mic1 is a Java-based simulator which implements the Mic-1 microarchitecture described in Chapter 4 of Andrew S. Tanenbaum, Structured Computer Organization, Fourth Edition (Prentice-Hall, 1998).  The software available here is designed to support instructors and students using this text. Additional supplemental material for this and other Tanenbaum texts is available from the author's site.

mic1 was written by Ray Ontko and Dan Stone with advice from Andrew S. Tanenbaum and support from Prentice-Hall.

Send comments, suggestions, enhancements to Ray Ontko (rayo@ontko.com).

Distribution 1.0e production release (Monday, 24-Apr-2000 08:36:04 EST)

• For Unix-based systems: compressed tar archive 173K
• For Win95/98/NT systems: self-extracting ZIP archive 289K

Other releases (historical and developmental) are also available for downloading.

The mic1 software is written in Java and requires the Java Development Kit (JDK) 1.0 (or later) to run. Java technology is available from Sun or one of its technology partners. Visit http://www.java.sun.com/ (and follow the "Products" link) to find a suitable distribution.

Note: You may be able to get mic1 to work on other operating systems or with other Java runtime environments. Problems have been reported with Symantec Java under Win2K, but our investigations were not conclusive. If you are able to get it running in that environment, let me know (rayo@ontko.com).

The mic1 microassembler utilizes the CUP Parser Generator for Java, written by Scott Hudson. All other programs and modules are written directly in Java and are intended to be compatible with JDK 1.0 and later.

The mic1 software is distributed under the terms of the GNU General Public License.  The source code is included in the distribution.

Documentation (included in distribution)

• mic1 User Guide
• Release Notes
• Frequently Asked Questions (FAQ)
• IJVM Assembly Language Specification
• Micro-Assembly Language (MAL) Specification
• mic1sim manual page
• mic1asm manual page
• ijvmasm manual page

Sample Files (included in distribution)

• echo.jas, a simple IJVM program demonstrating input and output.
• add.jas, a more complex IJVM program demonstrating method calls.
• ijvmtest.jas, a program to test the IJVM instructions.
• mic1ijvm.mal, a microprogram for the mic1 architecture which implements a simplified Java Virutual Machine called IJVM.
• ijvm.conf, a configuration file for the IJVM assembler. This file maps op codes to mnemonics and instruction formats.

• a simple Mic-1 simulator (mic1sim) which allows the user to simulate the execution of a Mic-1 microprogram,
• a simple Mic-1 assembler (mic1asm) which translates a text-file containing Mic-1 microassembly language (MAL) into a binary file of Mic-1 microinstructions, suitable for loading into the mic1 simulator control store,
• a sample Mic-1 microprogram which interprets a modified (integer-only) subset of Sun's Java Virtual Machine (JVM) instruction set architecture (ISA) (which we shall call IJVM),
• a simple IJVM assembler (ijvmasm) which translates a text-file containing IJVM into a binary file of IJVM instructions, suitable for loading into the main memory of the mic1 simulator, and
• a sample IJVM program which can be used to demonstrate the operation of the Mic-1 microprogram using the mic1 simulator.

Some possible projects (in increasing order of complexity):

• Write a program in IJVM. Demonstrate that your program works correctly using the IJVM assembler and the Mic-1 simulator.
• Add a new feature to the IJVM assembler.
• Add a new instruction to IJVM and implement it as an extension to the Mic-1 IJVM microprogram. Modify the IJVM assembler to correctly identify and generate code for your new instruction. Demonstrate that your new Mic-1 microprogram correctly interprets an appropriate test program containing your new instruction.
• Write a microprogram in Mic-1 microassembly language.
• Add a new feature to the Mic-1 microassembler.
• Add a new register to the Mic-1 architecture.
• Implement a simulator for the Mic-2 architecture.
• Implement a simulator for the Mic-3 architecture.
• Implement a simulator for the Mic-4 architecture.

While several of these projects support the material covered in Chapter 4, The Microarchitecture Level, there are several that are applicable to other parts of the text. For example, there are a number which develop concepts introduced in Chapter 7, The Assembly Language Level.

Other Mic1 Software Links

• CIS360 tools, by Paul D. Amer, University of Delaware. This collection of tools was developed for the 3rd edition of this text.
• MIC-1 SIMULATOR, by Cantarella Alfredo, Di Guardia Pietro, Pennisi Sandro, Pulvirenti Alfio, students of Franco Barbanera, Dipartimento di Matematica e Informatica, University of Catania. Includes documentation in Italian and English. This is based on the mic1 code by Ray Ontko and Dan Stone.
• Mic-1 Simulator, Herbert Bonaffini. This appears to be a Windows-specific version. Does not include source code; use at your own risk.
• PROJECT: You don't need a fab to build your own CPU!, by Marco Aiello. An article with software.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

A copy of the GPL is available online the GNU web site:

  http://www.gnu.org/copyleft/gpl.html

Thanks to Adrian Llahana, John Miller, and Andy Tanenbaum for comments and suggestions on the software and documentation.

Special thanks to Alan Apt, Sondra Chavez, and Ana Terry at Prentice-Hall.

Eternal gratitude to Andrew S. Tanenbaum for creating a great text and inspiring us to create the software.