Please support Z80 Assembler (ZX81, ZX Spectrum etc)

You can add custom syntax definitions to Textastic by using TextMate bundles or Sublime Text packages. See
https://www.textasticapp.com/v9/manual/customization/custom_syntax_themes_templates.html

A search for "Z80 Assembly Sublime Text" brought up this Sublime Text package which should work:

https://github.com/mrcook/Z80Assembly

Just put the file "Z80Assembly.tmLanguage.sublime-syntax" into the folder "Local Files/#Textastic/Z80/" and reload customizations. Then you should be able to select "Z80 Assembly" as a syntax definition in the file properties.

Here's how to get the file on an iPad:

• Go to https://github.com/mrcook/Z80Assembly in Safari.
• Tap the green "Code" button and select "Download ZIP".
• Unzip the file in the Files app.
• Copy the file "Z80Assembly.tmLanguage.sublime-syntax" to "On my iPad/Textastic/#Textastic/Z80/".