Kent's Emulated GS
by Kent Dickey
"KEGS is an Apple //gs emulator for X windows, but optimized for HP
workstations. KEGS is now portable to two other platforms-- Linux on
Intel x86 and Linux on PowerPC machines. KEGS was originally written
for HP Unix workstations using a hand-coded assembly language
interpreter loop. To open KEGS up to a wider audience, I recoded the
assembly parts into a C-only version, which can now be compiled and run
on other platforms. The Linux port was very easy since only a few dozen
lines of code needed to change. See README.compile.
"KEGS uses X-Windows for its display (you can send the display to another
machine) and uses the built-in audio on HP workstations to emulate all
Apple //gs sounds. It supports limited serial port emulation through
sockets. Audio does not work under Linux yet.
"The ROMs and GS/OS (the Apple //gs operating system) are not included
with KEGS since they are not freely distributable. KEGS is a little
user-hostile now, so if something doesn't work, let me know what went
wrong, and I'll try to help you out. See my email address at the end of
- Fast 65816 emulation
- Assembly version: about 8MHz on a 712/80, and 17-20MHz on a C180.
- C version: about 4MHz on a 712/80, 12MHz on a 266MHz Pentium II.
- About 13MHz on a 240MHz 604e PowerCenter 240 running MkLinux.
- Emulates low-level 5.25" and 3.5" drive accesses (even nibble-copiers work!).
- Emulates classic Apple II sound and 32-voice Ensoniq sound.
- All sound is played in 16-bit stereo at 48KHz. (Not on Linux, yet).
- Emulates all Apple //gs graphics modes, including border effects.
- Can handle mixed-displays (superhires at the top, lores at the bottom).
- Always does 60 video updates per second.
- Mouse and joystick support (although the joystick is hard to use).
- Emulates all Apple //gs memory "tricks" for full compatibility.
- Low-level ADB keyboard and mouse emulation enables Wolfenstein 3D to run.
- Clock chip emulation makes the Unix time available to the Apple //gs.
- Emulated battery RAM remembers control panel settings.
- Limited SCC (serial port) emulation to enable PR#1/2 IN#1/2 and other
- serial programs to work, but it is still a bit buggy.
- KEGS always emulates a 4MB Apple //gs. I may make the amount of Apple //gs memory a command line option in the future.
- KEGS is so accurate, even the built-in ROM selftests pass (you must be in 2.5MHz speed mode to pass the self-tests).
KEGS for HP-UX and Linux [Homepage]
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