Bryan Parkoff wrote: > I don't see that ROM Disk is used by Apple Computer, Inc. If it does, > where can I obtain the information? Apple never supplied any hardware which provided support for the ROM disk, but there are third party products that support it. One example is the OctoRAM ESP card, which is a piggyback card that attaches to the OctoRAM. The OctoRAM supports up to 8 MB of RAM using 30 pin SIMMs. The OctoRAM ESP provides an additional 512 KB of battery backed static RAM, which is mapped into banks F0 through F7. The driver has to be loaded into the card from disk, but after the next restart it appears as a volume called ROM5, with about 510 KB of storage capacity. There is a jumper which can be used to write protect the card after the appropriate data has been written to it, and the battery preserves the contents while the power is off. The driver is located at the start of bank F0. The slot 5 firmware recognises the presence of a ROM disk by looking for the string 'ROMDISK' at location F00000, and the driver entry point is immediately after that. The details are in the IIgs Firmware Reference. The main problem I had with my OctoRAM ESP is that the NiCd battery was unreliable, so I ended up removing it from the card and wiring in my own AA battery pack with separate Nicads, which I attached to the inside of the IIgs case. I also found it to be of limited use due to the small capacity: 512KB isn't enough for a GS/OS boot disk, but it might be sufficient for ProDOS-8. If the write protect jumper is connected, it cannot be used for some software (such as AppleWorks) which requires write access to the boot disk. -- David Empson dempson@actrix.gen.nz