View Full Version : Altair FDC+ Enhanced Floppy Controller Update

February 28th, 2016, 09:52 AM
I have released firmware version 1.1 for the Altair FDC+. The primary purpose of the update is to allow the end user to modify the step rate generated by the controller.

The update can be downloaded from the FDC+ support page at http://deramp.com/fdc+support.htm.

From the release.txt file:

Added a monitor option to modify the step rate (step time) for non-Altair drives.

Added a monitor option to modify the index offset for the Shugart 8" as Altair drive type. A properly aligned Pertec drive (i.e., an original Altair drive) places data 360us later following a sector pulse than does a properly aligned Shugart drive (and most other brands). To allow interchange of disks between a Shugart 8" and Altair/Pertec drive, this 360us offset is hard-coded in firmware release 1.0. The new menu option allows changing this offset for two reasons: 1) To allow use of a direct-connect Pertec drive (i.e., no Altair drive cabinet). In this case, the offset should be set to zero. 2) To allow adjustment of sector-to-data timing to pull data off a disk written on an improperly aligned drive.

Added the Head Current Switch output signal (pin 2 on the IDC-50 cable) for the Shugart 8" as Altair drive type. This signal is used with the Altair controller, drive, and software, however, the Shugart 80x drives do not require this signal. For this reason, it was not output in firmware release 1.0. However, other Shugart 80x compatible drives do expect this signal, so it has been added.