Technology: May 2024 Archives

Digital Equipment Corp. RL-02 disk drive

In February 1989, I flew to the UK for the first time, bringing with me a disk cartridge the size of a large deep-dish pizza (15" diameter, 2.25" height) with a capacity of 10MB. It had to fly as a checked bag in a shipping box. The cartridge, an RL-02K, would fit into a DEC RL-02 disk drive connected to a PDP-11/70, and it contained the software to manage a DR-11W interface to a VMEbus chassis, which provided the ARINC 429 interface to communicate with a Flight Management System being added to a British Airways Boeing 737 Ground Maintenance Simulator at the airline's Viscount House training center.

Bitsavers has tons of documentation on the RL-01/RL-02 drives. The wealth of detailed drawings and protocol documentation (the sort of thing that modern manufacturers don't release any more) enabled Christopher Parish to convert an RL-02 into the world's largest thumb drive, as he explains in a Hackaday video. Parish designed a controller card using an FPGA to interface to the drive and expose the data as a USB mass storage device. He can connect it to modern OSes but also to emulators running DEC's RT-11 OS.