Available options: (read/write DCO, read DCS)
0001 RX: 32-bit register display
0002 TM: trace into interrupts
0004 allow dumping of CP-dependent characters
0008 always assume InDOS flag non-zero, to debug DOS or TSRs
0010 disallow paged output to StdOut
0040 display raw hexadecimal content of FPU registers
0100 when prompting during paging, do not use DOS for input
0200 do not execute HLT instruction to idle
0400 do not idle, the keyboard BIOS idles itself
0800 use getinput function for int 21h interactive input
1000 in disp_*_size use SI units (kB = 1000, etc). overrides 2000!
2000 in disp_*_size use JEDEC units (KB = 1024)
4000 enable serial I/O (port 02F8h interrupt 0Bh)
8000 disable serial I/O when breaking after Ctrl pressed for a while
0001_0000 gg: do not skip a breakpoint (bb or gg)
0002_0000 gg: do not auto-repeat
0004_0000 T/TP/P: do not skip a (bb) breakpoint
0008_0000 gg: do not auto-repeat after bb hit
0010_0000 T/TP/P: do not auto-repeat after bb hit
0020_0000 gg: do not auto-repeat after unexpectedinterrupt
0040_0000 T/TP/P: do not auto-repeat after unexpectedinterrupt
0080_0000 S: do not dump data after matches
1000_0000 R: do not repeat disassembly
2000_0000 R: do not show memory reference in disassembly
4000_0000 quiet command line buffer input
8000_0000 quiet command line buffer output
