LED test - PC-G815 https://github.com/z88dk/z88dk/issues/2664

ledg815.c

/*
  zcc +g800 -create-app -bn ledg815 ledg815.c
*/

/*
gprint data
PC-G815 has 6x8 dots (Same as PC-G850)

char balloon[6] = {0x4e, 0x5f, 0x3f, 0x1d, 0x0e, 0x00};
*/

#include <stdio.h>
#include <stdlib.h>

void main()
{
  while(getk());

  outp (0x54,0xc0);
  outp (0x58,0xc0); /* y scroll reset */

  for (int y=0; y<8; y++) {
    outp (0x54,0xb8+y);
    outp (0x58,0xb8+y);
/* y position 0xb8+y (0-7 0xc0)
   0xc0-0xff changes this state!
   +---------------------------------------------+
   |b8h                   |                   bch|
   |b9h                   |                   bdh|
   |bah                   |                   beh|
   |bbh                   |                   bfh|
   +---------------------------------------------+
*/
    outp (0x54, 0x40);
    outp (0x58, 0x40);
/*
   0x54 - x position 040+x (0-59)
   60 = 10 charcters x 6 dots
   +---------------------------------------------+
   |40h ... 7bh           |           7bh ... 40h|
   |40h ... 7bh           |           7bh ... 40h|
   |40h ... 7bh           |           7bh ... 40h|
   |40h ... 7bh           |           7bh ... 40h|
   +---------------------------------------------+
   0x58 x position 040+x (0-11)
   12 = 2 charcters x 6 dots
   +---------------------------------------------+
   |           40h ... 4bh|4bh ... 40h           |
   |           40h ... 4bh|4bh ... 40h           |
   |           40h ... 4bh|4bh ... 40h           |
   |           40h ... 4bh|4bh ... 40h           |
   +---------------------------------------------+
   The right half is horizontally reversed!!
*/
    for (int x=0; x<10; x++) {
    /* 0x54 setiing to 0x56 write, 0x57 read */
       outp (0x56, 0x4e);
       outp (0x56, 0x5f);
       outp (0x56, 0x3f);
       outp (0x56, 0x1d);
       outp (0x56, 0x0e);
       outp (0x56, 0x00);
    }
    for (int x=0; x<2; x++) {
    /* 0x58 setiing to 0x5a write, 0x5b read */
       outp (0x5a, 0x4e);
       outp (0x5a, 0x5f);
       outp (0x5a, 0x3f);
       outp (0x5a, 0x1d);
       outp (0x5a, 0x0e);
       outp (0x5a, 0x00);
    }
  }

  while(!getk());
}
/*
scroll (0-63, line*8?)
outp (0x56, 0xc0+y);
outp (0x5a, 0xc0+y);

busy check
while (inp(0x55) & 0x80);
while (inp(0x59) & 0x80);

read
d = inp(0x57):
d = inp(0x5b):
*/