Z80 ret nz. There's no need to set the screen attributes.


  • Z80 ret nz Likes Received 370 Posts 718 Bookmarks 2 Map Entry yes. Here is a RET NZ RNZ: POP BC POP B: JP NZ,addr JNZ addr: JP addr JMP addr: CALL NZ addr CNZ addr: PUSH BC PUSH B: ADD n ADI n: RST 0 RST 0: RET Z RZ: RET RET: JP Z,addr JZ addr # * CALL Z addr CZ addr: CALL addr CALL addr: ADC n ACI n: RST 8 RST 1: D: RET NC RNC: POP DE POP D: JP NC,addr JNC addr: OUT A,(p) OUT port: CALL NC addr CNC addr: bit 6, ZF, Zero flag. For the difference between two signed numbers, I think you'd need to Generally good algorithms on z80 use registers in a appropriate form. Back to the index The Z80 CPU contains 208 bits of R/W memory that are available to the programmer. dw dummyret . db "GDB" It's a lot of overhead if your project doesn't need those rectangle routines or the getkey routines, but, you can modify those to use the built-in routines (it's just smoother this way). Společně s Ralphem Ungermanem (1942–2015) uvedli v červenci 1976 procesor Z80 na trh. Refer to the Z80 user manual for a detailed explanation of the instruction set. Though from as far as I've been able to see, ">" isn't as easy. asm at master · jblang/bbcbasic-z80. Key: . The only change is in representation and how we program the handling of the data. Find and fix vulnerabilities MINIMON für Z80 aus C'T 12-1983 abgetippt. Translation by Felipe Monge Corbalán. that's more a higher-level programming thingy) Z80 multivibrator Point: Use Loop Output 00H and FFH at 1 second interval. Syntax: ret (unconditional) or ret condition (conditional) The word on the top of the stack is retrieved and it is used as the address of the next instruction from which the execution is to be continued. Contribute to bchiha/Tiny-Basic-Z80 development by creating an account on GitHub. A Z80 Assembler. Aug 20th 2021 #1; Durch Zufall bin ich in dem C'T Magazin vom Dezember 1983 auf den MINIMON von I am having a bit of trouble with writing some Z80 code and while I have written some code before, it's been a while and I'm still quite uncomfortable with Z80 as compared to 6502. Reload to module Z80::Program::Mnemonics Z80 Mnemonics ¶ ↑. Any idea of what I'm doing wrong? Top. The routine should be called with the X and Y coordinates in a register. Bit Manipulation Instructions (Z80 Only) 8080 Mnemonic Z80 Mnemonic Machine Code Operation — BIT: 0,A: CB47: Z flag <- NOT Bit 0 — BIT: 0,B: CB40: Z flag <- NOT Bit 0 ret HookAddr: add a,e cp 3 ret nz bit appInpPrmptDone,(iy+apiFlg2) res appInpPrmptDone,(iy+apiFlg2) ld b,0 jr z,FinishCont bcall(_ReloadAppEntryVecs) ld hl,appvecs bcall(_AppInit) or 1 ld a,cxExtApps ld (cxCurApp),a ret appvecs: . 00/5 (15 votes) 3 Oct 2020 » Forum > Calculator Programming > z80 & ez80 Assembly. Instant dev environments GitHub Copilot. z80 » Beginner. Anakclusmos; Expert (Posts: 681) TI83+ ASM Transfer Protocol; 28 Nov 2010 09:28:52 pm; Last edited by Anakclusmos on 01 Dec 2010 01:10:52 pm; edited 1 time in total ; From what I'e heard, this is my best attempt at writing a routine to recieve a byte » Forum > Calculator Programming > z80 & ez80 Assembly. 1 endpoints (e. They produce machine code which is added to the Program class instance variable: Program. DJNZ MenuSkipOptions RET MenuSkipMenus: LD A, (HL) INC HL OR A JR NZ, MenuSkipMenus DJNZ MenuSkipMenus RET MenuTitleAddress: . Write better code with AI Security. Main Menu Home; Search; Donations/Subs; CPCWiki forum General Category Programming (Moderator: ComSoft6128) Shrinkler Z80 Z80 CPU User Manual DO NOT USE THIS PRODUCT IN LIFE SUPPORT SYSTEMS. PCh <- (SP+1); SP <- (SP+2) RET NZ C0 If NZ, RET RET Z C8 If Z, RET RET NC D0 If NC, RET RET C D8 If C, RET RET PO E0 If PO, RET RET PE E8 If PE, RET RET P F0 If P, RET RET M F8 If M, RET RETI ED4D Return from Interrupt RETN ED45 IFF1 <- IFF2;RETI RST 0 C7 CALL 0 RST 8 CF CALL 8 RST 10H D7 CALL 10H RST 18H DF z80 cpc timings cheat sheet - timings page 2 1 nop . Here we add two 32-bit integers: LD HL, (word1) ; Get least-significant word of word1 LD DE, (word2) ; Get least-significant word of word2 ADD HL, DE ; Add them LD (result), HL ; Store least-significant result LD HL, (dword1 + 2) ; Get most-significant word of word1 LD DE, Z80 5seconds Timer for 10 MHz Point: Use 3 Loops ORG 0000H LD SP,0FFFFH MAIN: CALL TIMER5 TIMER5:LD E,35H J60: LD B,0FFH J61: LD D,0FFH J62: DEC D JP NZ,J62 DEC B JP NZ,J61 DEC E JP NZ,J60 RET END note: If your system has CTC, it's better to use CTC timer interrupt. The Z80 Processor Instructions At the heart of the Spectrum (and many other computers, such as the Amstrad CPC, MSX, CP/M machines and the Gameboy) is the Zilog Z80A CPU , which runs at approximately 3. It is also a good practise to keep a convention and plan how you are going to use the registers. You can indeed make the ret conditional on other flags, like ret c (return if carry flag is set), ret nz and ret nc (the inverses of ret z and ret c), etc. I decided to use this IC because it is simple to program and therefor simple to test if the communication is actually working Z80 CPU for OpenFPGAs, with Icestudio. Remember that the f register contains the flags as bits. Projects Contests Teachers Z80-mbc2 Z80 Code Flash User LED. The flags are preserved. The z80 has six flags on it total, which are represented in the f register as being either set (1) or reset (0). For an overview of T-states for each instruction, check the “Timing Z80+M1” column in the instruction set overview. You can: Perform relative and absolute jumps. CodeProject is changing. Write the shortest code to wipe the screen by increasing the ink colour of each character until it reaches white. DECODING Z80 OPCODES - of use to disassembler and emulator writers - org 32768 di ld b,0 l1: xor a ld r,a dec hl ld a,h or l jr nz,l1 djnz l1 ei ret It will take about three minutes to run. The only difference between RETI and RETN is that peripheral devices which allow daisy-chaining of interrupts (eg the Z80 PIO) recognise the ED4D sequence as 'end of interrupt' and then know that they can allow a further interrupt to be passed to the ZX Spectrum Assembly, Pong. However, the thing I've just started learning assembly, but I think "sub c \ ret nc \ neg \ ret" is optimal for unsigned numbers. 