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TheZ80 library implements a fast, small and accurateemulator of theZilog Z80. It emulates all that is known to date about this CPU, including the undocumented behaviors,MEMPTR,Q and thespecial RESET. It also has the honor of having been the first open-source project to provide full emulation of the interrupt mode 0.

The source code is written inANSI C for maximum portability and is extensively commented. The aim has been to write a well-structured, easy-to-understand piece of software; something solid and elegant that canstand the test of time with no need for major changes.

This Z80 CPU emulator has a classic design with instruction-level granularity that delivers the best performance, whilst offering a reasonable flexibility to achieveprecision down to the T-state level.

Instruction-level granularity implies that, except in a few well-defined cases, the execution of a given instruction cannot stop until all its internal M-cycles have been processed (i.e., instructions are not divided into micro-operations). Moreover, registers are modified only once per instruction and theT-state counter is normally updated after a full instruction has been executed.

That said, instructions, flags, memory accesses, interrupts, clock cycles, etc., are accurately emulated according to the availabletechnical documentation, the findings made after decades of research on the Z80 andelectronic simulations. And, of course, the emulator passes the most exhaustivetests written to date, including all three major test suites:

This set of programs is intended to help the emulator authors to reach the desired level of the CPU emulation authenticity. Each of the included programs performs an exhaustive computation using each of the tested Z80 instructions, compares the results with values obtained from a realSinclair ZX Spectrum 48K with Zilog Z80 CPU, and reports any deviations detected.

Results (v1.0)

z80full.tap Tests all flags and registers.	z80doc.tap Tests all registers, but only officially documented flags.
z80flags.tap Tests all flags, ignores registers.	z80docflags.tap Tests documented flags only, ignores registers.
z80ccf.tap Tests all flags after executingccf after each instruction tested.	z80memptr.tap Tests all flags after executingbit N,(hl) after each instruction tested.

Results (v1.2a)

z80full.tap Tests all flags and registers.	z80doc.tap Tests all registers, but only officially documented flags.
z80flags.tap Tests all flags, ignores registers.	z80docflags.tap Tests documented flags only, ignores registers.
z80ccf.tap Tests all flags after executingccf after each instruction tested.	z80memptr.tap Tests all flags after executingbit N,(hl) after each instruction tested.

This suite performs a series of tests to verify the MEMPTR documents^{(English,Russian)}, which are spot on, as well as a brief run through several of theCBh/DDh/FDh opcode ranges. The test results in the program are compared against those from aNEC D780C-1 CPU, but Simon Conway kindly tested several other Z80 clones, confirming the same results.

Results

z80tests.tap

Frank Cringle'sZ80 Instruction Set Exerciser attempts to execute every Z80 opcode, putting them through a cycle of tests and comparing the results to actual results from running the code on a real Z80. The exerciser is supplied with Frank's Yaze (Yet Another Z80 Emulator). It is often difficult to track down, soJonathan Graham Harston put it togetherhere, as well assome conversions. The latest release of Yaze is available atAndreas Gerlich's website.

Results (Jonathan Graham Harston's version)

zexdoc.tap Tests officially documented flag effects.	zexall.tap Tests all flag changes.

Results (Jan Bobrowski's version)

zexfix.tap Tests all flag changes.	zexbit.tap Tests all flag changes of thebit instructions.

Results (Patrik Rak's version)

zexall2.tap

First, add thezxe repository and update the package index:

sudo mkdir -pm700 /root/.gnupgsudo mkdir -pm755 /etc/apt/keyringssudo gpg --no-default-keyring --keyring /etc/apt/keyrings/zxe-archive-keyring.gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys FE214A38D6A0C01D9AF514EE841EA3BD3A7E1487echo"deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/zxe-archive-keyring.gpg] https://zxe.io/repos/apt stable main"| sudo tee /etc/apt/sources.list.d/zxe.listsudo apt update

Next, install the library package:

sudo apt install libz80

In case you need to build software that requires the Z80 library, install the development package too:

sudo apt install libz80-dev

First, add and sync thezxe overlay:

eselect repository add zxe git https://github.com/redcode/zxe-gentoo-overlay.gitemaint sync --repo zxe

Then install the library:

emerge emulation-libs/z80

brew install redcode/zxe/z80

Pre-built binaries for Windows are available on thedownload page.

