I have run arm forths on the   
       Raspberry 1 : 32 bits   
       Orange pi one plus : 64 bits   
       Orangepi 800 : 64 bit   
      
   You can have fun only if you control the hardware for   
   those single board computers.   
   For the Orangepi 800 I have full schematics (20 page pdf)   
   and the description of the soc (RK3399). (1000 page pdf).   
   (Same for OPI 1+).   
      
   I have defined a common interface.   
   Numbering the gpio pins: system dependant.   
      
   A word MMAP-IO that assumes the variable   
   PERIPHERALS is containing the hardware address.   
   If you have root privilege MMAP-IO fills   
   VMA-IO with the virtual address.   
   Now can you access all hardware in as far you can   
   distill information from the soc description.   
      
   The API I decided upon is   
   (function gpio -- )   
   Make gpio perform the function.   
   -2 (input ) and -1 (output) are fixed.   
   Other function value are implementation defined.   
      
   gpio-on gpio-off ( gpio -- )   
   turn the pin on and off.   
   gpio-in (gpio -- bit) deliver a cell with one bit up.   
      
   You can get reasonably far with this.   
   The orange pi 800 (similar to the raspberry pi 400)   
   has a r.pi 1 connector. I connected a lcd1602   
   (16 by 2 character display) to the orange pi one plus.   
   The same software can be used, merely by configuring   
   the gpio numbers .   
      
   In ciforth WANT fashion the library contains the software   
   for the 3 boards, governed by properly defining   
   ?RP1 ?OP1 ?OP2 .   
      
   (I have reported on MMAP-IO before. It went from   
   c-with-resident-lib to c-static-linked to   
   >1-megabyte-assembler to 10-line-assembler to   
   6-line-high-level-forth ).   
      
   In the NeShan board RICV I managed to configure   
   the serial port to midi 31.25 baudrate, impossible   
   to do under linux with the facilities provided.   
   --   
   Don't praise the day before the evening. One swallow doesn't make spring.   
   You must not say "hey" before you have crossed the bridge. Don't sell the   
   hide of the bear until you shot it. Better one bird in the hand than ten in   
   the air. First gain is a cat purring.            - the Wise from Antrim -   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)