139 ZS() Instruction Set Summary 433 because of its special usage in the DJNZ instruction. Besides checking the Accumulator value, the code checks if there are no Geräte Z80 Geräte 68000 Geräte 8088 NKC Emulator JR NZ,label: 2 Byte 7 Takte: Programmablauf. By coopzone in Circuits Software. Net (Version 4. let's optimize! mnemonic clock size op-code adc a,(hl) 7 1 8e adc a,(ix+n) 19 3 dd 8e xx adc a,(iy+n) 19 3 fd 8e xx adc a,r 4 1 88+rb adc a,n 7 2 ce xx adc hl,bc 15 2 ed 4a adc hl,de 15 2 ed 5a adc hl,hl 15 2 ed 6a adc hl,sp 15 2 ed 7a add a,(hl) 7 1 86 add a,(ix+n) 19 3 dd 86 xx add a,(iy+n) 19 3 fd 86 xx add a,r 4 1 All they did was add hl,hl / djnz $-1 / ret Z80 Djnz Instruction Read/Download Implementing Additional Instructions and Addressing Modes. ret z ret nz ret c ret nc: ret if zero flag set ret if zero flag reset ret if carry flag set ret if carry flag reset jp addr1: jp z,addr1 jp nz,addr1 jp c,addr1 jp nc,add1: jump if zero flag set jump if zero flag reset jump if carry flag set jump if carry flag reset call addr1 Recently I issued the fifth Z80 challenge for the Sinclair Spectrum: This time the challenge is to write a solid flood fill routine to fill a region of unset pixels, bounded in 4 directions (up, down, left, right) by set pixels or the screen edge. Z80, Z180, Z280, Z380, Programming, Hardware, Software, Utilities, FAQ, Support, CPU, assembler In Solution Explorer, right-click the Code. B. All Z80 instructions are created as singleton methods. Hai CrazyBos, Yer code's correct, both should work to compare an unsigned 16-bit reg. I decided to use this IC because it is simple to program and therefor simple to test if the communication is actually working The z80 has six flags on it total, which are represented in the f register as being either set (1) or reset (0). ORG 0000H LD SP,0FFFFH PPI1 EQU 37H PORTB1 EQU 35H LD A,90H OUT (PPI1),A LOOP: LD A,0 OUT (PORTB1),A CALL TIMER1 LD A,0FFH OUT (PORTB1),A CALL TIMER1 JP LOOP TIMER1: LD E,0AH J50: LD B,0FFH J51: LD D,0FFH J52: DEC D JP NZ,J52 DEC B JP NZ,J51 DEC E JP Integer Math Addition/Subtraction. ; It is required to be followed by a routine called CHROP that outputs a ; single ASCII character. The registers include two sets of six general-purpose registers that may be used individually as 8-bit registers or in pairs as 16-bit registers. There's no need to save the screen area being overwritten or set the 2) It means that the return instruction will only be executed if the zero flag is set. The Accumulator should contain $24 if the code works as expected. Projects . There are a limited number of ways for your programs to communicate with a user. Reload to refresh your session. Kindergartensitzenbleiber . (see also ret) CALL cc,LABEL (where Dec 9, 2020 The z80 has six flags on it total, which are represented in the f register as being either set (1) or reset (0). Z80 Processor Instructions At the heart of the Spectrum (and many other computers, such as the Amstrad CPC, MSX, CP/M machines and the Gameboy) is the Zilog Z80A CPU , which runs at approximately 3. 2. BCD works by using four bits to store each decimal (base 10) digit of a number. z80asm file, and invoke the Run Z80 program command: Note: You can use the Ctrl+M, Ctrl+R double shortcut keys to execute the Run Z80 program. questionsabout the Zilog Z80 Family. I have added $5000 to all Z80; PC-8801; Last updated at 2018 25 call $6f6b ; CRTSET ret vblank: in a, ($40) and $20 jr nz, vblank . Dierch-Jentz; Aug 20th 2021; Thread is marked as Resolved. Documentation for this CPU is often lacking; the most common opcode maps are written down as a standard Z80 map with addenda for the Nintendo modifications. Also slightly touched in this document is the CTC The z80DotNet Macro Assembler is a simple cross-assembler targeting the Zilog Z80 and compatible CPU. Hex Operand/Prefix Operand Answer: Dave Baldwin: - RETI (Return from interrupt) pops the return address from the stack, like RET. Running the 7. Find this and other hardware projects on Hackster. È stato prodotto nel 1976 e ha avuto un grandissimo successo, tanto che è rimasto a listino presso diversi fornitori di materiale elettronico per 48 anni. I was optimising some algorithms and code in Grammer and I came across a pretty big speed optimisation for 1 The Z80 SIO The Z80 SIO is the most powerful I/O device of the Z80 product family. org 32768 di ld b,0 l1: xor a ld r,a dec hl ld a,h or l jr nz,l1 djnz l1 ei ret It will take about three minutes to run. If you press Y=, the equation editor, I wanna run prgmU, but this doesn't seems Z80; PC-8801; Last updated at 2018 25 call $6f6b ; CRTSET ret vblank: in a, ($40) and $20 jr nz, vblank . Otherwise: If the next opcode makes use of HL, H, L, but not (HL), any occurrence of these will Zilog Z80 Assembler. We could have used the CP instruction to evaluate the value System Software for Z80/Z180/Z280 Computers. As I am refreshing my Z80 assembly skills I realized that I don’t have a good understanding of some of the less popular instructions. Skip to content . and a clears the C flag, if sub WATER_TITLE left it set. Example: org 0x8000 pointertable: defw sub1, sub2 sub1: sub b ret nz sub2: ld h,0 ret ds or defs. 1984 neigte sich die Blütezeit der 8 Bit Rechner schon dem Ende zu. Read more. This command compiles the Z80 assembly code to binary machine code, starts (or restarts) the Spectrum virtual machine, injects the binary code, and runs it: EDIT: I found a bug and I managed to optimize out an average of roughly 600 cycles (I got that number from 500 simulations of randomized inputs and multiplying the eZ80 timings by 6. From Learn @ Cemetech. arithmetic & logic cpd cpi bits, flags & special arithmetic bit b,(hl) daa neg incr & decr load ld r,r ld r,n jp (hl) jp (ix) b-1=0 : 3, b-1<>0 : 4 ret push/pop/load with sp/call/ret ld sp,hl ld sp,ix ex (sp),hl ex (sp),ix in/out, special nop in r,(c) outi ind ldir, lddr bc-1=0 : 5 Der "ideale Z80 Heimcomputer" Nachdem ihr im Blog schon etliche Aufsätze über hypothetische Raketen gelesen habt, möchte ich nun mal einen Artikel über einen hypothetischen Computer schreiben. So you've learned a little z80. None of the