Good article from Your Spectrum magazine (1984) regarding methods of extending ZX Spectrum BASIC.[googleapps domain="drive" dir="file/d/0B3YJXuFJXqAYLWZzeEQ5TTNsX1U/preview" query="" width="640" height="480" /]
ECMAScript 6 new features:http://es6-features.org/#ConstantsECMAScript 7 new deatures:https://h3manth.com/new/blog/2015/es7-features/
Purchased Interface 1 bis for the ZX Spectrum. There are plenty information about it and installing and preparing SD card on manufacturers site https://sites.google.com/site/interface1bis/ But I have encountered a problem - could not start it and was allways getting "file not found" error.Did all steps described in troubleshooting video https://www.youtube.com/watch?v=QYHhWQyVWAU Loaded OpSys from PC using LOAD command, program loads OK. But when I do NEW and then RUN I get "file not found" error. Solution I found was that I had to repeat all prepare SD card steps, but additionally had to add comparability with Windows 8 (and run as administrator off course) option (I was running Windows 10) to LDCSetup.exe and later to the 'Prepare new card' utility.So, In short - add Windows 8 compatibility to Interface 1 bis utilities.
Making games in ZX Spectrum assembly book ( russian lang.):http://zxpress.ru/book.php?id=2How to write ZX Spectrum games tutorial in English:https://chuntey.wordpress.com/2012/12/18/how-to-write-zx-spectrum-games-chapter-1/Spectrum ROM routines:http://skoolkit.ca/disassemblies/rom/asm/2852.htmlZ80 instruction set:http://clrhome.org/table/Group in FB dedicated for Z80 assembly programming:https://www.facebook.com/groups/z80asm/WOS forum link:http://www.worldofspectrum.org/forums/categories/assemblerAnother forum (ru):http://zx-pk.ru/forums/14-programmirovanie.htmlSome more books (ru):http://vtrdos.ru/