PD Zmodem v1.22 is a new DOS Zmodem program
 + full Public Domain status, including
   commercial use
 + support of any IBM compatible serial
   interface, using any IRQ up to #15
 + FOSSIL support
 + high throughput, especially with ISDN;
   optimum throughput on bad lines due to
   calculation of the best data block size
 + all standard Zmodem functions
 + ZedZap support (8k data blocks)
 + optional transfer of whole directory
   trees
 + chat function
 + automatic cps rate and transfer time
   control
 + time synchronization
 + minimum system load under OS/2 or DesqView
 + choice of English or German user interface

