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C REC  PAGE   DESCRIPTION
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C00002 00002	IMLAC USER'S MANUAL					  30 Sep 1973
C00007 00003	SPECIAL FUNCTION KEYS
C00009 00004	LINE MODE
C00012 00005	LOCAL CONTROL FUNCTIONS
C00014 00006	TROUBLE-SHOOTING PROCEDURES
C00017 00007	RELOADING
C00020 ENDMK
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IMLAC USER'S MANUAL					  30 Sep 1973

by Bo Eross


INTRODUCTION AND CAVEAT

This document describes  the program which  is resident in  our IMLAC
terminals.   The program is  an attempt to simulate  (locally, on the
IMLAC) as many as possible of  the features of the Data Disc  display
system.  I will assume for the  purposes of this writeup that you are
familiar  with the  use  of the  DD consoles.   You  may occasionally
notice your  output being  garbaged.   The  two main  causes of  this
problem  are the  unreliability of  the telephone  line which  is the
only link between the IMLAC and the PDP-10, and heavy system  loading
on the  10 preventing it  from servicing the  incoming line  in time.
Sorry  about that.    Sections of  this writeup  marked  *** describe
features that  are present  on the  IMLAC but  not yet  known to  the
PDP-10.   I shall  put these features  into the system  as soon  as I
can.


GENERAL DESCRIPTION

The IMLAC operates  in two distinct  modes: Character and Line.   The
top line of the  screen displays "*C*" or "*L*" to show which mode is
in effect.  In  Character mode, the  keyboard is coupled directly  to
the phone  line and the  IMLAC acts more  or less like  a full-duplex
teletype.  In Line mode, the keyboard is  connected to the local line
editor.  Your typein stays  in the IMLAC until you hit  an activation
character, so  that you can  backspace, insert, delete,  and overtype
exactly as you would  on a DD  console.  When  you hit an  activator,
the part of the edit  line to the left of the  cursor disappears from
the screen  and shoots over the phone line.   The 10 reads and echoes
your data as it  would a TTY, and the  line reappears when the  IMLAC
receives the echo.

The  CALL, ESC,  BREAK,  and  CLEAR keys  are  in  effect a  separate
keyboard.   These  keys  provide  special   functions  that  are  not
logically part of either mode of operation.

The IMLAC's display routine  includes a timer that turns  the display
screen off  after about  10 minutes of  inactivity.  The  screen will
come back on  whenever the IMLAC  receives an input  from either  the
keyboard or the phone line.

The IMLAC's memory  has enough room  to hold about 1K  characters for
displaying.   This  is enough  for 15  to 20  full-width lines  or an
entire page of  short lines.  The  program tries to  keep as much  on
the screen as it  can, and deletes the top line only  if there is not
one character space left in memory.

*** The program has some built-in provisions to  allow the use of the
SOS editor's  Z and Q commands, and DDT  (word mode) input.  However,
the system on the 10 doesn't know  about these yet.  So for the  time
being, use character mode to talk to DDT and to SOS's A command.
SPECIAL FUNCTION KEYS

[CALL]	Sends ↑C↑C.  If in line mode, clears the edit line.

<CONTROL>[CALL] is the same as [CALL], but sends only one ↑C.

[ESC]<letter> sends  ↑<letter> without affecting  the edit  line. For
	example,  [ESC]C  is the same as <CONTROL>[CALL]  but doesn't
	clear the edit line.

<CONTROL>[ESC] is the prefix for local  control functions that affect
	only the IMLAC.

[BREAK] does nothing.  This is the recommended  key to use for waking
	the IMLAC up when its screen is timed out.

<CONTROL>[BREAK] holds  typeout and  displays the legend  "*HOLDING*"
	at the top of the screen.

[CLEAR] in Character mode,  sends ↑U (delete current line).   In Line
	mode, clears the edit line.

<CONTROL>[CLEAR] releases the  typeout if it is holding,  and removes
	the "*HOLDING*" message.







