DEC disk history
Started 1/94 -pb
Phil Budne <phil at ultimate.com>

$Id: dec.disks,v 1.31 2006/01/15 21:40:10 phil Exp $

The focus is on disks sold for use on DEC systems (whether
manufactured by DEC or not) not general market peripherals
(ie; the DSP SCSI line) manufactured by DEC.

Capacity is approx, (1K=1024 1M=1024K) some formatted, some unformatted
Geometry is (usually) physical (counts alternate sec & cyl)
 ~ on cylinder counts means average (zone bit recorded disk)

Transfer rates are (usually) avg sustainted rates to/from media.
 1K=1000, 1M=1000K, b=bits, B=8-bit bytes.

All hard disks 3600 rpm unless noted

Wanted:
 corrections & additions!!
 seek times (avg/min/max)
 rotational latency
 transfer rate
 origal mfgr & designation for non-dec disks
 interface type (ie; Massbus, MSCP) or controller type
 year of introduction (dec or orig mfgr)
 encoding?? bpi??

Old interfaces (removable unless noted)
=======================================

disk cap. sec/trk trk/cyl cyl notes
 (surf)

================ VAX730 IDC

R80 121M 31 14 559 dec built; winchester; SMD interface
 (RM80 with SMD/Massbus converter)

================ via PDP-11 RK-11, PDP-8 RK8

RK01 ? ? ? ? [on RK8] mfr: IOMEC (also sold as HP2870A)
 100TPI
RK02 1.2M 12* 2 203 Diablo model 30 low density (256B sect)
 avg seek: 70ms (15ms min)
 1500 rpm; avg rot delay: 20ms
 xfer: 22.2us/word
 1100 BPI max
 1-of-n select
RK03 2.5M 12* 2 203 Diablo model 30 high density (512B sect)
 avg seek: 70ms (15ms min)
 1500 rpm; avg rot delay: 20ms
 xfer: 11.1us/word
 2200 BPI max
 1-of-n select
RK04 1.2M 12* 2 203 low density (256B sectors)
 binary select
RK05(J) 2.5M 12* 2 203 1500rpm; RK03 cartridge;
 RK8 max xfer 1.44Mb/s (8.32us/wd 1.1??)
 seek: 50ms/10ms/85ms
 binary select
RK05F 5M 12* 2 203 1500rpm; fixed rk05; 2xRK05 to s/w

*16 sec/trk on pdp-8 (192 words/sector?)

================ via RK611 (Unibus)

RK06 13M 22 3 411 2400rpm; dec built
RK07 27M 22 3 823 2400rpm; dec built;
 xfer 538KB/s; lat=12.5ms
 seek: 36.5ms avg, 8.5ms min
 avg access 49ms
================

RL01 5.2M 40 2 256 2400rpm; 256B/sect; dec built; pack
 xfer 512KB/s; lat=12.5ms
 seek (ms) 55avg/15min/100max
 3725 BPI; 125 TPI
RL02 10M 40 2 512 2400rpm; 512B/sect; dec built; pack
 xfer 512KB/s; lat=12.5ms
 seek (ms) 55avg/15min/100max
 3725 BPI; 250 TPI

================ via PDP-10 RA10

RB10 20-100M 11 varied "Giant Bryant" disk
 (aka "MD10" Moby Disk???)
 1200rpm? av seek 110ms?
 6 to 20 platters; each w/ 2 arms
 20,971,520 to 104,857,600 36bit words
 xfer 22.us to 72us/w
================ via PDP-10 RC10;

RD10 2.5M 20 2 100 Burroughs disk
 1800(1735)rpm; 32*36b/sect
 fixed head; lat=17.6ms; xfer=2.7Mb/s
 (76000W/S; 13us/W)
 total of 512,000 36-bit words
 (4000 128-word blocks)
 200 tracks of 80 32W "segments"

RM10B 2.07M 30 1 90 Bryant drum; 64*36b/sect; xfer 7.9Mb/s
 @60Hz: 3450rpm, lat8.8ms
 @50Hz: 2870rpm, lat10.6ms
 total of 345,600 36-bit words
 (2700 128-word blocks)
 Drum surface was conical, and mounted
 vertically.

