SIM2051 is an Elnec AT89C2051 simulator and programmer.
Discontinuation and support
Elnec’s discontinued-products archive lists discontinuation in 12/2001. The archive lists 12/2005 in its software-support date field; check Elnec for current status. Its listed replacement or solution is without replacement. Replacement does not guarantee identical device coverage.
Check the exact device, package, programming operation, adapter, software version and computer interface in the manufacturer's documentation before use.
Sources: Elnec discontinued products and support; Elnec software and manuals.