SYS-functions.txt: Elaborate on D in SYS D
SYS-functions.txt: Elaborate on D in SYS D

kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom