iting. The high
speed channel is given the memory location of the information, and the
number of registers the words read or written will occupy. The channel
effects the information transfer. Thus, a high speed channel connected
to a tape control handles the programming for the unit word transfers.

Completion of the block transfer is signified by either setting a
program flag, or entering the sequence break.

_Connection with Sequence Break System_

When the TC is connected to the Sequence Break System, the program is
automatically interrupted each time an MPS command needs to be given.

Programming is unaffected during reading and a record may be read with
no flags set. The TC initiates breaks so that an MPS may be given in
time.

Similarly, the break is initiated during writing each time an MPS needs
to be given.

_Motion Command Summary_

_Time before _Time between _Time after End of _Flags that
first MPS_ MPS's_ Record to deselect_ may be set_

MWA 3 ms. 400 us. 10 ms. RWF (if unit
MWB (longer time is deselected
causes deselection) and MPS given,
or unit becomes
unavailable),
Parity, EOT.

MRA 7 ms. < 400 us. 5 ms. RWF, (if
MRB (longer time information
misses information, is missed, or
and unit becomes
rwc set) unavailable),
EOT, EOR,
Parity.

MBA - - 10 ms. RWF (if unit
MBB becomes
unavailable),
EOR, EOT.

CATHODE-RAY-TUBE DISPLAY

The PDP-3 Cathode Ray Tube Display is useful for presentation of
graphical or tabular information to the operator. It uses a 16 inch
round tube with magnetic deflection. For each In-Out transfer order, one
point is displayed at