The RETI instruction also facilitates the nesting of interrupts, allowing higher priority devices to temporarily suspend service of lower priority service routines. RetroComputerInstructionManual Zilog Z80 OpCodes. Sign in Product GitHub Copilot. z80asm file, and invoke the Run Z80 BBC BASIC for the Z80 CPU. As you can see, we only need to add to convert numbers from one base to another, as shown in the example below: 5FA0h 0101 1111 1010 0000 32 + 128 + 256 + 512 + 1024 + 2048 + 4096 + 16384 = 24480 You signed in with another tab or window. Contribute to Obijuan/Z80-FPGA development by creating an account on GitHub. As a note, I found Karatsuba multiplication to be less efficient up to 24-bits and I have yet to write a 32-bit routine. org #8000 Extend to the code with a few lines:; Code file start: . After reading this, hopefully the reader will not feel limited to integer math and not limited to even the representations here. If the next byte is a DD, ED or FD prefix, the current DD prefix is ignored (it's equivalent to a NONI) and processing continues with the next byte. That is, '[' enters assembler mode and ']' exits assembler mode. Along with the technical Manual, Product Specification and some other application Lo Z80 è uno dei primi microprocessori costruiti al mondo (per opera dell'italiano Federico Faggin). If not, it keeps doing its thing, and if it IS equal then it will jump to an ending routing. Condition cc is programmed as one of eight status that correspond to condition bits in the Flag Register (Register F). Scoring is multi-objective: a Z80 LED BLINK(8255-PPI). Find and fix Z80 5seconds Timer for 10 MHz Point: Use 3 Loops ORG 0000H LD SP,0FFFFH MAIN: CALL TIMER5 TIMER5:LD E,35H J60: LD B,0FFH J61: LD D,0FFH J62: DEC D JP NZ,J62 DEC B JP NZ,J61 DEC E JP NZ,J60 RET END note: If your system has CTC, it's better to use CTC timer interrupt. ↑. Hackster is hosting Hackster Holidays, Ep. If you need access to this endpoint, you may need a different access level. DD-PREFIXED OPCODES. For example, instead of getting the instructions: DI; LD SP, 0xC0FF; IM 1; I get: DI; RST 38; RET NZ; IM 1. However, this instruction does The Z80 feeling. 65,938 articles. ×. X*1x0 - BIT b,m 12 die durch b - den Interruptbetrieb benutzt werden KS 0 KS 1 2x Eingang Kanalauswahl 0 bis 3 ld bc,XXXX dec bc inc b inc c ld a,b ld b,c ld c,a loop: ; <do stuff> djnz loop dec c jr nz,loop ret I can't remember if the GB Z80 has the cpi and cpd instructions, but if it does, you can use those to increment/decrement HL and use BC as a loop counter: ld bc,XXXX loop: ; do stuff cpi jp pe,loop ret In Part 4 of this series I implemented a proper clock signal using a crystal and logic, in readiness for adding the TMS9918 video chip into the circuit. Code path analysis can usually tell the difference between code and 1 Z80命令説明書 [はじめに] Z80はザイログ社が開発した8ビットCPUで、8080（インテル社）の命令の全てを含み、さらにその上全く新しい多くの命令を実行 High-fidelity emulation of undocumented Z80 instructions. I have the code for that here, which is an adapted You currently have access to a subset of Twitter API v2 endpoints and limited v1. . If one imagines the codes as being Z80 machine code instructions, then the right hand columns give the corresponding assembly language mnemonics. Product GitHub Copilot. Per molti anni è stato usato sia sugli home-computer, sia per far girare il sistema operativo più diffuso di allora, il CP/M. the x-coordinate is stored in D and the y-coordinate is stored in E 01110 10001 10001 The z80 CPU has an instruction called DJNZ which can be used in a similar manner as a for loop. DW 0 Z-80 Instruction Set. You switched accounts on another tab or window. The scanline technique is a fast, stack-efficient flood fill which can be Branching and looping is fundamental to computing, and the Z80 has a comprehensive set of instructions to support this. Z80 5seconds Timer for 10 MHz Point: Use 3 Loops ORG 0000H LD SP,0FFFFH MAIN: CALL TIMER5 TIMER5:LD E,35H J60: LD B,0FFH J61: LD D,0FFH J62: DEC D JP NZ,J62 DEC B RET. Weitere Informationen finden sie hier. I connected the I2C bus to a breadboard with an PCF 8574 I2C I/O expander. Instant dev environments Issues. Sign in Product Actions. ; The original ORG was $0100. This works very well. Z80 uses this internally for BCD correction. ret z returns with a cleared C (caused by sub WATER_TITLE), because the result of the subtraction is zero. If the next byte is a CB prefix, the instruction will be decoded as stated in section 7, DDCB-prefixed opcodes. Skip to content. T. This was written in a single day, but seems to work quite well now. Langston - bbcbasic-z80/cpm. Drawing on the screen; ZX-Spectrum Assembly, Pong; Useful links; Drawing on the screen. All Z80 registers are implemented using static RAM. Byl navržen, aby byl zpětně kompatibilní s procesorem Intel 8080, takže operační systém CP/M mohl fungovat bez jakýchkoli dalších úprav. Le premier de la gamme fut le CPC 464 en 1984 , équipé d'un lecteur de cassettes intégré il se plaçait en concurrent du Commodore C64 beaucoup plus compliqué à utiliser et plus cher. General There's no direct route to that, you'll have to do it as a compound — NC to eliminate all results less than 0, getting you to greater than or equal, followed by NZ to eliminate the Using a combination of RET NZ and JP (HL) will increase the "setup time" for a loop, but reduce the iteration time since the combined execution time for RET NZ that is not DCOMPR BIOS routine will do that: compare HL with DE updating all necessary flags. io. Table of contents. If it is zero, we set D to zero, LD D, A; A is already zero. You signed out in another tab or window. You can use text, graphics, and rarely sound. Articles / Languages / assembler C++. R. As you might be able to tell, I attempted to use DE as the So I'm learning about using input and output in z80 asm, jr nz,loop ;loops until enter is pressed instead of a ret, we will draw the dot now and use the ret of Draw to return from the subroutine Draw: ;Redraw the point at the new coordinates ld d,1 X_COORD = $+1 ;this points to the second byte of the opcode ld b,47, which happens to be the 1-byte integer loaded into b Z80 5seconds Timer for 10 MHz Point: Use 3 Loops ORG 0000H LD SP,0FFFFH MAIN: CALL TIMER5 TIMER5:LD E,35H J60: LD B,0FFH J61: LD D,0FFH J62: DEC D JP NZ,J62 DEC B JP NZ,J61 DEC E JP NZ,J60 RET END note: If your system has CTC, it's better to use CTC timer interrupt. 