Apple Pascal

Most Apple II users think of DOS, Integer BASIC, and Applesoft BASIC when they consider the operating system and languages used to run the early machines. But not too long after the Apple ][+ was introduced Apple released it's own derivative of the UCSD P-System: Apple Pascal.

Although Apple DOS 3.3, ProDOS, and Apple Pascal share the same low-level format for floppy disks (16-sector, 140K format for 5.25 inch disks; 800K for 3.5 inch disks) and access to peripheral cards in I/O slots, the similarity ends there. Apple Pascal uses the UCSD file directory format (limited to 77 files per volume) and a separate BIOS.

The Pascal Compiler generates P-code, which is interpreted at run time. Relocatable 6502 assembly language routines can be written using the Assembler and linked into Pascal programs for execution.

One of my favorite books, Randal Hyde's p-Source: A Guide to the Apple Pascal System, describes how to use the methods provided for adding customized drivers to enhance the P-code interpreter itself. (The book revealed a lot of other fascinating secrets as well.)

The Archives

I had a lot of fun between 1981 and 1987 writing programs and customizing the system to work with my Mountain Hardware CPS card (and later to use the Apple IIgs hardware). On this page I'm making available some of the source code and executables. Unfortunately, there is no "Shrinkit" format for Apple Pascal.

I have copied groups of programs on 800K and 140K disks and created disk-image archive files. (If you can think of a better way to make the information available, please write me at the address found on the bottom of this page.) After you copy the archive to your system, you can run Shrinkit to restore it on a 3.5 inch disk; that disk should work in your Apple Pascal system.

Since I'm not sure how many folks are interested in using these disk images, I haven't tested them to see if there are ties to my system that will make them difficult for others to use. If you run into problems (say, a reference to a missing file), send me e-mail and I'll try to help you out.

Of course, you must own Apple Pascal to use any of these archives.


  • If you are using Netscape Navigator, you will probably need to ``shift-click'' on the links in order to get them to download to your system rather than display as garbled text.

  • You can list the software archive (.SDK) and description (.txt) files in directory format.

140K (5.25 inch) Apple Pascal disk containing text files of procedures and functions that are handy to use when programming in Pascal. Some are combined into a UNIT called ToolStuff.

140K (5.25 inch) Apple Pascal disk containing text and code files for software that will map multiple logical disk volumes onto a single physical Apple Pascal disk volume.

800K (3.5 inch) Apple Pascal disk containing text and code files for various file access utilities.

800K (3.5 inch) Apple Pascal disk containing text and code files for program development tools, including programs to generate cross reference listings of Pascal and Assembler source code and a program to disassemble both p-code and 6502 assembly segments in a code file.

800K (3.5 inch) Apple Pascal disk containing text and code files for various programs that allow you to explore the Apple Pascal system, including a UNIT to access system variables, a program to print information about code files, and assembly language code of the TREESEARCH function dropped after Apple Pascal 1.2.

800K (3.5 inch) Apple Pascal disk containing text and code files for software related to Pascal I/O, including various drivers and an assembly language routine to access the Apple IIgs clock.

For Further Information...

Here are some interesting links related to Apple Pascal:

Find anything wrong with this page...bad spelling, corrupt links, misstatements of fact, etc.? Is there anything that can be improved? Please let me know by following the e-mail link at the bottom of this page.

Return to Dave Tribby's Apple II Page
or the Apple II page maintained by Terry Allen

This page was last modified January 14, 1999, by Dave Tribby