Those of you who happily use the ‘old’ MCS51 assembler will be pleased to know that its dedicated file format can now be accepted by the popular 27C256 Emulator published in the January 2001 issue of Elektor. All you need is the free software update described in this article.An EPROM emulator is likely to remain a useful tools for quite some time to come, because it allows users to debug and correct programs intended to run from EPROM, without going through the tedious and time consuming process of erasing and reprogramming an EPROM after any small change to the target program. The emulator’s alternative to this drudgery is simple: edit the source code file, assemble, download and then restart the target system. The January 2001 issue of Elektor Electronics contains an article describing how to build such an EPROM emulator yourself. Although primarily intended for the popular 27C256, this emulator will also handle the 27C64, 27C128 and, if necessary, the 27C512.