3) Things affecting the IFFs [4] All the IFF related things are: IFF1 IFF2 /CPU reset 0 0 DI 0 0 EI 1 1 Accept INT 0 0 Accept NMI 0 - RETI/N IFF2 - All the EDxx RETI/N instructions LD A,I/LD A,R - - Copies IFF2 into P/V flag Note the fact about RETI/N: all the EDxx RET instructions copy IFF2 into IFF1, even RETI! The other one-byte RET commands FuzixOS: Because Small Is Beautiful. ) 3. Instruction mnemonics All standard Zilog mnemonics are accepted: 'ADD', 'ADC' and 'SBC', must be followed by 'A' or 'HL'. the x-coordinate is stored in D and the y-coordinate is stored in E 01110 10001 10001 When I started z80 assembly I used routines written by other people to determine screen addresses. Host and manage packages Security. clsx ld (hl), a inc hl djnz clsx add hl, de dec c A powerful Z80 based computer with an IDE disk interface and a simple operating system capable of reading FAT32 filesystems. Here are a few routines to get RET NZ RNZ: POP BC POP B: JP NZ,addr JNZ addr: JP addr JMP addr: CALL NZ addr CNZ addr: PUSH BC PUSH B: ADD n ADI n: RST 0 RST 0: RET Z RZ: RET RET: JP Z,addr JZ addr # * CALL Z addr CZ addr: CALL addr CALL addr: ADC n ACI n: RST 8 RST 1: D: RET NC RNC: POP DE POP D: JP NC,addr JNC addr: OUT A,(p) OUT port: CALL NC addr CNC addr: I'm trying to learn Z80 assembly - and forgive me if this is extremely obvious - but I'm rather new to assembly as a whole. db "Str" s_pic: . GitHub Gist: instantly share code, notes, and snippets. This provides a 5. Einsatzzweck: Standardcode: Optimierter Code: Vorteil: Hinweise & Nachteil: Unterprogrammaufruf vor Return Befehl: CALL label RET: JP label: 1 Byte 17 Takte: Schleifen: DEC B JR NZ,label: DJNZ label: 1 Byte 3 Takte: Kommt häufig vor wenn 8080 Programme auf In this chapter of ZX Spectrum Assembly, we will learn how to paint on the screen and see its layout. Contribute to wwarthen/RomWBW development by creating an account on GitHub. If not, it will be skipped. Here we add two 32-bit integers: LD HL, (word1) ; Get least-significant word of word1 LD DE, (word2) ; Get least-significant word of word2 ADD HL, DE ; Add them LD (result), HL ; Store least-significant result LD HL, (dword1 + 2) ; Get most-significant word of word1 LD DE, The CPU used by the Nintendo GameBoy is a specially modified version of the Z80, with various functions removed to make the CPU cheaper to manufacture. Der Sinclair QL erschien, ein Jahr später Atari The MEMPTR is an internal 16 bits register of the Z80 CPU which is mostly used by the CPU to perform 16 bits operations (on values or addresses). Luxen; Super-Expert (Posts: 802) ASM String comparison; 24 Nov 2014 04:57:36 pm; In assembly, to compare a string, does one really have to load each Character into A and whatev, CP, and then continue if true? is there any faster way for Instructions. Z80 Mode 2 interrupt reduces CPU's load. If the result is not zero, the two keys have not been pressed and we jump to check the 0 key press, JR NZ, scanKeys_0. Some crazy russians recently cracked the MEMPTR algorithm to understand how each CPU (Which the Z80 PIO recognises. Unknownloner; Quality over Quantity (Posts: 157) 31 May 2015 04:24:53 A rather small Z80 based computer with the following features: Z80 single board computer; IDE controller; FAT file system (currently read only) in Z80 assembler ; In September 2011 I somehow got the feeling that I just HAD to build a small Z80 based computer again. dw rdisp Recently I issued the third Z80 programming challenge for the ZX Spectrum: This time the challenge is to write the shortest code to display a masked 16×16 pixel sprite. 8 natural logs. Projects Projects Channels Channels News Contests Events Videos. Collision Detection in z80 Assembly; 31 May 2014 12:10:40 pm; For a small game i 'm making, i need a way to tell when the sprite is on the ground or when it should fall. ret ; This routine goes through the sprite logic table and runs the logic routine for each sprite Handle_Sprites: LD (Handle_Sprites_SP + 1), SP ; Clear th sort table The fourth Z80 challenge for the ZX Spectrum was issued last week: Back to something simple for the next challenge, a diagonal fade-to-white CLS. ): Z80-mbc2 Z80 Code Flash User LED: This is an example user LED program written in Z80 assembler for the z80-mbc2 computer. Leave Feedback. The state of IFF2 is copied back to IFF1 so that maskable interrupts are enabled immediately following the RETN if they were enabled before the nonmaskable interrupt. These mnemonics mimic standard ones (used in assemblers) but with some exceptions (because of ruby parser spec. wait in a, ($40) and $20 jr z, wait ret cls: ld hl, tvram ld de, 40 ld c, 25 . If the result of mathematical operation is zero the bit is set (= 1 = "Z") other ways the bit is reset (= 0 = "NZ") "Not zero" Bit 5, YF, copy of the results 5th bit. ret loadcab: ld b,128 loopcab: call lbyte jr c, loadcab cp &aa jr nz,loadcab djnz loopcab call w_bajo jp w_alto load: call lbyte ret c ld (hl),a inc hl dec de ld a,d or e jr nz,load ret lbyte: push bc ld b,8 lbuc: ex af,af' call w_bajo GitHub - toptensoftware/yazd: Yet Another Z80 Disassembler QuoteYAZD is a simple command line disassembler for Z80 binary code files. ret z ret nz ret c ret nc: ret if zero flag set ret if zero flag reset ret if carry flag set ret if carry flag reset jp addr1: jp z,addr1 jp nz,addr1 jp c,addr1 jp nc,add1: jump if zero flag set jump if zero flag reset jump if carry flag set jump if carry flag reset call addr1 ATTRIBUTE_ADR equ $5800 ENTRY_POINT equ $8000 org ENTRY_POINT start: ld hl, ATTRIBUTE_ADR ; adresa pro zápis ld b, l ; zapisovaná hodnota + počitadlo smyčky loop: ld (hl),l ; zápis hodnoty na adresu (HL) inc l ; zvýšení adresy i zapisované hodnoty djnz loop ; kombinace dec b + jp NZ, loop; snížení hodnoty počitadla; skok pokud se ještě nedosáhlo nuly ret end You signed in with another tab or window. Log in; Sign up The ultimate Amstrad CPC community! 