You will needCMake v3.14 or later to build the package and, optionally, recent versions ofDoxygen,Sphinx andBreathe to compile the documentation. Also, make sure that you haveLaTeX with PDF support installed on your system if you want to generate the documentation in PDF format.

The Z80 library requires some types and macros included inZeta, aheader-only, dependency-free library used for portability reasons. Install Zeta or extract itssource code tarball to the root directory of the Z80 project or its parent directory. Zeta is the sole dependency; the emulator does not depend on theC standard library.

Lastly, the package includes two testing tools, which are optional to build. The first one runs various Z80-specific tests forCP/M andZX Spectrum, and will uselibzip andzlib if they are available on your system. The second tool is forunit tests in JSON format and requires thecJSON andZ80InsnClock libraries.

Once the prerequisites are met, create a directory and runcmake from there to prepare the build system:

mkdir buildcd buildcmake [options]<Z80-project-directory>

The resulting build files can be configured by passing options tocmake. To show a complete list of those available along with their current settings, type the following:

cmake -LAH -N -B.

If in doubt, read theCMake documentation for more information on configuration options. The following are some of the most relevant standard options of CMake:

• -DBUILD_SHARED_LIBS=(YES|NO)
  Generate shared libraries rather than static libraries.
  The default isNO.

• -DCMAKE_BUILD_TYPE=(Debug|Release|RelWithDebInfo|MinSizeRel)
  Choose the type of build (configuration) to generate.
  The default isRelease.

• -DCMAKE_INSTALL_NAME_DIR="<path>"
  Specify thedirectory portion of thedynamic library install name on Apple platforms (for installed shared libraries).
  Not defined by default.

• -DCMAKE_INSTALL_PREFIX="<path>"
  Specify the installation prefix.
  The default is"/usr/local" (onUNIX andUNIX-like operating systems).

Package-specific options are prefixed withZ80_ and can be divided into two groups. The first one controls aspects not related to the source code of the library:

• -DZ80_DEPOT_LOCATION="<location>"
  Specify the directory or URL of the depot containing the test files (i.e., the firmware and software required by thetest-Z80 tool).
  The default is"http://zxe.io/depot".

• -DZ80_FETCH_TEST_FILES=(YES|NO)
  IfZ80_WITH_TESTING_TOOL isYES, copy or download the test files from the depot to the build directory.
  The default isNO.

• -DZ80_INSTALL_CMAKEDIR="<path>"
  Specify the directory in which to install the CMakeconfig-file package.
  The default is"${CMAKE_INSTALL_LIBDIR}/cmake/Z80".

• -DZ80_INSTALL_PKGCONFIGDIR="<path>"
  Specify the directory in which to install thepkg-configfile.
  The default is"${CMAKE_INSTALL_LIBDIR}/pkgconfig".

• -DZ80_NOSTDLIB_FLAGS=(Auto|"[<flag>[;<flag>...]]")
  Specify the linker flags used to avoid linking against system libraries.
  The default isAuto (autoconfigure flags). If you get linker errors, set this option to"".

• -DZ80_OBJECT_LIBS=(YES|NO)
  Build the emulator as anobject library.
  This option takes precedence overBUILD_SHARED_LIBS andZ80_SHARED_LIBS. If enabled, the build system will ignoreZ80_WITH_CMAKE_SUPPORT andZ80_WITH_PKGCONFIG_SUPPORT, as no libraries or support files will be installed.
  The default isNO.

• -DZ80_SHARED_LIBS=(YES|NO)
  Build the emulator as a shared library, rather than static.
  This option takes precedence overBUILD_SHARED_LIBS.
  Not defined by default.

• -DZ80_SPHINX_HTML_THEME="[<name>]"
  Specify the Sphinx theme for the documentation in HTML format.
  The default is"" (use the default theme).

