#Forth on Sinclair ZX Spectrum Next

PDF reference can be found here https://github.com/mattsteeldue/vforth-next/tree/master/doc.

To learn Forth Language or for a good reference I suggest the book "Starting FORTH" - Leo Brodie (1981, Forth Inc.). PDF hopefully available here https://www.forth.com/wp-content/uploads/2018/01/Starting-FORTH.pdf The first edition is old enough to stick on 16 bit integers numbers. In this perspective, almost all Forth source described in Leo's book are available in Screens from 800 upward.

#vForth1.6 On January 2023, I published here on GitHub the latest version that represents the fastest up to now. It seems we're approaching some Golden Ratio version...

#vForth1.52

On April 27th 2020, I received my ZX Spectrum Next (Accelerated) and immediately tried to port my Forth to the Next environment.

The purpose was to make Screens / BLOCKs system available using ZxNextOS APIs and having done it in the past for ZX Microdrive and MGT Disciple floppy diskette I really thought it was worth give a try on ZxNextOs. I'm putting here the version stable enough to be published, along with any evolution and improvement.

There are a few demo, such as "term10.f" a simple terminal to talk with Raspberry Pi Zero, if any; "chomp-chomp.f" a pac-man style game with four fast ghosts.

Screens are stored in a single file inside the SD card called "!Blocks.txt", 16 MBytes long, that can hold 16.383 Screens 1 KB each. Previous MGT or Microdrive version had 512 Bytes Screens and just 1.560 or 254x7 = 1.778 Screens, respectively. In this latest implementation a Screen is 1024 Bytes, that is two 512 bytes BLOCKs, accessed using ZxNextOS APIs.

A "Full Screen Editor" facility - EDIT - let you view and edit a Screen at a time.

A "Large file EDitor" LED, that uses all RAM available, provides a way to edit any source file up to 17.500 text lines, 85 characters each row.

All 1.792K user RAM is made available through MMU7 on which any 8K-page can be fitted in à-la "EMS" way. For String storage purpose, an HEAP facility grants access to 64K of space via FAR and POINTER definitions.

A new MOUSE library has been introduced to provide a "interrupt-driven" mouse arrow-pointer to interact with your Forth application.

Then a new AY library is work-in-progress to be used along.

I implemented an ASSEMBLER vocabulary with a peculiar notation, gracefully adapted for FORTH systems, as explained in Wiki pages https://github.com/mattsteeldue/forth-next/wiki. This ASSEMBLER recognizes the new Z80N-extension op-codes.

Documentation, PDF and the Wiki in this repository are getting shape, I suggesto to pay a visit.