From Peter Moore at Barcode Index:
I registered with
http://epsonexperts.com, located the manual for the TM88lll, went to page 2 of the users manual, it shows the dip switch table settings for serial connection printers.
(2) I then unscrewed the bottom metal plate underneath the printer (It has 2 dip switches 1 and 2), under dip switch 1 - I set it according to the transmission speed settings on the manual which states dip switch 1 - button 7 and 8 should be switched on, and that should increase it to rate 38400 from 9600
I then switched the printer back on with the feed button depressed, which confirmed that the dip switch settings had changed. I then went back to the port settings, changed the baud rate to 38400 and restarted the computer and printed off a test page at least 10 times faster than before