• -DZ80_WITH_CMAKE_SUPPORT=(YES|NO)
  Generate and install the CMakeconfig-file package.
  The default isNO.

• -DZ80_WITH_HTML_DOCUMENTATION=(YES|NO)
  Build and install the documentation in HTML format.
  It requires Doxygen, Sphinx and Breathe.
  The default isNO.

• -DZ80_WITH_PDF_DOCUMENTATION=(YES|NO)
  Build and install the documentation in PDF format.
  It requires Doxygen, Sphinx, Breathe, and LaTeX with PDF support.
  The default isNO.

• -DZ80_WITH_PKGCONFIG_SUPPORT=(YES|NO)
  Generate and install thepkg-configfile.
  The default isNO.

• -DZ80_WITH_STANDARD_DOCUMENTS=(YES|NO)
  Install the standard text documents distributed with the package:AUTHORS,COPYING,COPYING.LESSER,HISTORY,README andTHANKS.
  The default isNO.

• -DZ80_WITH_STEP_TESTING_TOOL=(YES|NO)
  Buildstep-test-Z80, a tool forunit tests in JSON format.
  It requires cJSON and Z80InsnClock.
  The default isNO.

• -DZ80_WITH_TESTING_TOOL=(YES|NO)
  Buildtest-Z80, a tool that runs various Z80-specific tests forCP/M andZX Spectrum.
  The default isNO.

The second group of package-specific options configures the source code of the library by predefining macros that enableoptional features:

• -DZ80_WITH_EXECUTE=(YES|NO)
  Build the implementation of thez80_execute function.
  The default isNO.

• -DZ80_WITH_FULL_IM0=(YES|NO)
  Build the full implementation of the interrupt mode 0 rather than the reduced one.
  The default isNO.

• -DZ80_WITH_IM0_RETX_NOTIFICATIONS=(YES|NO)
  Enable optional notifications for anyreti orretn instruction executed during the interrupt mode 0 response.
  The default isNO.

• -DZ80_WITH_PARITY_COMPUTATION=(YES|NO)
  Enable actual parity calculation for the P/V flag instead of using a table of precomputed values (NOT RECOMMENDED for production builds).
  The default isNO.

• -DZ80_WITH_PRECOMPUTED_DAA=(YES|NO)
  Use a table of precomputed values to emulate thedaa instruction (NOT RECOMMENDED for production builds).
  The default isNO.

• -DZ80_WITH_Q=(YES|NO)
  Build the implementation ofQ.
  The default isNO.

• -DZ80_WITH_SPECIAL_RESET=(YES|NO)
  Build the implementation of thespecial RESET.
  The default isNO.

• -DZ80_WITH_UNOFFICIAL_RETI=(YES|NO)
  Configure the undocumented instructionsED5Dh,ED6Dh andED7Dh asreti instead ofretn.
  The default isNO.

• -DZ80_WITH_ZILOG_NMOS_LD_A_IR_BUG=(YES|NO)
  Build the implementation of the bug affecting the Zilog Z80 NMOS, which causes the P/V flag to be reset when a maskable interrupt is accepted during the execution of theld a,{i|r} instructions.
  The default isNO.

Package maintainers are encouraged to use at least the following options for the shared library:

-DZ80_WITH_EXECUTE=YES-DZ80_WITH_FULL_IM0=YES-DZ80_WITH_IM0_RETX_NOTIFICATIONS=YES-DZ80_WITH_Q=YES-DZ80_WITH_ZILOG_NMOS_LD_A_IR_BUG=YES

Finally, once the build system is configured according to your needs, build and install the package:

cmake --build. [--config (Debug|Release|RelWithDebInfo|MinSizeRel)]cmake --install. [--config<configuration>] [--strip]

The--config option is only necessary for thoseCMake generators that ignoreCMAKE_BUILD_TYPE (e.g., Xcode and Visual Studio). Use--strip to remove debugging information and non-public symbols when installing non-debug builds of the shared library.

