ucsd-psystem-vm 0.11


SourceForge.net
Logo

This page is hosted by SourceForge: see also the Project and Statistics pages.

The ucsd-psystem-vm package is a portable virtual machine for the UCSD p-System.

[ Download | Aegis Repo ]

You could support this project with a donation.

About This Project

The ucsd-psystem-vm project is a portable virtual machine (p-code interpreter) for the UCSD p-System. It supports execution of Apple ][ Pascal programs, it can even display TurtleGraphics using X11.

This is a re-packaging of the excellent p-interp program by Mario Klebsch.

Disk Images

In order to do anything useful, the virtual machine needs disk images containing the UCSD p-System operating system files and utilities. You can build your own disk images using the ucsd-psystem-os project, straight from the II.0 sources.

The ucsd-psystem-os project's Download page has a number of links to the sources for different UCSD p-System versions.

Ancient History

The UCSD p-System is a portable operating system that was popular in the early days of personal computers, in the late 1970s and early 1980s.

Like today's Java, it was based on a “virtual machine” with a standard set of low level, machine language like “p-code” instructions that were emulated on different hardware, including the 6502, the 8080, the Z-80, and the PDP-11. In this way, a Pascal compiler that emitted p-code executables could produce a program that could be run under the p-System on an Apple II, a Xerox 820, or a DEC PDP-11.

The most popular language for the p-System was UCSD Pascal. In fact, the p-System operating system itself was written in UCSD Pascal, making the entire operating system relatively easy to port between platforms.

By writing a p-code interpreter in the platform's native assembly language, and a few minimal hooks to operating system functions for the file system and interacting with the user, you could move a p-code executable from another system and run it on the new platform. In this way, the p-code generated on one computer could be used to bootstrap the port of the p-System to another computer.

From the Jefferson Computer Museum web site.

See Also

Jefferson Computer Museum
This site has links and history for the UCSD p-System.

Mailing List
This Yahoo! group is devoted to UCSD Pascal.

Search Google
You make like to search Google for more UCSD p-System information.

Sister Projects

UCSD p-System File System: You can mount UCSD p-System disk images as Linux file systems.
UCSD p-System Operating System: The ucsd-psystem-os project contains the II.0 source files (and some bug fixes) plus a Makefile that uses the cross compiler to build the sources, and the file system tools to build working disk images that can be executed using the virtual machine.
UCSD p-System User Manual: A modern reconstruction of the UCSD p-System II.0 User Manual is available as HTML. It includes complete system documentation for the p-machine, file formats, the Pascal dialect supported by the compiler, and more.
UCSD p-System Cross Compiler: You can cross compile your UCSD Pascal code on Unix to create p-Machine object code. By using a cross compiler you can boot-strap a native system by first cross compiling, and then re-compiling with the native compiler.

The ucsd-psystem-vm package is freely distributable under the terms and conditions of the GNU GPL. There is more Software by Peter Miller at his home page.

This page has been accessed approximately times since 18-Sep-2010.