● Mode status register

Plot trigger mode upper: PTM1, bit 8

Even / odd coordinate selection bit: EOS, bit 7

Double dense interlace enable bit: DIE, bit 6

Double dense interlace drawing line: DIL, bit 5

Frame buffer switching mode bit: FCM, bit 4

V blank erase write enable bit: VBE, bit 3

TV mode selection bits: TVM, bits 2-0