Looking at the compile log, this one must be fixed for 64bit :
/home/arosdev/sources/icaros/viewer/./viewer.c:444:25: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
444 | PDTA_BitMapHeader, (ULONG)&bmh,
| ^
/home/arosdev/sources/icaros/viewer/./viewer.c: In function 'readpic_by_datatype_alpha':
/home/arosdev/sources/icaros/viewer/./viewer.c:497:25: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
497 | PDTA_BitMapHeader, (ULONG)&bmh,
| ^
(ULONG) shall be replaced by (IPTR) otherwise you cast a 64bit adress to 32bit integer
/Yannick