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Ports AccelerationOn ZX48 or 128/+2(grey) is contended and uncontended ports. For example: if you will read 512 bytes sector from IDE device to ZX ram via INI or INIR,…
... ZX ram via INI or INIR, half of all ports will ...
LD B,0
INIR
New read sequence ... /> LD B,A
NOP ; (LD B,A + NOP = 8T)
64x ...
LD B,A
NOP
64x INI
LD ... B,A
NOP
64x INI
Spin Assembler DirectivesLeading on from [URL="http://www.worldofspectrum.org/forums/showpost.php?p=402514&postcount=65"]jp's recent post in Spin 0.7 Public Testing thread[/U…
... : 49+($FFEDA2 shl 8)), (S: 'INIR'; I: 50+($FFEDB2 shl 8 ... /> (S: 'NOOPT'; I: 61), (S: 'NOP'; I: 62+($FF0000 shl 8 ...Spin Assembler DirectivesLeading on from [URL="http://www.worldofspectrum.org/forums/showpost.php?p=402514&postcount=65"]jp's recent post in Spin 0.7 Public Testing thread[/U…
... : 49+($FFEDA2 shl 8)), (S: 'INIR'; I: 50+($FFEDB2 shl 8 ... /> (S: 'NOOPT'; I: 61), (S: 'NOP'; I: 62+($FF0000 shl 8 ...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?
... +1. B=B-1.
INIR Perform an INI and repeat ... accumulator (2's complement).
NOP No operation.
OR s ...Short Z80 QuizQ1) Which program gives different result ? A) XOR A ADD A,A B) XOR A ADC A,A C) SCF ADD A,A D) SCF ADC A,A Q2) What is the equivalent of NEG …
... /> LOOP: LD (HL),B
NOP
INC HL
DJNZ ...InterruptsA small piece intended for the FAQ. Comments, corrections, additions welcome. Notably: * How long does the 48K ULA hold /INT low? * What happens i…
... one primitive operation. For example, NOP has just one M-cycle ...unused assembler commands?Z80 processor has commands like OUTI OUTD OTIR OTDR INI IND INIR INDR.They deal with sending /reading bolcks ofinformation to ports. The problem is, …
... OUTD OTIR OTDR INI IND INIR INDR.They deal with sending ...I/O contention model questionHi everyone, Sorry for my poor english. Together with a friend we are working on ZX Spectrum 48k implemented in FPGA. We have found bug in the Spect…
... IO machine cycle during INI/INIR/IND/INDR execution in ZX ...Currah MicroSource emulationIt appears to be impossible to emualte the MicroSource in software on the ZX Spectrum SE as hardware polling is required. The following patch is not …
... /> nop ; $18fe
nop ; $18ff
nop ; $1900
nop ; $1901
nop ; $1902
nop ... ; $1903
nop ...Help hacking Split PersonalitiesI`ve been hacking away at Split Personalities for the purpose of putting new screens and graphics (items). The current screen is at 41187 and is 160…
... 128
nop ; 54579 0
nop ; 54580 0
nop ; 54581 0 ... 12
nop ; 54588 0
nop ; 54589 0
nop ; 54590 0 ... 192
nop ; 54617 0
nop ; 54618 0
nop ; 54619 0 ...The direct bus or indirect one... that is the questionThe Ethernet project continues...and I'm in a quandry. So I've managed to implement enough socket library for the W5100 that socket, bind, listen, a…
... than 256 bytes) since OTIR/INIR take the same number of ...DJNZ e ProblemI'm trying to write the DJNZ e instruction as part of the development of my emulator and can't get it to work. Here is the in and out states of Phil…
... this right?
0x00 = NOP (PC = 0x0001)
B ...Undocumented DD opcodesHi, I'm emulating the DD-prefixed opcodes at the moment. What happens to an undocumented DD opcode - Phil's test suite doesn't test them. For insta…
... ; does this just execute a NOP? Two NOPs?