================ fixed head

RF/RS11 512K -- 1 128 1800rpm; fixed head

RS08 256KW -- 1 128 PDP-8 fixed head disk (RF08 ctrlr)
 128 fixed heads (1/track)
 3(+3 spare) timing tracks 
 word addressable
 2048 words/track; 1100 BPI max
 @60Hz: xfer 16us/wd
 access 16.9ms/250us/33.6ms
 @50Hz: xfer 19.2us/wd
 access 20.3ms/320us/40.3ms
 max density 1100BPI, NRZI recording

DF32 32KW -- 1 16 PDP-8 fixed head disk (13 bit words)
 word addressable; 2KW tracks
 @60Hz: xfer 32us/wd, avg access 16.67ms
 @50Hz: xfer 39us/wd, avg access 20ms
 max density 1100BPI, NRZI recording
 10" rack 10.5" high

 Upto 3 DS32 slaves can be chained.

================ via PDP-10 RP10; PDP-11 RP-11; PDP-8 RP08

RP01 5M 5 10 203 2400rpm; Memorex ("Mark I"?)
 pack [never released]
 seek (ms) 50avg/20min/80max; lat13.7ms
 xfer=837Kb/s
RP02 20M 10 20 203 2400rpm; Memorex 660 (Mark IV); pack
 seek (ms) 50avg/20min/80max; lat13.1ms
 xfer=1.8Mb/s. $25k c. 1969
RP03 40M 10 20 400 2400rpm; Memorex (Mark VI); pack

================ via PDP-6 270

5022 5.76MW 4/7 16 128/128 Data Products disk
 inner and outer zones
 each arm has heads for both
 128 (36 bit) word sectors

Massbus
=======
disk cap. sec/trk trk/cyl cyl notes

RP04 83M 22 19 411 pack; ISS-Sperry Univac (8430?)
 3500rpm? av seek 27ms?

RP05 83M 22 19 411 pack; Memorex; drive looks like RP06
 field upgradable to RP06

RP06 176M 22 19 815 pack; ISS/Memorex 677 "Mark XVI"
 ("Merlin"?) (clone of IBM 3330-II?)
 avg access 38.3ms; avg lat 8.3ms
 seek 30ms (avg), 10ms (min)
 xfer=825KB/s
 3600rpm

RP07 504M 50(30?) 32 630 ISS/Sperry Univac; winchester
 seek 23ms (avg) 3633 rpm?
 xfer=2.3MB/s (36-bit)/ 1.3MB/s (32-bit)

RP20 929M 24(25?) 30 1119(750?) two fixed spindles (on DX20?)
 seek 25ms (avg); xfer=1.3MB/s
 3500 rpm? (840000 128*36b blocks)
 Memorex 3652??
 dual Memorex 3650 (IBM 3350 clone)

RS03 512K 64 1 64 fixed head; 128B/sector
RS04/5 1M 64(32?) 1 64 fixed head; 256B/sector
 6ms access; spiral read
 32 blks/trk 2048 blks/cyl?
 3600rpm

RM02 67M 32 5 823 pack; CDC 9762; 2400 rpm
 xfer=6.4Mb/s (806KB/s); avg acc 42.5ms
 seek 30ms (avg), 6ms (min)
 avg latency 12.5ms
RM03 67M 32 5 823 pack; CDC 9762; 3600 rpm
 xfer=9.6Mb/s (1.2MB/s); avg acc 38.3ms
 seek 30ms (avg), 6ms (min)
 avg latency 8.3ms

RM05 256M 32 19 823 pack; CDC 9766
RM06 ?

RM80 124M 32 14 559 winchester (RA80 HDA)
 xfer=9.6Mb/s (1.2MB/s)
 avg access 33.3ms; avg lat 8.3
 seek 25ms (avg), 6ms (min)
 3600RPM

ML11A varies - - - solid-state (ram) disk; 2MB/s xfer
 1-31 arrays of 512 or 2048 blocks ea

MSCP/SDI
========
disk cap. sec/trk trk/cyl cyl notes

RA60 205M 42 4 2382 pack; seek 42 ms (avg);
 xfer=2.1MB/s (1.98?)
 3500 rpm?? 5 platters?

