Atlas - an 1103A emulator for UNIX systems

Atlas is an emulator for the Univac Scientific 1103A. In addition to
implementing all 41 basic instructions of the CPU, including repeat (RPjnw),
Atlas also simulates the program interrupt feature. The emulator runs as an
interactive, command line program and interprets binary 1103A machine code
stored in simulated core/drum memory. Facilities provided by the emulation
include direct entry of machine code in octal form, breakpoints, disassembly,
and manual step debugging. Simulated input/output devices include a paper tape
reader, a paper tape punch, and an electronic typewriter.

The emulator is written in C and should be portable to a large number of UNIX
systems. It requires a compiler that supports two C99 extensions to the C89
standard: 64 bit integers (unsigned long long) and C++ -style comments (//). The
emulator currently runs on Linux (gcc or Intel cc for IA-32), SunOS (Sun cc or
gcc for SPARC), and Darwin (gcc for PowerPC).


http://insar.stanford.edu/~lharcke/programming/