RL0x disk drive
|RL01 / RL02|
|Manufacturer:||Digital Equipment Corporation|
|Drive Controller(s):||RL11 (UNIBUS)|
|Capacity:|| 5.2 Mbytes (formatted) (RL01)|
10.4 Mbytes (formatted) (RL02)
|Transfer Rate:|| 512 Kbytes/sec|
3.9 usec/word (peak)
|Average Access Time:||67.5 msec|
|Revolutions Per Minute:||2400|
|1/2 Revolution Time:||12.5 msec|
|One Track Seek Time:||15 msec|
|Average Seek Time:||55 msec|
|Maximum Seek Time:||100 msec|
|Head Switching Time:||8 msec (maximum)|
|Tracks Per Surface:|| 256 (RL01)|
|Sectors Per Track:||40|
|Words Per Sector:||128|
|Tracks Per Inch:|| 125 (RL01)|
|Density:||3725 bpi (maximum)|
|Recording Method:||Modified Frequency Modulation (MFM)|
|Start Time:||40 seconds|
|Stop Time:||30 seconds|
|Physical Size:||19" W x 10-1/2" H x 25" L|
|Power Consumption:||160W (running); 550 VA (starting)|
The RL01 is a 5MiB drive, and the RL02 is 10MiB; the latter is a high-density version, with twice as many tracks per surface, but otherwise mostly identical.
To keep the heads properly aligned on the tracks, it used a servo system driven by servo data written on the pack (along with sector headers) at the factory. Packs cannnot be low-level re-formatted in the field, and are not compatible with both drive types.
Early versions of the drives included a set of brushes that swing out over the platter on start-up; these were deleted in later versions.
Up to 4 drives may be attached to a single controller; the drives are connected serially, with a terminator on the 'out' port of the last drive on the string.
The UNIBUS contoller is the RL11, a single hex card. The QBUS controllers are the RLV11 and RLV12; the former consists of two quad cards, and needs a QBUS backplane with CD interconnect; the latter is a single quad card, and is also the Q22 version.
4.3 BSD disktab
rb02|RB02|DEC RL02 on 730 IDC:\ :ty=removable:se#256:ns#40:nt#2:nc#32:\ :pa#15884:ba#4096:fa#1024:\ :pb#4480:pc#20480:
Emulating the RL02
Reinhard Heuberger has created an open source emulator for the RL02 (and RL01) using a Terasic DE0-Nano Altera Cyclone IV FPGA board, extended with necessary interfacing hardware and an SD card slot. The emulator can be used with a real PDP-11, for example.