03:58, 16 December 24. Figure 2 illustrates how this memory is configured to eighteen 8-bit registers and four 16-bit registers. The interresting part is that two bits (11 and 13) of this register seems to be copied in the bit 3 and 5 of the flag register. Tiny Basic for the Z80 Microprocessor. For testing, I used to front panel connector on the MIO card. Perform conditional dw stands for "define word". epsilon5 4 Super-Expert (Posts: 833) Running program from a hook ; 01 Jan 2021 01:44:27 pm; Recently, I've been trying to get VYSION to run when the [prgm] key is pressed, by way of a GetKey hook. 0 1 2 3 4 5 6 7 8 9 A B C D E F; 0: add ix,bc: 1: add ix,de: 2: ld ix,** ld (**),ix: inc ix: inc ixh: dec ixh: ld ixh,* add ix,ix: ld ix,(**) dec ix: inc ixl: dec ixl Z80 / R800 instruction set. If you plan to disable the BIOS, just copy the code used A flood fill is a graphical algorithm to colour an area of screen bounded by pixels of another colour. The CodeFiles project of the folder contains a Code. For example: ld b,96 ; erase all of the line disp_version_erase_loop: call _vputblank ; erase pixels at cursor (uses b reg) djnz disp_version_erase_loop ; loop Of course you can do the same I’m able to see the disassembly, I just don’t see the instructions correctly; Instead of getting 16bit-wide steps, I’m getting 8bit-wide steps. z80:Drawing Routines. The issue is that it is huge and slow, taking about 11000 t-states and being 188 bytes for the 2006 C2 00 40 JP NZ,4000 2009 C9 RET Export Z80 Assembly If the TEC is connected to a serial terminal via an FTDI to USB adaptor, code that is stored or written on the TEC can be disassembled and sent to the terminal. EDIT: It is more efficient at 32-bits, but only by little Remember, a lot of the optimized Z80 routines work well here, but some of them can actually be reworked to be even more efficient than a direct translation. This is the complete Spectrum character set, with codes in decimal and hex. . the manual: Here is a pastebin of my code. Langston - jblang/bbcbasic-z80 . This is a great way to view the code that is on the TEC in a readable format and could be passed into a Z80 compiler on a PC. dw putway . Basically DJNZ decrements the B register and jumps to a label if not zero. The ZX Spectrum’s screen, the pixel area, is located from memory address $4000 to $57FF, both inclusive, for a Z80 Assembly Instruction Set 31 May 2023. However, this application note should give you a good feel for the Z80 Family devices. 31 Dec 2015 08:38:07 am; Hey all! I'm trying to make a new program, which first installs a GetKeyHook. g. Table I Z-80 Instructions from 00 through 3F HEX OCT OP AD HEX OCT OP AD 00 000 NOP 01 001 LD BC,nn * 08 010 EX AF,AF' 09 011 ADD HL,BC * 10 020 DJNZ n 11 021 LD DE,nn * 18 030 JR n 19 031 ADD HL,DE 20 040 JR NZ,n 21 041 LD HL,nn * 28 050 JR Z,n 29 051 ADD HL,HL 30 060 JR NC,n 31 061 LD SP,nn * 38 070 JR C,n 39 071 ADD HL,SP 02 002 CP/M for the Z80 Playground that runs on the FAT disk format - skx/z80-playground-cpm-fat 📅 Last Modified: Thu, 30 Nov 2023 23:02:52 GMT. Replace the A68k CPU instructions with Z80 CPU instructions: adc add and bit call ccf cp cpd cpdr cpi cpir cpl daa dec di djnz. line in 8x8 = done ld a,l ; 4T compute L for next character line add a,32 ; 7T ld l,a ; 4T ld a,h ; 4T jr c,DOWNHL2 ; 12/7T C = transition trough one third of screen sub 8 ; 7T ld h,a ; 7T DOWNHL2 cp 88 ; 7T ret Although integer math may seem more natural for us when we program the Z80, floating point math that works with fractional numbers is not much more difficult. The most commonly used flags are the 'zero flag' and the 'carry flag', we will C ret nz pop bc jp nz,xx jp xx call nz,xx push bc add a,x rst 00h ret z ret jp z,xx CB call z,xx call xx adc a,x rst 08h D ret nc pop de jp nc,xx out (x),a call nc,xx push de sub x rst 10h ret c exx jp A guide to using the new range of retro-inspired 8080/Z80 based computers. Contribute to joelang/z80-sbc development by creating an account on GitHub. Bit 4, HF, "Half-carry" from bit 3 to 4. Automate any Let’s compare the speed of this loop with a ‘common’ 16-bit loop. Find and fix vulnerabilities Codespaces. assembler. I have familiarised myself with how jumps work after making a comparison with cp and how they equate to things I know, that NZ is the equivilant of "!=", C correlates to "<" and so on. 4mhz signal from the RC2014 clock module directly into the VIA or inverted works. Z80 single board computer with CP/M 2. Xeda112358; Expert (Posts: 623) Fixed Point Logarithm; 20 May 2013 07:53:49 am ; Hey everyone, I wrote a routine for computing fixed point 8. You can find the latest release binary and source code on GitHub. However, I discovered this caused First we load the value of D in A, LD A, D, and check if the value is three, SUB $03, in which case both keys would have been pressed. The emulator handles all (officially) undocumented instructions, You can see this code tests if the RET NZ operation works correctly with the Z flag set to 0. These eight status are defined in the following table, which also RET FUNCTIONS CALL Call allowsyou to jump to a different location in the ASM program, while saving whereit was, so it can return to that location later. 7 7654_3210 i Операнды Такты t+ Заметки; Основной набор; 00_000_000: nop: 4: 1: 00_001_000: ex: af,af' 4: 1: 00_010_000: djnz * 13/8: 1: 00_011_000 » Forum > Calculator Programming > z80 & ez80 Assembly. Quote . Jump to navigation Jump to search. Ben Hanson. Navigation Menu Toggle navigation. clsx ld (hl), a inc hl djnz clsx add hl, de dec c You signed in with another tab or window. Bit 2, PF/VF, Parity flag. this is the sprite and the program should test for the two fields on the bottom left and bottom right of the sprite. Das eBook Angewandte Mikroelektronik wurde von Hans Lohninger zur Unterstützung verschiedener Lehrveranstaltungen geschrieben. L'Amstrad CPC est une machine 8 bits à base d'un Z80 à 4MHz. x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF 0x: RLC (IX+d) RRC (IX+d) 1x: RL (IX+d) RR (IX+d) ;turn the pixel ON call GetPixelLoc ret nc or (hl) ld (hl),a ret ;turn the pixel OFF call GetPixelLoc ret nc cpl ;invert the bits of A and (hl) ld (hl),a ret ;invert the pixel call GetPixelLoc ret nc xor (hl) ret ;test the