ML690/ML691 User’s Guide  96
Appendix C: 
Specications
Note: Specications are subject to change without 
notice.
Print Method
Impact dot matrix
Printhead
24 pins, 0.2 mm (0.008”) diameter, with thermal 
protection
Interfaces
Standard:    Bi-directional parallel, IEEE-1284  
  compliant, USB 2.0
Optional:   RS-232C Serial
Receive Buffer Size
Maximum 128K   
Printhead Life
400 million characters average in 10 cpi draft 
mode at 25% duty and 35% page density
Reliability
Ribbon Life
ML690: approx. 8 million characters (Draft Mode)
ML691: approx. 13 million characters (Draft Mode)
Emulations (co-resident)
IBM Proprinter
Epson FX
Physical Specications
Note: Height dimensions do not include the acoustic 
cover.
ML690
  Size (WxDxH):   16.3 x 12.6 x 6.26” 
        (414 x 320 x 159 mm)
  Weight:    16.4 lb. (7.5 kg)
ML691
  Size (WxDxH):  22.36 x 12.6 x 6.26” 
        (568 x 320 x 159 mm)
  Weight:    22 lb. (10 kg)