With the new version 1.2 FDC+ firmware update and version 1.3 of the FDC+ Serial Disk Server, the FDC+ now supports two 8 Mb drives on your Altair. I have created a version of CP/M to use this new disk format. CP/M drives A and B are 8Mb drives and drives C and D are standard Altair 8" floppy drives.
The 8Mb drives are hosted on the serial disk server that can be connected to the Altair FDC+ board. The 8Mb drive looks like a standard Altair floppy drive but with 2048 tracks instead of 77 tracks. See “Requirements” below for the required firmware and software versions for the FDC+ and serial disk server.
CP/M is also patched to make the "user" construct of CP/M 2.2 more user-friendly (pun intended) to help organize the run away file collection that tends to develop on a CP/M hard disk. The update provides the following specific features:
1) The current user number shows in the CP/M prompt (e.g., "A0>" or "A5>", or "B12>").
2) If a typed command is not found on the default user/drive combination, then drive A for the current user is searched, then drive A for user 0 is searched. By making drive A user 0 the repository for system files, most every command will run as expected even when in a different user/drive combination.
Requirements:
FDC+ Firmware version 1.2 or newer
FDC+ Server version 1.3 or newer
Download these latest versions at https://deramp.com/downloads/altair/hardware/fdc+/