* #1C00 and #1F00 are bad decodings/mirrors of [[CRTC]] ports #BC00 and #BF00
* These ports will clash with other hardware (but do work more or less)
* A15=0 doesntdoesn't trigger the [[Gate Array]] (which would also require A14=1)
* A13=0 does trigger [[Upper ROM Bank Number]] (but the IN's don't cause problems since the ROM bank is write-only, the OUT's do activate bank 16 and 17, but usually don't cause problems since these banks usually contain mirrors of the BASIC ROM)