# add this to your monitor definition file if you don't already have a similar mode

# 640 x 400     (37.5 kHz, 89 Hz)
startmode
 mode_name:640 x 400
 x_res:640
 y_res:400
 pixel_rate:31500
 h_timings:62,64,30,640,30,14
 v_timings:3,16,0,400,0,1
 sync_pol:3
endmode
