TS11, TSV05 — TS05 magnetic tape

The TS11 is DEC’s 1600 bpi magnetic tape subsystem for the UNIBUS, and the TSV05 the same programming model on the QBUS. A program sees two words of I/O page: it builds a command packet in memory, writes its address to the controller, and the controller fetches the packet, carries it out, and leaves a message packet with the outcome and the extended status in memory. QUniLator emulates the controller and one transport, a TS05, whose reel is a SIMH .tap image on the board. The controller is listed as ts, the transport as ts0.

It is the tape the bootstraps of the era know: an M9312 with the MS boot ROM boots from it, the MXV11-B2 set carries an MS entry for the TSV05, and it reads the tape kits of operating systems that came before TMSCP.

What the machine sees


Registers	TSBA when read and TSDB when written at the base address; TSSR at base + 2
Commands	Read (forward, reverse, reread), Write and Write Retry, Write Characteristics, Position (space records and tape marks, skip, rewind), Format (write tape mark, erase, retry), Control (message buffer release, rewind and unload, no-op, rewind with immediate interrupt), Get Status and Drive Initialize
Records	Up to 65,536 bytes
Transport	One TS05 at 1600 bpi. The end-of-tape marker lies `capacity` bytes down the tape, 40 MB for a 2400-foot reel. An erase lays down 3.75 inches of blank tape, which counts toward it
Rewind	Takes the time a real reel needs to wind back at 175 inches a second. With immediate interrupt the command answers at once and the tape reports motion until it reaches BOT
Boot	TSV05: a command pointer written with the boot bit set rewinds the tape, skips the first record and loads the first 512 bytes of the second into memory at 0

The subsystem carries one transport. A command that selects any other reports it off-line.

Write Subsystem Memory, which loads test functions into the controller’s microcode store, is refused as an illegal command.

Using it

Add ts on the Configurations screen, with its transport ts0.
Enable both. On the Dashboard, the tape widget’s ON LINE cap switches the transport on-line and off-line, and WRITE PROT takes the write ring off the reel and puts it back. READY lights while a reel is mounted and the transport is on-line; USE lights while the tape moves.
Set ts0’s image to a .tap file. Mounting loads the reel at BOT and puts the transport on-line.

A tape writes its image directly, and a program that writes tapes — a diagnostic among them — overwrites what is on it. To mount a tape that has to stay as it is, such as a distribution kit, halt the machine, clear writering, and then set image. A rewind and unload command from the machine — VMS’s DISMOUNT gives one — turns online off; press ON LINE, or mount a reel, to bring the transport back.

A reel can be changed while the machine runs. The change waits for the command in progress to finish, and the host meets the new reel as a volume check, the way it meets a reel an operator has changed.

A subsystem initialize rewinds the tape when the transport is on-line, as on a real TS11, so a program that initializes the controller starts again from BOT.

What has been verified

On the QBone’s TSV05, with Extended Features on, the XXDP diagnostics CVTSD (tests 1 to 4 and 6 to 9) and CVTSC (tests 1, 2 and 4 to 8) pass with no errors. The tests left out load test functions through Write Subsystem Memory.
CVTSE stops in TST 001 SUB 003. SimH’s TS11 stops there in the same way, so the diagnostic’s expectation is not met by either emulation.
On the UniBone’s emulated PDP-11/34, the M9312 MS boot ROM (23-764A9) boots the RSX-11M V4.2 distribution kit from the TS11.
A 2.11BSD kernel with the TS driver attaches the QBone’s TSV05 at boot as ts 0 csr 172520 vector 224.

Controller parameters

Settings

What a configuration stores and an operator sets.

Parameter	Short	Value	Default	What it is
`extfeatures`	`ef`	0 or 1, read-only on UNIBUS	1 on a 22-bit QBUS, 0 on the UNIBUS	Extended Features switch: 22-bit addressing and XST4

It also carries the parameters under parameters every card on the bus has.

In detail

`extfeatures`

The Extended Features switch of the TSV05’s M7196 module. On, command packets and data buffers are addressed with 22 bits, a write characteristics command takes its fifth word, the message packet carries XST4, and rewind with immediate interrupt is accepted. Off, the controller addresses 18 bits, as a TS11 does. It is read by every command, so a change takes effect with the next one. The UNIBUS TS11 has no such switch, and there it stays at 0.

Transport parameters

Settings

What a configuration stores and an operator sets.

Parameter	Short	Value	Default	What it is
`writering`	`wr`	0 or 1	1	Write-enable ring fitted; clear to write protect the reel
`online`	`onl`	0 or 1	1	Transport is on-line and accepts tape motion commands

Status

What the device reports as it runs. A configuration does not store these.

Parameter	Short	Value	What it is
`writeprotectlamp`	`wpl`	0 or 1	State of WRITE PROTECT lamp

It also carries the parameters under parameters every drive has.

On this device, capacity can be set.

In detail

`writering`

The write-enable ring in the back of the reel. Cleared, the reel is write protected: the controller refuses every write, tape mark and erase with the write lock error. Clear it before mounting a tape that has to stay as it is, such as a distribution kit; a program that writes tapes will otherwise overwrite it. A reel whose image cannot be written reads as one without a ring, whatever this says.

`online`

The transport’s ON-LINE switch. Tape motion reaches the transport only while it is on-line with a reel mounted; otherwise TSSR reports it off-line. Turning it off or on, like changing the reel, sets volume check, which the host meets with its next command. A rewind and unload command from the host turns it off; set it again, or mount a reel, to bring the tape back. Mounting a reel loads it and turns it on.

`writeprotectlamp`

The WRITE PROTECT lamp, lit while the reel is write locked: no reel, an image that cannot be written, or writering cleared.