About... zxsp

zxsp with all the debugger windows open

zxsp is a simulator for the Sinclair ZX Spectrum, Sinclair ZX81, Jupiter ACE and, in the near future, Timex Sinclair home computer families from the 80's of the last century for Mac OSX. Versions for classic MacOS and old versions of Mac OS X are also available from the download page.

Loading Atic Atac from Tape
 zxsp simulates the black&white models ZX80 and ZX81, the Jupiter Ace, the ZX Spectrum models with 16K and 48K ram, the Spanish clone from Inves, the +128, +2, and the +2A/+2B including the Spanish and French localised versions. If you still own one of the emulated machines and find that the simulation does not match the original, you are welcome to contact me for further improvement. Just keep the original thing ready for testing. :-)

Manic Miner – One of my favourite games
zxsp can load from and save to a built-in virtual tape recorder or a real-world cassette recorder or a real-world computer. It also can dup real-world cassette tapes to ".tap" files or vice versa.

Screenshot from the Sound Tracker scene demo
zxsp supports ".sna" and ".z80" snapshot files, ".tap", ".tzx", ".80", ".81", ".o", ".p" tape files, ".scr" and ".gif" animated screenshots, excellent sound, precise screen and border effects, joysticks, a virtual tape recorder and virtual keyboards.

Space Invades on the ZX80
zxsp comes with a debugger with register edit for the main chips, single stepper and memory disassembly. The machine can be throttled down to 1 Hz or overdrived to 20 MHz cpu clock.

Animated GIF created with zxsp
The latest versions of zxsp require Intel Macs. They are compiled for Mac OS X 10.6 (Snow Leopard), Mac OS X 10.7 (Lion), Mac OS X 10.8 (Mountain Lion) and Mac OS X 10.9 (Mavericks). Versions for classic MacOS and old versions of Mac OS X are still available from the download page.


  1. zxsp needs to be improved, there's no option to disable instant loading of regular header/data blocks.

    1. for the current tape:
      open tape recorder window: CMD-"T" and right-click for context menu
      Or change the default settings:
      in preferences CMD-","

  2. Thanks the emulator looks awesome! Will it be able to connect to the recreated zx spectrum bluetooth keyboard?

  3. Thanks for a great emulator! I just finished a full disassembly of Space Raiders, using zxsp. The graphical memory really helped to speed things up!
    My wish list would help future disassemblies:
    - decimal view in the debugger
    - export disassembly from debugger (now I used ZX Spin on a PC)
    - export of graphical elements (sprites, UDG) from memory to bmp or png, or copy to clipboard so I can paste in a Word file.

    But thanks for the great emulator already!

    1. When i work on the memory views again, i will take this into account. Currently they are a little bit broken, especially the disassembler view, and it probably won't be fixed in the next version. So i don't know whether the next version is a good choice for you. :-) But it will have rzx recording/playback. hmm, hopefully.

  4. Hi there.. I need some help, I've been trying to run this program: http://www.boriel.com/wiki/en/index.php/ZX_BASIC:Snake.Bas but when I get to line 71 I can't seem to input the DIM command, I get a question mark right after the udg declaration... Do I need to alter the command to enter it in to your emulator? Thanks!

    1. Hi Peter. The program is no ZX Spectrum Basic. maybe it's Beta Basic, a commercial add-on to the native Spectrum Basic, but i don't know. Take a look at http://www.worldofspectrum.org/sinclairbasic/

    2. Thanks Gunter, it helps to know that it's not me that can't input the commands correctly! :-)

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