Use the following to build the emulator as a shared library and install it along with the development files into$HOME/.local:

mkdir work&&cd workgit clone https://github.com/redcode/Zeta.gitgit clone https://github.com/redcode/Z80.gitcd Zetamkdir build&&cd buildcmake \-DCMAKE_BUILD_TYPE=Release \-DCMAKE_INSTALL_PREFIX="$HOME/.local" \-DZeta_WITH_CMAKE_SUPPORT=YES \-DZeta_WITH_PKGCONFIG_SUPPORT=YES \..cmake --install. --config Releasecd ../../Z80mkdir build&&cd buildcmake \-DBUILD_SHARED_LIBS=YES \-DCMAKE_BUILD_TYPE=Release \-DCMAKE_INSTALL_NAME_DIR="$HOME/.local/lib" \-DCMAKE_INSTALL_PREFIX="$HOME/.local" \-DZ80_WITH_CMAKE_SUPPORT=YES \-DZ80_WITH_PKGCONFIG_SUPPORT=YES \-DZ80_WITH_EXECUTE=YES \-DZ80_WITH_FULL_IM0=YES \-DZ80_WITH_IM0_RETX_NOTIFICATIONS=YES \-DZ80_WITH_Q=YES \-DZ80_WITH_ZILOG_NMOS_LD_A_IR_BUG=YES \..cmake --build. --config Releasecmake --install. --config Release --strip

^{build-and-install-Z80.sh}

The package includes a tool calledtest-Z80 that runs the most relevantCP/M andZX Spectrum versions of themajor test suites. Configure the build system with-DZ80_WITH_TESTING_TOOL=YES to enable its compilation and-DZ80_FETCH_TEST_FILES=YES to download the firmware and software required. Also note that the Z80 library must be built with-DZ80_WITH_Q=YES to be able to passPatrik Rak's tests.

Once you have built the package, type the following to run all tests:

./test-Z80 -p depot/firmware -p depot/software/POSIX -p"depot/software/ZX Spectrum" -a

The tool supports options and can run the tests individually (type./test-Z80 -h for help). If you prefer to run all tests throughCTest, use this command:

ctest --verbose --build-config (Debug|Release|RelWithDebInfo|MinSizeRel)

The complete logs generated bytest-Z80 emulating different CPU variants are available here:

• Zilog NMOS
• Zilog CMOS
• NEC NMOS
• ST CMOS

Use the following to build and test the emulator:

mkdir work&&cd workgit clone https://github.com/redcode/Zeta.gitgit clone https://github.com/redcode/Z80.gitcd Z80mkdir build&&cd buildcmake \-DCMAKE_BUILD_TYPE=Release \-DZ80_FETCH_TEST_FILES=YES \-DZ80_WITH_TESTING_TOOL=YES \-DZ80_WITH_EXECUTE=YES \-DZ80_WITH_FULL_IM0=YES \-DZ80_WITH_IM0_RETX_NOTIFICATIONS=YES \-DZ80_WITH_Q=YES \-DZ80_WITH_ZILOG_NMOS_LD_A_IR_BUG=YES \..cmake --build. --config Releasectest --verbose --build-config Release

^{build-and-test-Z80.sh    build-and-test-Z80.bat}

The Z80 libraryincludes aconfig-file package for integration into CMake-based projects that must be installed for development. Usefind_package to find theZ80 package. This creates theZ80 imported library target, which carries the necessary transitive link dependencies. Optionally, the linking method can be selected by specifying either theShared orStatic component.

Example:

find_package(Z80 REQUIRED Shared)target_link_libraries(your-target Z80)

When not specified as a component, the linking method is selected according toZ80_SHARED_LIBS. If this option is not defined, the config-file uses the type of library that is installed on the system and, if it finds both the shared and the static versions,BUILD_SHARED_LIBS determines which one to link against.

To embed the Z80 library as a CMake subproject, extract the source code tarballs ofZeta andZ80 (or clone their respective repositories) into a subdirectory of another project. Then useadd_subdirectory in the parent project to add the Z80 source code tree to the build process (N.B., the Z80 subproject will automatically find Zeta and import it as aninterface library).

It is advisable to configure the Z80 library in theCMakeLists.txt of the parent project. This will eliminate the need for the user to specifyconfiguration options for the Z80 subproject through the command line when building the main project.