pixel (nz=ON, z=Off) call GetPixelLoc ret nc ;also happens to For testing, I used to front panel connector on the MIO card. Along with the technical Manual, Product Specification and some other application Shrinkler Z80 decrunch routine - Page 2. This opcode map collates the references into a coherent Quite some time ago, in October 2011, I built a simple Z80 based computer with an IDE interface, embedded Forth interpreter etc. Let's learn some basic instructions you can use in your programs DOWNHL inc h ; 4T inc h works only on first 7 pixel lines ld a,h ; 4T on character line and 7 ; 7T ret nz ; 11/5T NZ = wasn't last px. Z80 5seconds Timer for 10 MHz Point: Use 3 Loops ORG 0000H LD SP,0FFFFH MAIN: CALL TIMER5 TIMER5:LD E,35H J60: LD B,0FFH J61: LD D,0FFH J62: DEC D JP NZ,J62 DEC B JP NZ,J61 DEC E JP NZ,J60 RET END note: If your system has CTC, it's better to use CTC timer interrupt. Either way, check out the example: EDIT: Updated to define if there is padding above the text or not. Reply to topic » » View previous topic:: View next topic . The routine should be called with the address of the sprite data in one register and the X and Y screen coordinates in another. Russell's BBC BASIC for Z80, with additional features by J. This assembler is similar to the 6502 assembler on the BBC Micro and it is entered in the same way. The 5. You can create functions that perform certain tasks,and even accept input and produce output. First a simple and small to show. Log in Sign up. Python Zilog Z80 CPU Emulator. 2: Livestream & Giveaway Drawing. Start 2) It means that the return instruction will only be executed if the zero flag is set. Thus I decided to reimplement it and design a real printed circuit board using RET nz POP BC JP nz,ad JP ad CALL nz,ad PUSH BC ADD A,v RST 0h RET z RET JP z,ad * CALL z,ad CALL ad ADC A,v RST 8h D0 RET nc POP DE JP nc,ad OUT (v),A CALL nc,ad PUSH DE SUB v RST 10h RET c EXX JP c,ad IN A,(v) CALL c,ad ** SBC A,v RST 18h E0 RET po POP HL JP po,ad EX (SP),HL CALL po,ad PUSH HL AND v RST 20h RET pe ret nz set 0,b 193 C1 pop bc set 0,c 194 C2 jp nz,nnnn set 0,d 195 C3 jp nnnn set 0,e 196 C4 call nz,nnnn set 0,h 197 C5 push bc set 0,l 198 C6 add a,nn set 0,(hl) 199 C7 rst 00h set 0,a 200 C8 ret z set 1,b 201 C9 ret set 1,c 202 CA jp z,nnnn set 1,d 203 CB CB set 1,e 204 CC call z,nnnn set 1,h 205 CD call nnnn set 1,l 206 CE adc a,nn set 1,(hl) The scanline technique is a fast, stack-efficient flood fill which can be implemented in 99 bytes of Z80, as demonstrated below: ; scanline fill by John Metcalf ; call with d=x-coord, e=y-coord ; set end marker fill: ld l,255 push hl ; calculate bit position of pixel nextrun: ld a,d and 7 inc a ld b,a ld a,1 bitpos: rrca djnz bitpos ld c,b ld b,a ; move left until hitting a set pixel or the 1 Z80命令説明書 [はじめに] Z80はザイログ社が開発した8ビットCPUで、8080（インテル社）の命令の全てを含み、さらにその上全く新しい多くの命令を実行 $DDCB List. Z80 Mnemonic Description Example Parameters Flags affected ADC r Add register r RET Return from a subroutine. It is written for . MEMPTR - redcode/Z80 GitHub Wiki Simple and small routines that print the value of z80 register pair hl. Enjoy . Along with the technical Manual, Product Specification and some other application ld a,h or l dec hl ret z inc hl push hl ld b,15 add hl,hl jr c,$+4 djnz $-3 ld a,b sub 8 jr nc,$+4 neg ld b,a pop hl push af jr nz,lnx jr nc,$+7 add hl,hl djnz $-1 jr lnx sra h rr l djnz $-4 lnx: dec h ;subtract 1 so that we are doing ln((x-1)+1) = ln(x) push hl ;save for later add hl,hl ;we are doing the 4x/(4+4x) part add hl,hl ld d,h ld e,l Contribute to cburbridge/z80 development by creating an account on GitHub. z80 5seconds timer for 10 mhz org 0000h ld sp,0ffffh main: call timer5timer5:ld e,35hj60: ld b,0ffhj61: ld d,0ffhj62: dec d jp nz,j62 dec b jp nz,j61 dec e jp nz,j60 ret end Aber noch nicht ausprobiert. For Z80 timing You signed in with another tab or window. org #8000 ld a,2 out (#fe),a jp #12a2 In Solution Explorer, right-click the Code. 4) Sounds all correct to me! The logical instructions clear the carry flag unconditionally. Die ersten 16 Bit Rechner rückten in bezahlbare Regionen vor. Bit 3, XF, copy of the results 3rd bit. ; The routine disassembles a single Z80 instruction at address DE. The conditions work the same way as above, all of them can be used. This will be a living document that I will update as I find errors questionsabout the Zilog Z80 Family. Automate any workflow Codespaces. As you are probably aware if you understand these things, certain Z80 instructions are compounds starting with CBh or EDh; the two right So, you want to optimize your assembler code a little bit ? Here are some "generic" ways to speed up / shorten your Z80 progs a little bit: CP 0 -> OR A Collision Detection in z80 Assembly; 31 May 2014 12:10:40 pm; For a small game i 'm making, i need a way to tell when the sprite is on the ground or when it should fall. You signed in with another tab or window. I invert the Z80 RD signal and feed it into the 65C22 r/W pin. You might want to search the sources for the call of CheckOnWater to check whether the carry flag ret nz -: ld a,(hl) \ inc hl cp 255 jr nz,{+} add a,c jr nc,$+3 inc b ld c,a jr {-} +: add a,c jr nc,$+3 inc b I had another Z80 LZ4 decompressor (made by someone from the ZX Spectrum scene), but can't find it now in the garbage pile that is my hard drive. Automate any workflow Packages. The following code can convert a number to BCD, and display it. the Stack Pointer contains $2002 and the Program Counter contains $18B5, thereby pointing to the address of the next program op code to be fetched. This machine is described in more detail here. News: Printed Amstrad Addict magazine announced, check it out here! Main Menu. I did this a test and revision exercise for me, this is my first Z80 program for over 35 years. Thread ignore; Dierch-Jentz. RET is used mostly for exiting an assembly program or returning from a routine. I believe I was doing this because of some bad advice. YAZD supports the following: Disassembly of all Z80 instructions, as supported by z80ex. BIT, CALL, CP, CPD, CPDR, CPI, CPIR, RETI, RETN. Z80 se objevil, když Federico Faggin po práci na procesoru Intel 8080 opustil společnost Intel a