MONUK01 only uses part of the 2K monitor space. Much of it contains unused code for OSI C2/C4 & Disk systems

MONUK01.ROM is th original UK101 monitor, quickly replaced with MONUK02/NewMon
MONUK01.asm is the assembler source for monuk01

MONUK01x32.ROM is a MONUK01 patched for 48x32 screen
MONUK01x32.asm is the slightly modified version of MONUK01