Example:

set(Z80_SHARED_LIBSNOCACHEBOOL"")set(Z80_WITH_QYESCACHEBOOL"")set(Z80_WITH_ZILOG_NMOS_LD_A_IR_BUGYESCACHEBOOL"")add_subdirectory(dependencies/Z80)target_link_libraries(your-target Z80)

It is important to set theZ80_SHARED_LIBS option. Otherwise, CMake will build the library type indicated byBUILD_SHARED_LIBS, which may not be the desired one.

The source code of the emulator can be configured at compile time by predefining a series of macros. BothZ80.h andZ80.c obey the first two explained below. The rest of the macros are only relevant when compilingZ80.c:

• #define Z80_EXTERNAL_HEADER "header-name.h"
  Specifies the only external header to#include, replacing all others.
  Predefine this macro to provide a header file that defines the external types and macros used by the emulator, thus preventing your project from depending onZeta. You can use this when compilingZ80.c within your project or (if your types do not break the binary compatibility) when including<Z80.h> and linking against a pre-built Z80 library.

• #define Z80_STATIC
  Indicates that the emulator is a static library.
  This macro must be predefined when buildingZ80.c as a static library. Additionally, if you compileZ80.c directly within your project or link your program against the static version of the Z80 library, ensure that this macro is defined before including"Z80.h" or<Z80.h>.

• #define Z80_WITH_LOCAL_HEADER
  TellsZ80.c to#include "Z80.h" instead of<Z80.h>.

The optional features of the emulator mentioned in the "Configure" section of "Installation from source code" are disabled by default. If you compileZ80.c within your project, enable those features you need by predefining their respective activation macros. They have the same name as theirCMake equivalents:

• #defineZ80_WITH_EXECUTE
• #defineZ80_WITH_FULL_IM0
• #defineZ80_WITH_IM0_RETX_NOTIFICATIONS
• #defineZ80_WITH_PARITY_COMPUTATION
• #defineZ80_WITH_PRECOMPUTED_DAA
• #defineZ80_WITH_Q
• #defineZ80_WITH_SPECIAL_RESET
• #defineZ80_WITH_UNOFFICIAL_RETI
• #defineZ80_WITH_ZILOG_NMOS_LD_A_IR_BUG

Except forZ80_EXTERNAL_HEADER, the above macros can be empty; the source code only checks whether they are defined.

This emulator has been used by the following projects (listed in alphabetical order):

• Augmentinel_{bySimon Owen} ⟩GitHub
• ceda-cemu_{byRetrofficina GLG Programs} ⟩GitHub
• CPM-Emulator_{byMarc Sibert} ⟩GitHub
• f80_{byRichard J. Prinz} ⟩GitHub
• Google Capture the Flag (2021)_byGoogle ⟩GitHub
• King of the Grid_{byAlex Siryi} ⟩GitHub
• MSX1 Emulator for Raspberry Pi Pico_{byshippoiincho} ⟩GitHub
• MZ-1500 Emulator for Raspberry Pi Pico_{byshippoiincho} ⟩GitHub
• MZ-2000/80B Emulator for Raspberry Pi Pico_{byshippoiincho} ⟩GitHub
• PASOPIA Emulator for Raspberry Pi Pico_{byshippoiincho} ⟩GitHub
• PC-6001mkII Emulator for Raspberry Pi Pico_{byshippoiincho} ⟩GitHub
• pico-sorcerer-2_byfruit-bat ⟩GitHub
• pico-zxspectrum_byfruit-bat ⟩GitHub
• RadZ80_byRadAd ⟩GitHub
• SEGA SC-3000 Emulator for Raspberry Pi Pico_{byshippoiincho} ⟩GitHub
• tihle_{byPeter Marheine} ⟩GitHub ·GitLab
• TileMap_{bySimon Owen} ⟩GitHub
• tranZPUter^FusionX_{byPhilip Smart} ⟩GitHub
• Zemu_{byJay Valentine} ⟩GitHub ·RubyGems

Many thanks to the following individuals (in alphabetical order):

