RP04 disk drive

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RP04
Manufacturer: Sperry Univac ISS (basic drive), Digital Equipment Corporation (electronics)
Drive Controller(s): RH11 (UNIBUS)
Capacity: 88 Mbytes
Transfer Rate: 2.5 usec/word
Average Access Time: 36.3 msec
Revolutions per Minute: 3600
1/2 Revolution Time: 8.3 msec
One Track Seek Time: 7 msec
Average Seek Time: 28 msec
Maximum Seek Time: 50 msec
Total Surfaces: 19
Tracks per Surface: 411
Sectors per Track: 22
Words per Sector: 256
Density: 4040 bpi (maximum)
Recording Method: Modified Frequence Modulation (MFM)
Physical Size: 31" W x 40" H x 32" L
Weight: 600 pounds
Power Consumption: 660 VA per phase (running); 3300 VA per phase (starting, 10 seconds max)


The RP04 was the successor to the RP03 multi-platter large disk drive. It used a pack compatible with the IBM 3336 pack, used on the IBM 3330 drive.

The actual drive was produced by the Information Storage Systems (ISS) division of Sperry Univac, and OEM'd by DEC, who added interface electonics.

It was the first large drive to use the MASSBUS bus; thus, it did not have a specific device controller, but used the appropriate MASSBUS controller. A maximum of 8 drives were supported per controller.