=== 5.25" FH?

RA70 280M 33 11 1507 
RA71 684M 51 14 1915
RA72 1G 51 20 1915
RA73 2G 70 21 2667

=== 19"

RA80 124M 31 14 546 dec; winchester; 3500 rpm?
RA81 446M 51 14 1248 dec; winchester; 3500 rpm?
 seek 28 ms (avg); xfer=2.3MB/s
RA82 608M 57 15 1423 dec; winchester

RA90 1.2G 69 13 2649
RA92 1.5G 69 13 3279

RC25 26M*2 42 4 302 "LESI" (Low End Storage Interconnect)
 1 fixed, 1 removable; CDC9457? ("Lark")
 Peak xfer 1.25 MB/s;
 Seek 10/35/55ms
 avg rotational latency: 10.5ms
 avg access: 45.5 ms

MSCP/DSSI
=========

RF30 143M 37 6 1320 5.25" HH
RF31 380M 50 8 1861 5.25" HH
RF35 852M 5.25" HH?
RF36 1.6G 5.25" HH?
RF71 390M 37 16 1320 5.25" FH
RF72 1G 50 21 1861 5.25" FH
RF73 2G 5.25" FH?
RF74 3.5G 5.25" FH?

=== ??

ESE20 120M 4 128 483 Solid state disk

Floppy
================================================================
disk cap. sec/trk trk/cyl cyl notes

RX01 256K 26 1 77 8" SSSD (IBM soft-sectored)
 128B/sect; 360rpm
 xfer 250Kb/s; lat 83ms
 seek (ms) 405avg/30min/790max
RX02 512K 26 1 77 8" SSDD (on-standard)
 256B/sect; 360rpm
 xfer 488Kb/s (61KB/s); lat 83ms
 seek (ms) 154avg/6min
 avg access 262ms

RX03 1M 26 2 77 8" DSDD (non-standard) -- not released

RX22

RX23 3.5" SCSI
 high 1.4M 18 2 80
 double 720K 9 2 80
 single 360K 9 2 40

RX26 3.5" SCSI
 extra 2.8M 36 2 80
 high 1.4M 18 2 80
 double 720K 9 2 80 
 single 360K 9 2 40


RX33 5.25" Teac FD55-GFR-17U MFM?
 extra 1.2M 15 2 80
 high 720K 9 2 80 DSDD
 double 400K 10 1 80 SSDD (RX50 compat?)
 single 360K 9 2 40 DSSD

RX50 400K 10 1 80 5.25" single sided, dual drive
 FM encoding

MFM "ST506/412 interface" (on RQDX{1,2,3})
==========================================
disk cap. sec/trk trk/cyl cyl notes

=== 5.25" FH
RD50 5M 17 4 153 Seagate ST506 seek 85/3?/??
RD51 10M 17 4 306 Seagate ST412 seek 85/16.6?/??
RD52 31M 18 7 480 Quantum 540 / ATASI 3046 (also Evotek?)
RD53 71M 18 8 1024? Microp 1325 (or 1335) w/ jumper at J7
RD54 156M 17 15 1225 Maxtor XT-2190D

=== 5.25" HH
RD31 20M 17 4 615 ST225 seek (ms) 65/20/150
RD32 40M 17 6 820 ST251(-1*) seek 40(28*)/8/70
 ST277R(-1*) [MFM format] 40(28*)/8/70
RD33 71M Microscience HH-1090 [Never released]

SMD disks popular on VAXen (Winchesters unless noted)
=====================================================
disk cap. sec/trk trk/cyl cyl notes

A9300 248M 32 19 815 Ampex 9300; removable
A330 262M 32 16 1024 Ampex Capricorn 330

CDC9720 275M 48 10 1147
CDC9730 268M 32 10 823 removable
CDC9762 65M 32 5 823 removable; (also RM03) [phys 80M?]
CDC9766 256M 32 19 823 removable; (also RM05)
CDC9775 839M 32 40 843

