More options: (read/write DCO6, read DCS6)
0001 enable video screen swapping
0002 keep video screen when disabling swapping
0010 read key from interrupt 16h when swapping (V command)
0020 run breakpoint late in debugger exception
0040 run breakpoint early in debugger exception
0200 use ROM-BIOS output even when DOS available
0400 load and write .EXE and .COM files like flat .BIN files (/F+)
0800 for loading flat .BIN files set up Stack Segment != PSP (/E+)
1000 enable 40-column friendly mode
2000 in 40-column mode indent odd D lines more
4000 in 40-column mode display dashes at half of D length
01_0000 allow to share serial IRQ handler
40_0000 run breakpoint early in putrunint
0100_0000 use ROM-BIOS I/O even when DOS available (disables script file read)
2000_0000 display flags in style 2 for R command register dump
4000_0000 display flags in style 3 for R command register dump
8000_0000 linebreak before R register dump if not column 0 (int 10h only)
