?I was just discussing the idea with someone about the wish some people have to be able to combine interfaces such as DivIDE (Plus) / DivMMC EnJOY! wi…
... position
cpi ; hl++, bc--
ld a ... ; de = void *buffer
; bc = uint buffer_len
;
; ... byte written)
; bc = remaining space in buffer< ... -
BC BillThis is embarrassing but here goes... I'm playing BC Bill using ZX32. On the control menu I press 2 to select 'Kempston'. What do I need to do then …
... ...
I'm playing BC Bill using ZX32. On the ... -
DEC BC/LD A,B/OR C/JP NZ,loopyesterday i saw nice trick:[code] dec bc ld a, b or c jp nz, loop can be replaced (bc starts >255, short jump) by: dec bc inc b djnz loop [/code] …
yesterday i saw nice trick:[code]
dec bc
ld a, b
or c
jp nz, loop
can be replaced (bc starts >255, short jump) by:
dec bc
inc b
djnz loop
[/code]
..nice -
Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... concepts (jumps, flow control, routines, CPI):
[code]searchmem
[COLOR=DimGray]; ... test for bc==0 here[/COLOR]
jr ...
push hl
pop bc ; retrieve address
ret
CPI emulationI'm currently writing Sinclairean's emulation assembly for the CPI/CPD/CPIR/CPDR instruction group. Does anybody know what exactly the behavior of th…
... 's emulation assembly for the CPI/CPD/CPIR/CPDR instruction group ...BC's Quest for Tires code sheet missingSpeaking of [URL="http://www.worldofspectrum.org/forums/showthread.php?t=35314"]missing code sheets[/URL], it appears the sheet for [URL="http://www.…
... .org/infoseekid.cgi?id=0000477"]BC's Quest for Tires[/URL ...SBC IX,DE/BCAlways wondered why there wasn't a SBC IX, DE/BC command.... so have to use PUSH HL ; save original HL PUSH IX ; IX on stack POP HL ; IX …
... 't a SBC IX, DE/BC command....
so have ... is the value to subtract, BC is the counter. Another note ...Fuse tests - INC BC causes contention delayHi all, In the FUSE test suite it has the following for the output of opCode 0x3 (INC BC): 0 MC 0000 4 MR 0000 03 4 MC 0001 …
... output of opCode 0x3 (INC BC):
0 MC 0000 ... understand is why incrementing the BC pair should introduce two contentions ...Problem with BC corrupting after DJNZJust for fun, I'm messing around trying to get the level maps from Lemmings to display on the screen with machine code. It's been ages since I did an…
... />
LOOP1 LD BC,8 ; SET THE COUNTER FOR ... LINES
LOOP2 PUSH BC ; STORE THE LINE COUNTER ...
LD BC,32 ; SET THE COUNTER FOR ... NEXT LINE
POP BC ; RETRIEVE THE LINE COUNTER ... on screen, after popping BC the DJNZ doesn't ...Machine Code ChallengeHere's a challenge for all you Z80 programmers. Points to be awarded for elegance and brevity. (I haven't got the solution either) HL addresses the …
... C,B ; Set LSB of BC to B.
XOR A ... ; Set MSB of BC to 0.
LD B ... no reset bits.
Skip CPI ; Zero flag reset when a ...Machine Code ChallengeHere's a challenge for all you Z80 programmers. Points to be awarded for elegance and brevity. (I haven't got the solution either) HL addresses the …
... C,B ; Set LSB of BC to B.
800D AF ... XOR A ; Set MSB of BC to 0.
800E 47 ... .
8013 EDA1 16 Skip CPI ; Zero flag reset when a ...ZXSpin 0.61 Available nowHi all! Well, after a lengthy few testing cycles, I'm taking the plunge and uploading the latest version of ZXSpin, to replace the rather aged old 0…
... Spectaculator 5.3 fails in cpi, cpd and the group ( I ... ,(+1)
bit n,
cpi
And I ...Machine code help pls: LDI example[deleted]
... Found code also execute if BC=0? After all this ... quote]
Nope, a CPI instruction only sets/resets the ... comparison - the value of BC doesn't enter into it ... can think of CPI as internally doing a DEC BC instruction, which ... that's the way CPI works...)Machine code help pls: LDI example[deleted]
... , this time regarding CPI ...
CPI compares A with ... (HL), incs HL and decs BC (the ... long:
Search CPI
JR Z, Found< ...
By heart,
CPI set Z if A=(HL ... this
CPI
JR Z,AISHL
Machine code help pls: LDI example[deleted]
... BEEP;320895]By heart,
CPI set Z if A=(HL ... ) and sets P-vlag when BC=0
You can ... do this
CPI
JR Z,AISHL
yup,
LDI/LDD
CPI/CPD
are same ... /V flag to zero when BC==0
JP PO ...Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... concepts (jumps, flow control, routines, CPI):
[code]searchmem
[COLOR=DimGray]; ... test for bc==0 here[/COLOR]
jr ...
push hl
pop bc ; retrieve address
ret
Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... a = 0
ld bc, 0ffffh ; search the entire ... address 0
search: cpi ; a-(HL)
... or c ; flag decoy. BC==0
ld a, ... push hl
pop bc ; retrieve address
...Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... a = 0
ld bc, 0ffffh ; search the entire ... address 0
search: cpi ; a-(HL)
... or c ; flag decoy. BC==0
jr nz, ... push hl
pop bc ; retrieve address
...Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... />
[code]searchmem
ld bc, 0ffffh ; search the entire memory ... for 0. reset flags
cpi ; a-(HL)
jr z ...
push hl
pop bc ; retrieve address
ret
Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
CPI and friends affect the parity ... based on the value of BC. Whilst BC > 0, the parity ... .
[code]
search: cpi ; a-(HL)
jr z ...
[COLOR=DimGray]; ... test for bc==0 here[/COLOR]
jp ...Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... for 0. reset flags
cpi ; a-(HL)
jr z ... found
jp pe, search ; BC!=0
ret ; not found ... br /> push hl
pop bc ; retrieve address
ret[/ ...Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... for 0. reset flags
cpi ; a-(HL)
jr z ... found
jp pe, search ; BC!=0
ret ; not found ... br /> push hl
pop bc ; retrieve address
ret
Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... for 0. reset flags
cpi ; a-(HL)
jr z ... .found
jp pe, .search ; BC!=0
ret ; not found ... br /> push hl
pop bc ; retrieve address
ret< ...Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... for 0. reset flags
cpi ; a-(HL)
jr z ... .found
jp pe, .search ; BC!=0
ret ; not found ... br /> push hl
pop bc ; retrieve address
ret< ...Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... ret po
jr .search ; BC!=0
ret ; not found ... the entire memory
.search cpi ; a-(HL)
jr ... ret po
jr .search ; BC!=0
ret ; not found ...Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... s worth mentioning that CPI doesn't have to ... HL = HL + 1
dec bc ;BC = BC - 1
ld ... !
cpi ;HL = HL + 1, BC = BC -1
;And ... the second routine the CPI isn't being used ...The Goldfinch updates thread([url=http://www.worldofspectrum.org/forums/showthread.php?t=25034]original announcement thread here[/url] - I figured it was worth starting a new to…
...
cpi ; inc hl, dec bc, set PO=true if BC=0
CPI trick[/url] :-)