Thanks ...25 years with the SpectrumTo paraphrase JFK, ask not what your Spectrum can do for you, but what you can do for your Spectrum. Well I've done quite a bit since I joined the sc…
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 …
... br /> interrupt_delay_loop
nop ;04t => 004t
nop ;04t => 008t ...
nop ;Timing adjustment tweaks
nop
nop
; ... /> push af
nop ;Timing adjustment tweaks
nop
ENDM ;Repeat ...A tidy loader for minigamesThe minigame competition doesn't permit the use of separate loaders like [code]10 LOAD "": RAND USR 32768[/code] The loader must be included in the b…
The minigame competition doesn't permit the use of separate loaders like
[code]10 LOAD "": RAND USR 32768[/code]
The loader must be included in the byte count.
In an attempt to save as many bytes as possible, people have written ...iXpectum 1.2 HD (iPad enabled) is out!iXpectrum now supports iPad on jailbroken devices ;) Thanks to Ryosaebaa for his support... You can download by now at: [url]http://code.google.co…
... contention in IND,INDR,INI,INIR instructions.
- Fixed flags in ...designing a computerHi everyone! I am designing a 4 bit computer and i need some advice, is this a good instruction set? [CODE] BINARY OPCODE DESCRIPTION 00000 nop…
... OPCODE DESCRIPTION
00000 nop
00001 add add register ...Why doesn't my routine work?I have a "level" defined by 504 bytes (28 squares across x 18 squares down) I'm trying to write a routine that will take an X,Y coordinate in pixels…
... ! :)
[code]
compare_xy: nop ;
ld h, 0 ; Clear ...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]…
... />
__DRAW_SETUP1:
xor a ; nop
ld (__PLOTINVERSE), a
__FASTPLOT:
__PLOTINVERSE:
nop ; Replace with CPL if INVERSE ...RAND USR that doesn't work in emulators and clonesEons ago, I "discovered" a strange RANDOMIZE USR. This is it: [b]RANDOMIZE USR 46578[/b] Using it on a genuine ZX Spectrum rubber key or Plus model,…
... USR proposed just begins executing NOP's until the CPU meets ...Back to BASIC[U][B]Archaeology guide to programs compiled used MCODERII.d[/B][/U] After various people have been talking about "Frank'n'stein" I decided to finis…
... compiled program :
[CODE]start NOP
+1 LD HL,0 ...Bride of Frankenstein TAP has been hackedThe Bride of Frankenstein TAP on WoS doesn't have any spooks in it, so you're just wandering around an empty maze. This is because there's a RET at $…
... ; 8A9B 21 D1 96 change: NOP : NOP : NOP
DEC (HL) ; 8A9E 35 ... NOP
JP P, $8ABA ; 8A9F ...Cobra (improved BUGFIX)This is an improved BUGFIX for game [URL="http://www.worldofspectrum.org/infoseekid.cgi?id=0000996"]Cobra[/URL], please replace the "known errors" de…
... /> 9603: or c
9604: nop
9605: jr nz,$9601 ...automatic relocating of non-relocatable codeI was pondering upon the problem of changing absolute addresses used by CALL, JP, etc. when code is moved, without reassembling at the new location; …
... +1,CALLSR,$0000
MAINCD: nop
MODA00: call CALLSR
ret
CALLSR: nop
ret
[/code]Tile based graphics and scrolling thingy...Here's my best attempt so far at a tile based rendering and scrolling routine. It draws in 22 8*8 graphics tiles along the top of the screen (junk i…
... br />
stackptr_temp nop ; 2 bytes @ 32859
nop
next_tile_line ... nop ; 2 bytes for address ... of next tle line
nop
scroll_down push ...Invalid combination of operands and opcodesIt says the error in the title, why is this?? [CODE] ORG 0000 LD HL, 63000 ;LOAD HL WITH STACK LOCATION LD SP, HL ;SET STACK POINTER TO HL LD A, …
... SHOW SPLASH SCREEN
NOP
NOP
NOP
NOP
DJNZ BIOS_DELAY_LOOP ...28-character wide multicolour(ish) on 48k SpectrumLong-time lurker here... I've always been interested in rainbow effects on the 48k Spectrum, mainly from a perspective of "Just what [I]would [/I]ha…
... changes
nop
nop
nop
nop
nop
nop
DJNZ ...
nop
nop
nop
nop
nop
nop
LD ... PUSH HL
nop
nop
nop
nop
nop ; Deal with the ...
