The  program  CHRS.COM sends a command string to  the  printer.  
The  command  string  is  entered on the  CP/M  command  line  as 
follows:  chrs 0f                  ==>compressed on
          chrs 1b 34               ==>italics on
          chrs 1b 2d 01            ==>underline on
          chrs 1b 40               ==>codes off/reset TOF
          chrs 1b 47               ==>double strike on
          chrs 1b 45               ==>emphasized on
          chrs 1b 57 01            ==>double width on
          chrs 1b 43 #lines        ==>form length by # lines
          chrs 1b 43 00 #inches    ==>form length by # inches
          chrs 1b 55 01            ==>unidirectional on
          chrs 1b 4e #lines(opt.)  ==>SOP # lines (13 default)
          chrs 1b 38               ==>disable paper out sensor
          chrs 1b 30               ==>sets 1/8" line spacing

NOTE:   The  above  examples  are supposed to be  good  for  most 
printers that emulate the Epson control commands and they work on 
my  Epson MX-100 with Graftrax Plus.   Letters may be entered  on 
the command line in either upper- or lowercase.
REMEMBER:  You're sending HEX commands to the printer.  If you're
telling it that the form length is 51 lines (8 1/2"), the proper
hex code is 33, not 51 (51 would tell the printer that your form
is 81 lines, or 13 1/2", long).  Hex commands are the same as 
decimal commands thru 9; after 9, they go their separate ways.