Forty-one years after I wrote my first version of this (in Z80 machine code for the ZX80/ZX81) here’s the latest, in Forth (Riscyforth for a RISC-V SBC).

This is hot off the editor, so can no doubt be optimised, but I am pretty pleased with it.

```
\ Conway's Game of Life in Forth (Riscyforth)
\ Copyright (c) Adrian McMenamin, 2022
\ Loosely inspired by the NCURSES How-To version
\ You may distribute this code or a modified version subject
\ to the terms of the GNU GPL, either version 2 or any later
\ version at your discretion
\ See https://github.com/mcmenaminadrian/riscyforth for latest code
loadmodule ./modules/ncurses/ncurses.so
0 constant startx
0 constant starty
120 constant endx
50 constant endy
variable grida
variable gridb
variable countup
variable scale
endx endy * scale !
: memsetup
scale @ allocate 0<> IF ." ALLOCATE failed" exit then grida !
scale @ allocate 0<> IF ." ALLOCATE failed" exit then gridb !
scale @ 0 do 0 i grida @ + C! 0 i gridb @ + C! loop
;
: memclean
grida @ free
gridb @ free
;
variable aheadx
variable behindx
variable aheady
variable behindy
variable currentpos
: updategrid
\ swap the numbers about
@ swap @
grida ! gridb !
endy starty do
i 1+ endy mod aheady !
i 1- endy mod dup 0< if endy + then behindy !
endx startx do
0 countup !
i 1+ endx mod aheadx !
i 1- endx mod dup 0< if endx + then behindx !
\ all the aheadx
aheadx @ behindy @ endx * + gridb @ + C@ 1 = IF countup @ 1+ countup ! then
aheadx @ j endx * + gridb @ + C@ 1 = IF countup @ 1+ countup ! then
aheadx @ aheady @ endx * + gridb @ + C@ 1 = IF countup @ 1+ countup ! then
\ equal x
i behindy @ endx * + gridb @ + C@ 1 = if countup @ 1+ countup ! then
i aheady @ endx * + gridb @ + C@ 1 = if countup @ 1+ countup ! then
\ behindx
behindx @ behindy @ endx * + gridb @ + C@ 1 = IF countup @ 1+ countup ! then
behindx @ j endx * + gridb @ + C@ 1 = IF countup @ 1+ countup ! then
behindx @ aheady @ endx * + gridb @ + C@ 1 = IF countup @ 1+ countup ! then
\ now update display grid
i j endx * + dup currentpos !
gridb @ + C@ currentpos @ grida @ + C!
countup @ 3 > if 0 currentpos @ grida @ + C! then
countup @ 3 = if 1 currentpos @ grida @ + C! then
countup @ 2 < if 0 currentpos @ grida @ + C! then
loop
loop
;
: displaygrid
endy starty do
endx startx do
i j endx * + grida @ + C@
1 = If j i 55 mvaddch else j i 32 mvaddch then
loop
loop
refresh
;
: initgrid
1 19 15 endx * + grida @ + C!
1 20 15 endx * + grida @ + C!
1 21 15 endx * + grida @ + C!
1 19 16 endx * + grida @ + C!
1 19 17 endx * + grida @ + C!
1 21 16 endx * + grida @ + C!
1 21 17 endx * + grida @ + C!
1 19 18 endx * + grida @ + C!
1 39 16 endx * + grida @ + C!
1 40 16 endx * + grida @ + C!
1 41 16 endx * + grida @ + C!
1 39 17 endx * + grida @ + C!
1 39 18 endx * + grida @ + C!
1 41 17 endx * + grida @ + C!
1 41 18 endx * + grida @ + C!
1 0 0 endx * + grida @ + C!
scale @ 0 do i grida @ + C@ i gridb @ + C! loop
;
: life
memsetup
initscr
clear
raw
keypadstd
noecho
initgrid
displaygrid
begin getch 1 key_f = while grida gridb swap updategrid displaygrid repeat
memclean
endwin
;
```