Re: Back & Forth - 4tH I/O and You

On 18/05/2025 1:02 am, Hans Bezemer wrote:

Back & Forth - 4tH I/O and You
 
How is 4tH, a Forth compiler, able to define an entire I/O system with so few words? And still capable of supporting most of the ANS FILE word set? Well, the idea isn't new - and was inspired by an unexpected computer.
 
 
https://youtu.be/4G_15r01bmc

Many forths have (or had) a mechanism for redirecting console output.
Usually this was redirection to a printer as most OS had a dedicated
character-oriented channel for the latter.  OTOH this redirection
isn't something I've used.  Only one application springs to mind and
even then it felt out of the norm:

\ Set EMIT to OFILE
: DISK ( -- )
  ['] writech [ sys-vec 4 + ] literal ! ;

For me it's redirection that feels C-like and the ANS file wordset
a blessing relative to the native FCB file mechanism of CP/M (as
clever and memory-efficient as the latter was).

As always, another thought-provoking video.  Thanks, Hans.