na konci roku 1974 vstoupil do firmy Zilog. Contribute to EtchedPixels/FUZIX development by creating an account on GitHub. I invert it more to buffer it bit 6, ZF, Zero flag. Branch Control/Program Counter Load Instructions; 8080 Mnemonic Z80 Mnemonic Machine Code Operation; JMP: address: JP: address: C3address: PC <- address: JNZ: address 0 1 2 3 4 5 6 7 8 9 A B C D E F; 0: add ix,bc: 1: add ix,de: 2: ld ix,** ld (**),ix: inc ix: inc ixh: dec ixh: ld ixh,* add ix,ix: ld ix,(**) dec ix: inc ixl: dec ixl 0: 1: 2: 3: 4: 5: 6: 7: 8: 9: 0a: 0b: 0c: 0d: 0e: 0f: 0: nop: ld bc,n'n: ld (bc),a: inc bc: inc b: dec b: ld b,n: rlca: ex af,af' add hl,bc: ld a,(bc) dec bc: inc c You signed in with another tab or window. BBC BASIC for the Z80 CPU. 738Mhz signal for the video chip, and boosted the Z80 clock speed over fivefold from the original ~1Mhz the 555-timer based clock. One method for displaying numbers larger than 16 bits is to convert it to Binary Coded Decimal (BCD) first, and display the result. It is a convenience directive for defining least significant byte first two byte words, as the Z80 uses them. As far as commands go, that's most of it indeed; you'll get the job done (usually). I am trying to code this program, similar to game: "The Typing of The Dead" in Amstrad CPC 464 using Assembly language for the Z80 processor. They are divided into following sections: Z80 CPU Z80 DMA Z80 PIO Z80 CTC SIC), Z80 DART Obviously, not every questions on Z80 Family components are answered. Mostly for debugging or simple programs. With text, the OS offers us many tools and it doesn't need to be too fast, but with graphics, the OS routines often do not do the job. All gists Back to GitHub Sign in Sign up Sign in Sign up You signed in with another tab or window. RETN - - - - - - RL r Rotate bits in register r Left with To create your first Z80 assembly program, follow these steps: Create a new ZX Spectrum 48 project (see details here). Part one of this section describes how to program the SIO so that it communicates with a PC in asynchronous terminal mode whereas part two focuses on the block transfer mode used for file transmission. Integer Math Addition/Subtraction. The program consists in when you see a string of characters like a word in the screen in Z80, Z180, Z280, Z380, Programming, Hardware, Software, Utilities, FAQ, Support, CPU, assembler It seems to be that on the z80, this method blows away long division when using a floating point storage format. Contribute to cburbridge/z80 development by creating an account on GitHub. 37Mhz clock signal for the Z80, along with a 10. Look at the upper 32K of memory, for instance the UDG graphics. Other timings cc condition code (z,nz,c,nc,p,m,po,pe) Z80 Mnemonic Description Example Parameters Flags affected ADC r Add register r RET Return from a subroutine. This is basically a pop pc. labels; comments; ld; call; cp; add; sub; inc; dec; djnz; jr; jp; ret. LIFE SUPPORT POLICY ZILOG’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS PRIOR WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF ZILOG » Forum > Calculator Programming > z80 & ez80 Assembly. To make sure that I understand how everything works I’ve gone through all of the instructions and made notes on how they work. 4) Sounds all correct to me! Z80 CPC Timings cheat sheet - Introduction Page 1 Z80 timings on Amstrad CPC - Cheat sheet Instruction timings. My last homebrew Z80 was built when I was still in school (more than 20 years ago) and somehow I felt a bit nostalgic BBC BASIC (Z80) includes a Z80 assembler. Kurze Übersicht über die Befehle des Z80 Abkürzungen: r,r’ - - Das Komplement steht im Zero - Flag. None of the ret instructions change a flag. Write better code with AI Code review. Of course, I’m It supports both the classic Z80 and the eZ80. HL is set to 0 and is incremented on a loop and then the loops calls CP_HL_DE and checks to see if HL equals DE. ; It was originally developed for CP/M on an Amstrad CPC128. CPU features: Supports eZ80 CPU Supports classic Z80 CPU Select ADL and non-ADL modes; Input and output options: By default, reads input hexadecimal to disassemble from command » Forum > Calculator Programming > z80 & ez80 Assembly. 4. RETI - - - - - - RETN Return from a non maskable interrupt (NMI). This is an overview of the Z80 instruction set, including undocumented instructions and the R800 MULUB and MULUW instructions. You know ld, cp and jp, and think that's all. Joined: May 20th 2015. 5. (in assembly we don't usually talk about signed/unsigned. The 6502 instructions for the Z80 The scanline technique is a fast, stack-efficient flood fill which can be implemented in 99 bytes of Z80, as demonstrated below: ; scanline fill by John Metcalf ; call with d=x-coord, e=y-coord ; set end marker fill: ld l,255 push hl ; calculate bit position of pixel nextrun: ld a,d and 7 inc a ld b,a ld a,1 bitpos: rrca djnz bitpos ld c,b ld b,a ; move left until hitting a set pixel or the Z80, Z180, Z280, Z380, Programming, Hardware, Software, Utilities, FAQ, Support, CPU, assembler Z80 (8080) Code Instruction Set . I'll post it here if I manage to dig it up. dw saveshad . code. dec a \ ret nz \ ld l,$61 ret s_str: . I invert the clock signal too and send it straight to the via. Let's say 1000. Sign in Z80-Retro. Plan and track work . If you press Y=, the equation editor, I wanna run prgmU, but this doesn't seems An algorithmic approach to decoding z80 instructions stored in memory, for use in disassemblers and emulators. ld a,5 Contribute to bchiha/Tiny-Basic-Z80 development by creating an account on GitHub. Automate any org 32768 di ld b,0 l1: xor a ld r,a dec hl ld a,h or l jr nz,l1 djnz l1 ei ret It will take about three minutes to run. » Forum > Calculator Programming > z80 & ez80 Assembly. Decimal Unsigned Versions . 