AST RESEARCH TECHNICAL BULLETIN TB-0296 9-22-87 HOTSHOT 286 AND REX.SYS 1.0 The Hotshot 286 does not work with the version of REX.SYS that was on Superpak 5.02+1.10. Using version 1.0 of REX.SYS causes the system to lock up after REX.SYS is executed in the CONFIG.SYS. Replacing REX.SYS version 1.0 with version 1.11, corrects the problem. REX.SYS version 1.1 is available on SuperPak 6.0 and above.