ZX812.0.10 - App Store

Welcome to a taste of early 1980s home computing.

This app focuses on the Sinclair ZX81 experience and is loaded with example software. A streamlined watchOS app is included, offering saved session syncing with the iOS app on the paired iPhone.

Background:

In 1980 the British company Science of Cambridge (later renamed Sinclair Research) released the Sinclair ZX80 home computer. The computer was developed with another technology company, Nine Tiles, and manufactured in a Timex Corporation factory in Dundee, Scotland. Followed in March 1981 by the even more popular successor, the Sinclair ZX81, both models had a profound impact on home and hobbyist computing in the UK and many other countries. Timex Corporation and Sinclair Research continued their joint venture and released the Timex Sinclair 1000 (TS1000) and 1500 (TS1500) variants of the ZX81 for the US market in July 1982 and July 1983 respectively.

Meanwhile, another iconic British home computer, the Sinclair ZX Spectrum, was under development and hit the market in April 1982... but that's another story.
Special thanks to Nine Tiles for granting permission to include the ROM code, to which they retain the intellectual property rights after all these years.

Additionally, many thanks to all the developers of the loaded ZX81 software who have all granted permission to include their titles in the app. We hope this list of software will continue to grow in future updates.

Version History Corrected a bug introduced by the previous version that prevented the virtual gamepad buttons working correctly. 2.0.10 Sep 12 iOS/iPadOS app:
• Fixes some of the sound settings not being retained after applying.
• Improves the virtual joystick functionality and adds support for connecting popular game controllers.