• Akimov, Vadim (lvd)
  • For testing the library on many different platforms and CPU architectures.
• azesmbog^🏆
  1. For validating tests on real hardware.^1.1
  2. For discovering the unstable behavior of theccf/scf instructions.
  3. For testing theccf/scf instructions on real hardware.^2,3
  4. For his invaluable help.
• Banks, David (hoglet)^🏆
  1. For deciphering the additional flag changes of the block instructions.^4.1,4.2,5
  2. For his research on theccf/scf instructions.^5,6
• Beliansky, Anatoly (Tolik_Trek)
  • For validating tests on real hardware.^1.2
• Bobrowski, Jan
  • For fixing the"Z80 Full Instruction Set Exerciser for Spectrum".⁷
• boo_boo^🏆
  • For deciphering the behavior of MEMPTR.^8,9,10,11
• Brady, Stuart
  • For his research on theccf/scf instructions.¹²
• Brewer, Tony^🏆
  1. For his research on the special RESET.^4.3,13
  2. For helping to decipher the additional flag changes of the block instructions.⁴
  3. For conducting low-level tests on real hardware.⁴
  4. For helping me to test different undocumented behaviors of the Zilog Z80.
• Bystrov, Dmitry (Alone Coder)
  • For validating tests on real hardware.^1.2
• Chandler, Richard
  1. For his corrections to the documentation.
  2. For validating tests on real hardware.¹⁴
• Chunin, Roman (CHRV)
  • For testing the behavior of MEMPTR on real hardware.^8,9,10,11
• Conway, Simon (BadBeard)
  • For validating the"Z80 Test Suite" on several Z80 clones.¹⁵
• Cooke, Simon^🏆
  • For discovering how theout (c),0 instruction behaves on the Zilog Z80 CMOS.¹⁶
• Cringle, Frank D.
  • For writing the"Z80 Instruction Set Exerciser".¹⁷
• Devic, Goran
  • For his research on undocumented behaviors of the Z80 CPU.¹⁸
• Dunn, Paul (ZXDunny)
  • For his corrections to the documentation.
• Equinox
  • For his corrections to the documentation.
• Flammenkamp, Achim
  • For his article on Z80 interrupts.¹⁹
• Gimeno Fortea, Pedro^🏆
  1. For his research work.²⁰
  2. For writing the first-ever ZX Spectrum emulator.^21,22
• goodboy
  • For testing the behavior of MEMPTR on real hardware.^8,9,10,11
• Greenway, Ian
  • For testing theccf/scf instructions on real hardware.^12,23
• Harston, Jonathan Graham
  1. For his research work.
  2. For his technical documents about the Zilog Z80.^24,25,26
  3. For porting the"Z80 Instruction Set Exerciser" to the ZX Spectrum.²⁷
• Helcmanovsky, Peter (Ped7g)^🎖️
  1. For helping me to write the"IN-MEMPTR" test.
  2. For writing the"Z80 Block Flags Test".^1,28
  3. For writing the"Z80 CCF SCF Outcome Stability" test.²⁸
  4. For writing the"Z80 INT Skip" test.²⁸
  5. For his research on the unstable behavior of theccf/scf instructions.
  6. For his invaluable help.
• Iborra Debón, Víctor (Eremus)
