Lower Case Driver
RS Catalog # 26-1104 / Copyright 1979

Note from Dave Keil (who created this CAS image)

ULCBAS is the lower case driver for cassette BASIC.

ULCDVR is the lower case driver for Disk systems. This driver can not be executed from BASIC, it must be converted to a /CMD disk file using the
TAPEDISK/CMD utility included in TRSDOS 2.3.
The load and execution addresses are:

load = 7000H - 73FFH, execution = 7000H