TU10 magtape drive
|Tape speed:|| 45 ips (Forward/Reverse)|
150 ips (Rewind)
|Size:||19"W x 26"D x 26"H|
The TU10 is a classic big magnetic tape drive from Digital Equipment Corporation, able to store 5-20 Mbytes on a 2400' 0.5" wide magnetic 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, with a TM10 controller; 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 there.
The TM11 controller connects to a 'Master' TU10 drive, which includes extra Flip Chip modules in its 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.
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.
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 used by the controller to the negative bus. This is the pinout of the negative bus:
This table shows the number of Flip Chips of each type in the electronics backplane of the Master and Slave TU10's:
|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|
|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|
|M891||1||CRC and Write Gating|
|M892||1||Write and Gap Timing|
|M958||1||Positive Bus Terminator|
This table shows the Flip Chip modules locations in the integral backplane. (Dual-height cards, which most of the TU10 cards are, are shown as taking the entire slot. Single-height cards are show in correct 'side' of the slot.)
Slave drives appear to hold a sub-set of this list, slots 6-15 are empty in Slave drives; cards present only in Master drives are in italics:
# = Cable
$ = Cable plugged into the bottom half of this dual card
& = Cable, but only when more than one drive
% = Only at end of device bus, M903 cable otherwise; with a single drive system, may be in either slot
+ = Not required when used with a TM11 controller
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 of the drawings). 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 are likely erroneous.
- EK-TU10-MM-007 TU10 DECmagtape maintenance manual
- DEC-00-TU10M-D TU10 DECmagtape Master System Manual - covers the master functional unit in drives configured with it