Unknown iCOM Dual FDD Enclosure Wondering what that blue connector is for???
From; Mike Douglas
Looks like an FD-3812 or related unit. Your cabinet is missing the controller board. See the attached pictures. The S-100 board in the computer is not actually a controller, just a buffered data interface between the FD-3812 and the Altair. The board in the computer also has a boot ROM for the drive. The controller board in the drive cabinet controls all drive functions. It is soft sectored, double density instead of hard sectored like the original Altair drives. It ran "FDOS" from iCom/Pertec.
and from Tom Sanderson
The drive cabinet looks like an iCOM 3712 with the internal controller and S-100 interface missing. See: http://www.virtualaltair.com/virtualaltair.com/vac_icom_3712.asp
The drives are Shugart compatible (50-pin interface), however there are at least six configurations (see manual schematic). The revision like 03 or 06 is stamped on the board after the schematic number. The user could have changed the configuration based on the schematic table.
The drives might work with a Tarbell or other 8-inch controller. The drives are not compatible with MITS controllers, but the mechanical parts, especially the plastic door and bezel fir MITS drives are scarce. Check the door for cracks and be careful to protect the aging plastic.
Pertec bought iCOM and MITS to form Pertec Microsystems Division. The Pertec people that MITS interfaced with were mostly former iCOM employees. The idea was to protect the market for 2/3-height drives.
The iCOM 3712 (SSSD) and 3812 (SSDD) drive subsystems with an internal controller. The drive cabinet with controllers interfaced to a mainframe using an interface board with a boot prom. There were more interface boards than just S-100/Altair buss. Boot proms for iCOM FDOS and iCOM Debbi BASIC came from iCOM. CP/M & the CP/M boot prom came from Lifeboat
ICOM Real Time Operating System (RTOS) was killed by Pertec near completion, and Manager Ed Levenberg and the RTOS team were forced to do maintenance on the Altair Accounting Software.
The 3712 subsystem was a replacement for the iCOM FD360 (SSSD) cabinet. The improved 3712 chassis and modular power supply were used in the 3812 (SSDD) and the MITS 3202 (SSSD)