  • For validating tests on real hardware.
• icebear
  • For testing the behavior of MEMPTR on real hardware.^8,9,10,11
• ICEknight
  • For validating tests on real hardware.
• Kladov, Vladimir^🏆
  • For deciphering the behavior of MEMPTR.^8,9,10,11
• Krook, Magnus
  • For validating tests on real hardware.^1.3
• London, Matthew (mattinx)
  • For validating tests on real hardware.
• Martínez Cantero, Ricardo (Kyp)
  • For validating tests on real hardware.
• Molodtsov, Aleksandr
  • For testing the behavior of MEMPTR on real hardware.^8,9,10,11
• Nair, Arjun
  • For validating tests on real hardware.¹
• Nicolás-González, César
  • For helping me to investigate the unstable behavior of theccf/scf instructions.
• Ortega Sosa, Sofía
  1. For optimizing the emulator.
  2. For her support.
• Owen, Simon
  • For the idea of the hooking method used in this emulator.
• Ownby, Matthew P.
  • For his research on the state of the registers after POWER-ON.²⁹
• Rak, Patrik^🏆
  1. For improving the"Z80 Instruction Set Exerciser for Spectrum".³⁰
  2. For deciphering the behavior of theccf/scf instructions.^15,30
  3. For writing the"Zilog Z80 CPU Test Suite".^30,31
  4. For his research on the unstable behavior of theccf/scf instructions.
• Rodríguez Jódar, Miguel Ángel (mcleod_ideafix)
  • For his research on the state of the registers after POWER-ON/RESET.³²
• Rodríguez Palomino, Mario (r-lyeh)
  • For teaching me how emulators work.
• Sainz de Baranda y Romero, Manuel
  • For teaching me programming and giving me my first computer.
• Sánchez Ordiñana, José Ismael (Vaporatorius)
  • For validating tests on real hardware.^31.1,33
• Sevillano Mancilla, Marta (TheMartian)
  • For validating tests on real hardware.^14.1
• Stevenson, Dave
  1. For testing the special RESET on real hardware.¹³
  2. For conducting low-level tests on real hardware.^4.4
• Titov, Andrey (Titus)
  • For his research on theccf/scf instructions.^2,3
• Vučenović, Zoran
  • For writing thePascal binding.
• Weissflog, Andre (Floh)^🏆
  1. For discovering that thereti/retn instructions defer the acceptance of the maskable interrupt.³⁴
  2. For writing the"Visual Z80 Remix" simulator.³⁵
• Wilkinson, Oli (evolutional)
  • For validating tests on real hardware.¹
• Wlodek
  • For testing the behavior of MEMPTR on real hardware.^8,9,10,11
• Woodmass, Mark (Woody)^🎖️
  1. For his invaluable contributions to the emuscene.
  2. For writing the"Z80 Test Suite".¹⁵
  3. For his research on theccf/scf instructions.³⁶
  4. For writing the"HALT2INT" test.
  5. For writing the"EIHALT" test.
• Young, Sean^🏆
  1. For his research work.
  2. For his technical documents about the Zilog Z80.^20,29,37
• ZXGuesser
  • For validating tests on real hardware.

