NuBASIC4 by Simon Rowe is an Extended BASIC with disk commands, and works with both serial and IEEE-488 devices. Basic 4.0 is a set of additional commands added to the regular set available in the standard Basic 2.0 language.

Requirements: VIC-20 with 8K in BLK5, VIC-1112 optional

SYS 64802 to start the extension - Thx Jbevren