M160 132M 32 10 823 Fujitsu 160
M2351 337M 46 20 842 Fujitsu Eagle 19"
M2351A 337M 48 20 842 Fujitsu Eagle 19"
M2351AF 337M 48 20 842 Fujitsu Eagle 19" w/ 3 fixed heads
M2361 549M 64 20 842 Fujitsu Super Eagle 19"
M2361A 549M 68 20 842 Fujitsu Super Eagle 19"

NEC800 800M 66 23 850
NEC2363 1G 64 27 1024

SCSI disks (Winchesters unless noted)
=====================================
disk cap. sec/trk trk/cyl cyl notes

=== 5.25" FH

RZ55 325M Micropolis 1578-15
 or maxtor xt-4380sb2?
RZ55L
RZ56 650M 54 15 1632 Micropolis 1588-15
RZ56L
RZ57 1.01G 71 15 1925 Micropolis 1598-15
RZ57I
RZ57L
RZ58 1.3G 85~ 15 2117 5400rpm? Micropolis 1908?
RZ59 8.9G 193 18 5111

=== 5.25" FH?

RZ72
RZ73 2.0G 71 21 2621
RZ74 3.57G 67~ 25 4165

=== 3.5" HH?

RZ22 51M 33 4 776 Conner CP350
RZ23 102M 33 8 776 Conner CP3100-1
RZ23L 118M 39~ 4 1524
RZ24 205M 38 8 1348 Conner CP3200; 3500rpm?
RZ24L 240M 66~ 8 1818 Quantum LPS-240S?
RZ25 416M 62 9 1492
RZ25L 523M 79~ 8 1891
RZ26 1.05G 57 14 2570 5400rpm?
RZ27 1.6G 143~ 16 1366
RZ28 2.1G 99~ 16 2595 DEC manufactured
RZ28B 2.1G 82~ 19 2626 Seagate ST12400N; 5411 rpm; seek 10/2/22
RZ29 4.2G 113~ 20 3720 Quantum?

================ 5" HH?

RZ31
RZ33 ??
RZ35 832M 57 14 2086

================ 5" FH??

RZ55 332M
RZ56 635M
RZ57 1G
RZ58 1.3G

================ 5" FH

RZ73 2G
RZ74 3.57G

================ CD-ROM (IDE/ATAPI)

RRD20? PHILLIPS 2X IDE/ATAPI CDROM
RRD32? 32X ATAPI CD-ROM
RRD37 Toshiba XM-5201B

================ CD-ROM (SCSI)

RRD40 LMS CM 210 (no audio)
RRD42 1X Sony CDU-541
RRD43 2X Toshiba XM-4101B
RRD44 2X Toshiba XM-3401B "high performance"
RRD45 4X Toshiba XM-5401B
RRD46 12x Toshiba XM-6302B (or XM-5701B?)
RRD47 32x Toshiba XM-6201B
RRD50 Philips/LMSI CM100 (no audio)

================ Optical WORM

RWZ01 288M 31 1 18751 Erasable Optical 5.25"
 (Sony) EDM-1DA0/1DA1/650/600

RWZ21 WORM 3.5" (MO)

RV20 6GB? Optical WORM 12"
RSV20 Optical WORM
RV60 12"
RV64 Jukebox (RV20 based)

RWZ52 1.2G 5.25"; rewritable; 600MB/side
 HC: acc 36ms; r 1.6MB/s; w 0.53MB/s
 LC: acc 38ms; r 1.0MB/s; w 0.33MB/s

RVZ72 6.55G tabletop 12" write once; SCSI
 access 600ms; read 900KB/s; w 400 KB/s
RV720 78GB deskside jukebox w/ 1 drive, 12 disks
RV730ZB 438GB datacenter jukebox w/ 2 drives; 67 d.
RV730ZD 308GB datacenter jukebox w/ 4 drives; 47 d.
 

Decimage Express v2? LMS 5.25"/12" WORM 

Solid-state disks (SCSI?)
=========================

"disk" cap. sec/trk trk/cyl cyl notes

EZ51 104M 33 9 776
EZ54 418M 62 10 1492
EZ58 835M 20 10 8353