.P00 File Format

Introduction

PC64, a Commodore 64 emulator for the PC, keeps each file of a C64 disk as a file of its own on the PC's disk. A C64 file name can hold characters a PC file name cannot, so the real name goes in a 26-byte header and the PC file gets a name made of the letters and digits of it. The extension is the file's C64 type and a counter: .p00 is a PRG, .s00 a SEQ, .u00 a USR, .r00 a REL, .d00 a DEL; a second file of the same name is .p01, and so on.

The explorer recognises the file by its header, which starts with C64File and a zero byte, and not by the extension. It shows the header and the data; the data of a P00 is a whole .PRG file with its load address, and opens in the .PRG viewer. A S00 opens as text converted from PETSCII; the others open as bytes. The type letter is taken from the extension; a file whose extension is not one of the five (.p01 and up, or a renamed file) is read as a PRG. Only the five 00 extensions are registered, so the others open through “Read as”.

Structure

The five extensions

Not described

Known, not yet covered

• Viewer: the file counter in the extension (.p01 and up) is not registered as an extension: only the five 00 names open by themselves.
• Viewer: a REL file's record structure is not decoded.

Unknown

• Reference and viewer: no real PC64 file was available. The layout follows the format as described and the P00 reader of the masswerk PET emulator on this machine (signature, name at offset 8, data from offset 26); it was tested on built files only.
• Reference: whether PC64 files from other versions of the program differ (the name padding, the bytes after the name).

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