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TU10 drive
Tape speed: 45 ips (Forward/Reverse)
150 ips (Rewind)
Size: 19"W x 26"D x 26"H
Weight: 150 lbs

The TU10 is a classic big tape drive from Digital Equipment Corporation, able to store 5-20 Mbytes on a 2400' 0.5" wide tape on a standard 10-1/2" reel. It supports 7-track operation at 200, 556, and 800 BPI, and 9-track at 800 BPI.

The tape transport utilizes a single capstan, with vacuum columns. The TU10 drive contains a fair amount of electronics, in the form of FLIP CHIP modules in a 19" wide wire-wrap backplane (mounted fore and aft in the drive itself).

It was first used with the PDP-10; to connect to UNIBUS PDP-11's, one of the TM11 series of magtape controllers is used. Details of the controller-Master interface are given here.

The TM11 controller connects to a 'Master' TU10 drive, which includes extra Flip Chip modules in the backplane; additional 'Slave' drives (up to seven) may be connected to the Master drive. The additional Flip Chips perform extra functions (e.g. CRC); they also convert the Positive bus from the controller to the Negative bus native to the TU10. The Master and Slave variants use the same wire-wrap backplane in the drive.

7-track/9-track Differences

The only significant difference between the 7-track and 9-track drives is the head. The Flip Chip suite is the same for both, since the per-track boards are all 9-track, and simply leave the last two bits disconnected when used with a 7-track head (see e.g. drawing # TU10-0-09, note "9 Track Only").

The drive does has to be able to indicate (to the controller) whether it is a 7-track or 9-track. Drawing # TU10-0-07 shows (center) an incoming signal on pin AJ1 of the M514 board (slot 21) called "7 CH"; that signal is intended to ground the input (which is otherwise pulled high), so there is an optional jumper to ground on the backplane to indicate 7- or 9-track (A21C2, per the Maintenance Manual, Appendix A.5).

In addition, certain operational delays are different; the M768 module contains configurable diode arrays to control these.

Drive Bus

The drive bus is a negative logic bus used between drives, but not between positive bus controllers and the first drive; in such cases the first (Master) drive contains logic to convert from the positive bus to the negative bus. This is the pinout of the negative bus:

Pin Signal Source
1-B1 WD 2 Controller
1-D1 WD 3 Controller
1-E1 WD 4 Controller
1-H1 WD 5 Controller
1-J1 WD 6 Controller
1-L1 WD 7 Controller
1-M1 WP Controller
1-P1 WD 1 Controller
1-S1 WD 0 Controller
1-D2 REC Controller
1-E2 SEL 0 Controller
1-H2 SEL 1 Controller
1-K2 SEL 2 Controller
1-M2 STOP Controller
1-P2 ALFA Controller
1-S2 LRCC Controller
1-T2 EMD Controller
1-V2 SET Controller
2-B1 RD 2 Drive
2-D1 RD 3 Drive
2-E1 RD 4 Drive
2-H1 RD 5 Drive
2-J1 RD 6 Drive
2-L1 RD 7 Drive
2-M1 RDP Drive
2-P1 RD 1 Drive
2-S1 RD 0 Drive
2-D2 REV Controller
2-E2 BOT Drive
2-H2 EOT Drive
2-K2 WRL Drive
2-M2 RWS Drive
2-P2 7CH Drive
2-S2 C556 Drive
2-T2 C800 Drive
2-V2 SKEW Drive
3-E2 DEN 5 Controller
3-H2 DEN 8 Controller
3-K2 SDWN Drive
3-P2 TUR Drive

Module Inventory

This table shows the number of Flip Chips of each type in the electronics backplane of the Master and Slave TU10's:

Master Slave Function
G050 1 1 Dual Gap Head Read Amplifier
G060 1 1 Mag Tape Compressor, 9-Track
G062 1 1 Mag Tape Peak Detector, 9-Track
G064 1 1 Mag Tape Slicer, 9-Track
G350 1 1 Mag Tape Write Driver
G741 2 2 Negative Clamp Load
G741-YA 1 1 Negative Clamp Load
G932 1 1 Capstan Servo Pre-Amplifier
G933 2 2 Reel Motor Amplifier
G9340 1 1 Brake Logic
G9341 1 1 Brake Actuator
M050 1 1 Inverter Driver
M100 1 Bus Receiver
M514 1 1 TU10 Transceiver
M640 1 Bus Driver
M763 1 1 9-Track Write Buffer
M765 1 1 9-Track Read Buffer
M767 1 1 Clock and Skew Delay
M7670 1 1 Forward BOT Timer
M7671 1 Bus Driver
M7672 1 Command Buffer
M7673 1 Data Checker
M768 1 1 Delay Selector
M769 1 1 Function Control
M890 1 1 Motion Control
M891 1 CRC and Write Gating
M892 1 Write and Gap Timing
M895 1 Read Timing
M896 1 CRC Checker
M958 1 Positive Bus Terminator
W726 1 1 Switch Filter

Module Locations

This table shows the Flip Chip modules locations in the integral backplane in Master drives:

Slot Top Bottom
1 G933
2 G933
3 G9341
4 G932
5 M908@ G9340
6 M958+
7 M929@
8 M640
9 M891
10 M7673
11 M7672
12 M892
13 M895
14 M7671
15 M100 M896
16 M7670
17 M903@ G741-YA%
18 M903@ G741%
19 M903@ G741%
20 M768
21 M514
22 M922@ M767
23 M050 W726
24 M890
25 M769
26 M763
27 G350
28 M765
29 G064
30 G062
31 G060
32 G050

@ = Cable
% = only at end of device bus; M903 cable otherwise
+ = Not required when used with a TM11 controller

Slave drives appear to hold a sub-set of this list; slots 6-15 are empty in Slave drives.

Note: In the TU10 Slave backplane drawings, slots 28-30 show different module numbers; however, those original module numbers are crossed out, and the same module numbers as in the Master drive are written in by hand (on the master copy). The captions in those slots (e.g. "Peak Detector"), however, match those of the written-in boards, not the boards originally listed. Thus, the original numbers may be erroneous.


The TU10W is actually a TU16 (effectively an upgraded TU10), with a board (M8926) (also used in the TE16) installed to make it useable with a TM11 series controller.