3) Yes, and yes. Find and fix here is a list of how many clockcycles the z80 instructions take. RET cc (where cc=c,nc,z,nz,p,m,pe,or po) If cc is true then the ret is executed. RETI is also decoded by the Z80 peripheral chips (SIO, CTC, PIO, DMA) and tells them ret z returns with a cleared C (caused by sub WATER_TITLE), because the result of the subtraction is zero. 5MHz. Speed on the Z80 is measured in T-states, also known as clock ticks or cycles. cc is condition: NZ, Z, NC, C, PO, PE, P, M. Introduction: Z80-mbc2 Z80 Code RET NZ: 11/5: 1 : C0 : If Zero = 0 (non-zero) RET PE: 11/5: 1 : E8 : If Parity = 1 (even) RET PO: 11/5: 1 : E0 : If Parity = 0 (odd) RETI: 14: 2-----ED 4D: Return from Interrupt: PC=(SP)+ RETN: 14: 2-----ED 45: Return from NMI: PC=(SP)+ RLA: 4: 1--0-0* 17: Rotate Left Accumulator: A={CY,A}<-RL r: 8: 2 **0P0* CB 10+r: Rotate Left: m={CY,m}<-RL (HL) 15: 2 : CB 16 : RL (IX+d) 23: 4 : You know, when disassembling a Z80 binary, you'll often get nonsense like this: LBFF9: CP 00h RET NZ RRA JP NZ,LC000 LC000: LD DE,0C136h When in fact that should be: DB 0FEh DW 0C000h DW 0C21Fh DW 0C000h LC000: LD DE,0C136h RET. Multiple expressions, separated by commas, may be specified. RET Z 'c': c m nc nz p po pe z - - - - - - RETI Return from an interrupt. Here is a d33f 78 LD A,B d340 B1 OR C d341 C22BD3 JP NZ,D32Bh d344 7A LD A,D d345 B3 OR E d346 1B DEC DE d347 00 NOP d348 00 NOP d349 C22BD3 JP NZ,D32B d34c C9 RET Now, instead of stopping where it should, it goes on to corrupt memory further until it reaches d325 and causes the script to crash. Contribute to rtrussell/BBCZ80 development by creating an account on GitHub. Find and fix vulnerabilities Actions. 1) and supports all of the published (legal) instructions of the Z80 processor, as well as most of the unpublished (illegal) operations. This instruction is used at the end of a nonmaskable interrupts service routine to restore the contents of the Program Counter (analogous to the RET instruction). It gives access to the I2C bus as well as 8 GPIO pins, connected to the Z80 PIO. The 6502 instructions JSR and RET work with a stack a bit differently than the Z80 instructions CALL and RET; The 6502 has nothing similar to the Z80 instructions HALT, RETN and IM or to registers R and I; The Z80 instruction RETI is unique in the processor world; The 6502 doesn't have a special address space for input and output. It might be faster. Contribute to adzierzanowski/zasm development by creating an account on GitHub. You can CALL it or even RST it. Manage RET TextInverseOff: RES TextInverse, (IY + TextFlags) RET MenuSkipOptions: LD A, (HL) INC HL OR A JR NZ, MenuSkipOptions INC HL INC HL ;Skip labelbytes. x0 : x1 : x2 : x3 : x4 : x5 : x6 : x7 : x8 : x9 : xA : xB : xC : xD : xE : xF : 0x *NOP 2 8-----*NOP 2 8-----*NOP 2 8-----*NOP 2 8-----*NOP I am having a bit of trouble with writing some Z80 code and while I have written some code before, it's been a while and I'm still quite uncomfortable with Z80 as compared to 6502. Here is the way it works-- If my numbers are always normalised (this means the upper bit is always set, unless the number is 0), then I might want something like the following in hexadecimal 8AD176/AC0980 (in base 10, 9097590/11274624). There's no need to set the screen attributes. Z80 Color Mandelbrot. So what I'm doing is, in my actual code I've set DE to some number. PT_ 3 Site Admin (Posts: 2088) Run BASIC program with hook. ret; =====; DIS-Z80 was published in the SUBSET column of Personal Computer World 1987. ) The following code has been replaced. To do addition or subtraction on an integer of arbitrary size, we use ADC. Welcome to CPCWiki forum. It's based on the disassembler in z80ex, ported to C#. db "Pic" s_GDB: . 5. Back in 1984, I wanted to write a Z80 assembler. Since the overall system occupies a 10 inch enclosure and is completely wire-wrapped it is not as portable as I wished it was. clsy ld b, 80 . media post, oauth) only. ;Number in hl to decimal ASCII ;Thanks to z80 Bits ;inputs: hl = number to ASCII ;example: hl=300 outputs '00300' ;destroys: af, bc, hl, de used DispHL: ld bc,-10000 call Num1 ld bc,-1000 call Num1 ld bc,-100 All the EDxx RET? instructions copy IFF2 to IFF1, even RETI (ED4D), which the official documentation does not note. At the time, this would have meant coding it in Z80 machine code, but due to the conveniences of modern technology, I have now done it in C++. miningdudebro; Newbie (Posts: 11) Are there any better optimized routines for filling the screen? (ez80) 13 Nov 2024 08:05:08 pm; Code: ld d, 0 call fillScreen ret fillScreen: ld hl, vRam ld bc, 76800 fillScreenLoop: ld (hl), d inc hl dec bc jp nz, » Forum > Calculator Programming > z80 & ez80 Assembly. RETN - - - - - - RL r Rotate bits in register r Left with An open source Z80 computer suitable for running CP/M and embedded applications - Z80 Retro! Skip to content. 1,279. It’s currently written to convert a 24 bit number to a 10 digit BCD number, but can be ret nc 2/4 d0 ret nz 2/4 c0 ret p 2/4 f0 ret pe 2/4 e8 ret po 2/4 e0 ret z 2/4 c8 reti; instruction nops bytes; reti: 4 ed 4d retn; instruction nops bytes; retn: 4 ed 45 rl; instruction nops bytes; rl (hl) 4 cb 16 rl (ix+nn) 7 dd cb nn 16 rl (iy+nn) 7 fd cb nn 16 rl a 2 cb 17 rl b 2 cb 10 rl c 2 cb 11 rl d 2 cb 12 rl e 2 cb 13 rl h 2 cb 14 rl l 2 cb 15 rla; instruction nops bytes; rla: 1 17 ATTRIBUTE_ADR equ $5800 ENTRY_POINT equ $8000 org ENTRY_POINT start: ld hl, ATTRIBUTE_ADR ; adresa pro zápis ld b, l ; zapisovaná hodnota + počitadlo smyčky loop: ld (hl),l ; zápis hodnoty na adresu (HL) inc l ; zvýšení adresy i zapisované hodnoty djnz loop ; kombinace dec b + jp NZ, loop; snížení hodnoty počitadla; skok pokud se ještě nedosáhlo nuly ret end dec a \ ret nz \ ld l,$61 ret s_str: . CC isOPTIONAL back to list of instructions FUNCTIONS Putting theCALL and RET commands together you are given a powerful way to modulateyour programs. ds stands for "define space". A commonly used routine is 'Move register pair down one pixel line'. For more information on undocument instructions, refer to Sean Young’s extensive The Undocumented Z80 Documented (). z80asm file:; Code file start: . RET - - - - - - RET c Return from a subroutine only if condition c is true. I used to use it to gate the VIA with one of it's chip select pins. Here's my WIP code: ld hl,C000 21 00 C0 ld a,(hl) 7E jr nz 20 0A What I'm trying to do is have the code jump when A doesn't equal 0 ala BNE. Plan and track work Code Review. vuocqxa zkfm pocn ncuud wztnoif fxl mpi tdikx snc epvm
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