watchOS app:
• Adds virtual ZXpand joystick support.
• Adds AY and MIC / VSYNC sound. 2.0.9 Sep 11 Apple Watch app:
• Reduced Apple Watch CPU usage by over 30% compared with the previous version.
• Added a press-and-hold magnifier for the CRT display. Press and hold anywhere on the display, then move your finger to pan. 2.0.8 Aug 19 • Minor improvements to the text displayed in the app.
• Added a watch app for devices running watchOS 26. 2.0.7 Aug 11 Various fixes for devices running versions of iOS and iPadOS earlier than 26. 2.0.6 Aug 5 Fixed a bug with Chroma support introduced in the previous app update. 2.0.5 Jul 27 • Optimized the sound and CRT emulation to further reduce CPU usage on the host device.
• Improved the accuracy of Z80 Interrupt Mode 0 and Chroma mode emulation.
• Added User Defined Graphics (UDG) management, allowing custom characters to be captured, imported, exported, edited and applied to the simulated RAM.
• Added new settings for selecting imported custom ROMs. 2.0.4 Jul 26 • Added the Binary Logic ZX81 (BL81) ROM by Geoff Wearmouth, along with the Peeker5 program to demonstrate improved floating-point accuracy of the ROM.
• Further emulation optimizations dramatically reduce CPU usage on the host device.
• Added a new Caps Lock mode that automatically turns off after a single key press. 2.0.3 Jul 16 • Significant emulation optimisations, which reduce the CPU load by about 60%.
• Added a new Video Color Inversion option.
• Minor layout improvement when running the iPad app on macOS. 2.0.2 Jul 5 • Improved support for running the iPad app on macOS.
• Added support for managing POKEs when loading programs (tap the simulated screen to access the new option). 2.0.1 Jun 28 This is update is a large internal refactor to modernize the app codebase and improve the program loading functionality. Other changes include:
• improvements to the sound generation.
• import option for snapshots from the EightOne app.
• fix when loading programs saved in FAST mode (thank you Simon Goodwin for reporting the problem).
• added games by David Spinet & Don Crawford: Robotack 2024 & Zoust. 2.0.0 Jun 22 Enables ZX81/ZX80 program file loading (iOS/iPadOS 14+). 1.13.5 04/06/2024 This update resolves crashes when:
• opening the app on devices with iOS 12
• exporting a snapshot saved with the 48K RAM setting 1.13.4 04/02/2024 • Refinements to the simulated computer fonts option in the app user interface: adds a ZX80 option, now supports all ZX81 characters, reimagined characters to support other languages, and using the fonts in the memory dump viewer.
• Updated Sebastien Andrivet’s Factory game.
• Dr Beep’s USCII utility and LUNAPARK81 game.
• 3D Star Raid game by Bukster Games.
• Paul Daniels' games: QFrogger, QDepthCharge. 1.13.3 11/27/2023 Bug fix when switching between simulated computers with different logos or keyboard styling. 1.13.2 05/27/2023 • iPadOS Multi-window support added for the Z80 debugger (tap on the emulated screen to reveal the debugger option).
• Export option from the saved slots to create .z81 snapshot files for the EightyOne emulator.
• Updated tape player functionality to avoid a fade in transition - special thanks to Stéphane Blanchonnet for reporting the problem and testing the fix.
• The latest programs from Johan Koelman: 10=, Bouncing Dots, TRICDEL, YAHTK, Cubic Maze.
• Dungeons of Zedd game by Walter Ariel Risi.
• Escape from Tokat Dungeon game by Salvatore Andamio.
• BattleZXone game by Bukster Games.
• Krystal graphics demo by Nickmann László.
• Rock Crush II: The Power Of Dan (2022) game by Steven McDonald. 1.13.0 05/15/2023 • More stability fixes
• RetroSnake game by Camilo Eid Jordán 1.12.2 09/18/2022 • Corrected:
- multiple crash scenarios.
- physical keyboard support and screenshot saving for macOS (can be installed on Apple Silicon Macs with an iPadOS interface layout).
- mapping of physical quote key when the ZX80 ROM is selected.
Special thanks to Allan McLeod for reporting problems and testing changes.
• Super Shogun game by Dr Beep.
• All of Simon Fawkes' games: Death Trap, Dodge It, Fun Fair Adventure, Pengy, Tablets of Hippocrates, Trojan Dragon. 1.12.1 07/31/2022 • Improved accuracy of inserted Z80 CPU wait states. Now scores 100% based on Dr Carlo Delhez’s Clock Frequency (CLCKFREQ) test program. Many thanks to Paul Farrow for his persistence and support in helping to reach this level of accuracy.
• VSYNC 3 channel sound demo using a Tim Follin’s tune from a type-in magazine program listing. Ported by Kelly Murta.
• Games by Walter Ariel Risi: Cursed Catacombs, Zeddytron 2081.
• Latest game from Bukster Games: Valley of the Kings. 1.12.0 07/03/2022 • Japanese translation by Shigeru Kumokoshi
• Option to jump to specific addresses in the debugger memory dump view (suggested by Jacob Krall)
• Moskão Fighter game by Kelly Murta
• Updated version of Against the Elements game by Paul Farrow 1.11.2 03/29/2022 • Fixed the lists styling in the Z80 debugger views for iOS/iPadOS 15
• Editing functionality for the bytes displayed in the Memory Dump debugger view
• Roger Dymond’s games: Beetle, Fox and Geese, Ludo, Noughts and Crosses, Snakes and Ladders
• Dr Beep’s games: Reaction, Slingshot Sam, Kayak, Sir Clive 1.11.1 01/02/2022 • New functionality to convert P files to tape audio for real ZX81 computers
• Tweaks for OS & iPadOS 15
• Bitnamic Software’s 2019 deluxe version of Em Busca dos Tesouros (Treasure Quest)
• John Newcombe’s ZX Reactor simulator
• Dr Beep's Apple Pie game 1.11.0 09/20/2021 Fixes the Software list, which showed the incorrect computer types required for each program. 1.10.6 06/12/2021 • Added 2003 Shoulders of Giants ROM by Geoff Wearmouth including its disassembly symbols in the Z80 debugger.
• Improved hardware keyboard support for iOS/iPadOS 13.4 and above: i) Arrow and other keys supported as suggested by Mikael Bonnier, ii) Maintained keypresses supported.
• Fixed bug when displaying the LD (IX+d), n and LD (IY+d), n instructions in the Z80 debugger. Special thanks to Steven McDonald for reporting the problem.
• Fixed bug where the app setting for the interface color style was ignored.
• Zonkey Kong game by David Spinnett and Don Crawford. 1.10.5 06/12/2021 • Fixed problem with Chroma 81 address logic. Thanks to Paul Farrow and Steven McDonald identifying the problem.
• Two new ZX81 ROM options:
i) 622 variant identified by Lardo Boffin, Mark (AKA 1024MAK) and Moggy
ii) Big Bang x2c / Shoulders of Giants started by Geoff Wearmouth and progressed by Ludwig Röck and Zsolt Gaál
• Z-XTRICATOR game updated to the single file loader by Paul Farrow.
• Hungarian translation by Sáfár Sándor. 1.10.4 05/02/2021