What is GAL/GEM 1.1?

GAL-GEM is a complete machine emulator for the GAL (Generic Assembly Language) and GEM (GEneric Machine) computation models, as described in “Computer organization: a top down approach” by Greg W. Scragg ...

GEM 1.0 accepts GAL assembly language programs, assembles and runs them on its CPU emulator. It displays continuously updated information about the current state of the program, allowing students to follow the execution at the machine level  This display includes:

• original GAL source code
• GEM machine language code
• cross referencing between the two sets of codes
• all data registers
• major system registers, including PC, IR, MAR, MBR, and CC.
• output window for user program output
• all referenced RAM locations
• highlighting of current instruction in both machine and assembly language windows

The assembler accepts the full GAL language. The emulation can be run at a reduced speed for ease of following the execution. Instructions can be executed singly, or even a  single cycle at a time. The user can choose between  binary, decimal or hexadecimal representation of the registers.  The PC can be reset, allowing repeated execution without reloading or reassembling. Simple I/O tools eliminate many of the I/O roadblocks to beginning assembly or organization students.  All windows are scrollable, allowing easy use with longer programs (or smaller displays).

Scragg, Greg. (1994). GEM manual. Electronic Document.

Download GAL/GEM 1.1 for Mac

Architecture

Motorola 68K

System Requirements

From Mac OS 7.0

Compatibility notes

Minimum Requirements

• 128 KB RAM
• System 7.0

Emulating this? It could probably run under: Basilisk II