Simon Williams wrote: > Bill Garber wrote: > > > What is the "REAL" ProDOS system file? > > AFAIK P8 _is_ ProDOS version 2.0.3, whereas the file named ProDOS in > GS/OS is some kinda launcher... The file called PRODOS in the root directory of a GS/OS or ProDOS-16 boot disk is the operating system loader for GS/OS or ProDOS-16, not the ProDOS-8 operating system. The boot sector is configured to look for a file called PRODOS in the root directory, so Apple had to use this name for the GS/OS or ProDOS-16 loader in order to keep using the same boot sector code. The P8 file in the SYSTEM directory is the standard ProDOS-8 kernel. For IIgs System 6.0.1, this will be ProDOS-8 2.0.3, and it is exactly the same file as would be distributed on an 8-bit system disk, except for its filename and location. You can copy this file to another disk's root directory, rename it as PRODOS, and the disk will be able to boot. The GS/OS "PRODOS" file loads the next stage of the operating system (START.GS.OS if I remember the name right), which is also located in SYSTEM. In recent versions of GS/OS, the PRODOS loader checks to see whether the user has pressed the "8" key, in which case it loads P8 instead of START.GS.OS, going straight into ProDOS-8. One further comment regarding ProDOS-8 2.0.3: ProDOS-8 version 2.0 and later requires a 65C02 or later processor. It won't work on a II+ or unenhanced IIe (unless the processor has been replaced with a 65C02, 65802, 65816 via an adapter, Zip chip, etc.) If you only have a 6502 processor, you have to run ProDOS-8 1.9 or earlier. [All of the above was from memory, now extremely rusty as I haven't actively used any Apple II since 1996.] -- David Empson dempson@actrix.gen.nz