1. https://spectrumcomputing.co.uk/forums/viewtopic.php?t=6102
   1. https://spectrumcomputing.co.uk/forums/viewtopic.php?p=83384#p83384
   2. https://spectrumcomputing.co.uk/forums/viewtopic.php?p=83041#p83041
   3. https://spectrumcomputing.co.uk/forums/viewtopic.php?p=83157#p83157
2. https://zx-pk.ru/threads/34173-revers-inzhiniring-z80.html
3. https://zx-pk.ru/threads/35936-zagadka-plavayushchikh-flagov-scf-ccf-raskryta!.html
4. https://stardot.org.uk/forums/viewtopic.php?t=15464
   1. https://stardot.org.uk/forums/viewtopic.php?p=211042#p211042
   2. https://stardot.org.uk/forums/viewtopic.php?p=212021#p212021
   3. https://stardot.org.uk/forums/viewtopic.php?p=357136#p357136
   4. https://stardot.org.uk/forums/viewtopic.php?p=212360#p212360
5. Banks, David (2018-08-21)."Undocumented Z80 Flags" rev. 1.0.
   • https://stardot.org.uk/forums/download/file.php?id=39831
   • https://github.com/hoglet67/Z80Decoder/wiki/Undocumented-Flags
6. https://github.com/hoglet67/Z80Decoder/wiki/Unstable-CCF-SCF-Behaviour
7. http://wizard.ae.krakow.pl/~jb/qaop/tests.html
8. https://zxpress.ru/zxnet/zxnet.pc/5909
9. https://zx-pk.ru/threads/2506-komanda-bit-n-(hl).html
10. https://zx-pk.ru/threads/2586-prosba-realshchikam-ot-emulyatorshchikov.html
11. boo_boo; Kladov, Vladimir (2006-03-29)."MEMPTR, Esoteric Register of the Zilog Z80 CPU".
    • https://zx-pk.ru/showpost.php?p=43688
    • https://zx-pk.ru/attachment.php?attachmentid=2984
    • https://zx-pk.ru/showpost.php?p=43800
    • https://zx-pk.ru/attachment.php?attachmentid=2989
12. https://sourceforge.net/p/fuse-emulator/mailman/message/6929573
13. Brewer, Tony (2014-12)."Z80 Special Reset".
    • http://primrosebank.net/computers/z80/z80_special_reset.htm
14. https://spectrumcomputing.co.uk/forums/viewtopic.php?t=10555
    1. https://spectrumcomputing.co.uk/forums/viewtopic.php?p=132144#p132144
15. https://worldofspectrum.org/forums/discussion/20345
16. https://groups.google.com/g/comp.os.cpm/c/HfSTFpaIkuU/m/KotvMWu3bZoJ
17. Cringle, Frank D. (1998-01-28)."Yaze - Yet Another Z80 Emulator" v1.10.
    • ftp://ftp.ping.de/pub/misc/emulators/yaze-1.10.tar.gz
18. https://baltazarstudios.com/zilog-z80-undocumented-behavior
19. Flammenkamp, Achim."Interrupt Behaviour of the Z80 CPU".
    • http://z80.info/interrup.htm
20. Young, Sean (1998-10)."Z80 Undocumented Features (in Software Behaviour)" v0.3.
    • http://www.msxnet.org/tech/Z80/z80undoc.txt
21. https://elmundodelspectrum.com/desenterrando-el-primer-emulador-de-spectrum
22. https://elmundodelspectrum.com/con-vosotros-el-emulador-de-pedro-gimeno-1989
23. https://sourceforge.net/p/fuse-emulator/mailman/message/4502844
24. Harston, Jonathan Graham (2008)."Full Z80 Opcode List Including Undocumented Opcodes" v0.11 (revised).
    • https://mdfs.net/Docs/Comp/Z80/OpList
25. Harston, Jonathan Graham (2012)."Z80 Microprocessor Undocumented Instructions" v0.15.
    • https://mdfs.net/Docs/Comp/Z80/UnDocOps
26. Harston, Jonathan Graham (2014)."Z80 Opcode Map" v0.10 (revised).
    • https://mdfs.net/Docs/Comp/Z80/OpCodeMap
27. https://mdfs.net/Software/Z80/Exerciser/Spectrum
28. https://github.com/MrKWatkins/ZXSpectrumNextTests
29. Young, Sean (2005-09-18)."Undocumented Z80 Documented, The" v0.91.
    • http://www.myquest.nl/z80undocumented
    • http://www.myquest.nl/z80undocumented/z80-documented-v0.91.pdf
30. https://worldofspectrum.org/forums/discussion/41704
    • http://zxds.raxoft.cz/taps/misc/zexall2.zip
31. https://worldofspectrum.org/forums/discussion/41834
    • http://zxds.raxoft.cz/taps/misc/z80test-1.0.zip
    • https://github.com/raxoft/z80test
    1. https://worldofspectrum.org/forums/discussion/comment/668760/#Comment_668760
32. https://worldofspectrum.org/forums/discussion/34574
33. https://jisanchez.com/test-a-dos-placas-de-zx-spectrum
34. Weissflog, Andre (2021-12-17)."New Cycle-Stepped Z80 Emulator, A".
    • https://floooh.github.io/2021/12/17/cycle-stepped-z80.html
35. https://github.com/floooh/v6502r
36. https://groups.google.com/g/comp.sys.sinclair/c/WPsPr6j6w5k/m/O_u1zNQf3VYJ
37. Young, Sean (1997-09-21)."Zilog Z80 CPU Specifications".
    • http://www.msxnet.org/tech/Z80/z80.zip

Copyright © 1999-2025 Manuel Sainz de Baranda y Goñi.

This library isfree software: you can redistribute it and/or modify it under the terms of theGNU Lesser General Public License as published by theFree Software Foundation, either version 3 of the License, or (at your option) any later version.

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