Volex TTX2000 S Issue 1.2: Routine at 0F11

0F11: write_top_sixels: Write bitmap in D to three rows of font data.

Used by the routine at generate_mosaics.
write_top_sixels	0F11	LD (HL),D
	0F12	INC HL
	0F13	LD (HL),D
	0F14	INC HL
	0F15	LD (HL),D
	0F16	INC HL
	0F17	RET