CHARACTER MODE

In Character mode,  everything you type  is sent exactly as  you type
it.  *** If you  type a character  with the <CONTROL>  or <META> keys
held down, the  control bits are  sent as a  prefix character.   Note
that <CONTROL>C, for  example, is NOT the same thing  as ↑C or [ESC]C
or <CONTROL>[CALL].
LINE MODE

This mode contains  all of the  editing functions that  are available
on DD consoles, plus a few that are peculiar to the IMLAC.

STANDARD DD FUNCTIONS:

<CTL>[SPACE]	Move right	|<CTL>S<char>	Skip to <char>
<CTL>[BS]	Move left	|<CTL>[TAB]	Skip to end
<CTL>D		Delete right	|<CTL>[FORM]	Skip to beginning
<META>[BS]	Delete left	|<CTL>K<char>	Kill to <char>
[BS]		Delete at end	|<META><char>	Insert <char>
[CLEAR]		Clear line	|<CTL>I		Enter insert mode
<any char>	Overtype	|<any command>	Leave insert mode
<CTL>[RET]	Retrieve line	|<CTL><number>	Repeat command


ADDITIONAL FUNCTIONS:

<CTL>[ALT]		Retrieve line and leave cursor at end
<CTL><META><char>	Send <char> without affecting the edit line
<CTL>T			Send the part of the line which is left of
			the cursor

Insert mode (<CTL>I) changes the shape of the cursor.

The <CTL>S and <CTL>K  commands do not distinguish between  upper and
lower case letters.

***<CTL><META>[LF]  appends  the   correct  code  to  the   line  and
activates,  but the  10  doesn't recognize  this function  yet.   Use
[ESC]Z instead.


ACTIVATION CHARACTERS

In Insert  mode, the IMLAC  ignores the activation  characters [RET],
[LF], and [ALT]  unless they have a control bit on.  <CTL><activator>
means leave insert mode, move  to the end, append the activator,  and
send.    <META><activator> means  insert  the  activator here,  leave
insert mode, and send the part that's left of the cursor.
LOCAL CONTROL FUNCTIONS

These commands  affect only the  IMLAC.  They  are all  prefixed with
<CTL>[ESC]

A	Automatic hold.  Flags  the bottom line of the  screen.  When
	that line is about to be deleted, the  output will hold as if
	you had  typed <CTL>[BREAK].   At this  time, the new  bottom
	line is flagged.

M	Manual hold.  Undoes <CTL>[ESC]A.

C	Enter Character  mode.  If  the edit line  is not  empty, its
	contents will be sent.

L	Enter Line mode.

S	Slow send.   Line mode  transmissions happen  at half of  the
	maximum speed.  This is the default mode if the IMLAC.

F	Fast send.  Line mode transmissions happen  at full speed. If
	the 10 is heavily  loaded, it probably won't be  able to keep
	up and your inputs will be garbaged.

W	Wait.   Turns  the  screen  off as  if  it had  exceeded  its
	10-minute inactivity time.

I	Initialize.  Clears  the screen and  resets the IMLAC  to its
	default conditions.

B	Bootstrap.   Jumps  to  the  hardware bootstrap  loader  (see
	reloading procedure)

Z	Buzz.   Repeatedly  sends  the contents  of  the line  buffer
	until you hit any key.  A hardware maintenance aid.
TROUBLE-SHOOTING PROCEDURES

The controls  are at the  back of the  lower cabinet, just  below the
table  top.  Left and  right are in  terms of facing  the screen from
the front.

The power switch  is the large circuit  breaker at the  left.  On  is
up.

The startup  box is  at the  right.  This  box has  three pushbuttons
labeled "start",   "at 40", and "stop", and a small red light labeled
"run".

If the IMLAC appears to be dead:

1.	Make sure  that the power  cord is plugged  in and  the power
	switch is on.

2.	If the "run" light  is off, press "start".  If  the run light
	doesn't stay on, you'll have to reload (see below).

3.	If the  run light  is on  and the  screen is  blank, hit  the
	[BREAK] key.   If  the screen  stays blank,   you'll have  to
	reload.

4.	Type <CTL><ESC>I.  The IMLAC should oblige  you with a nearly
	blank screen with *L* showing at the top.   Then type any old
	thing. You should see  what you typed showing on  the screen.
	If none of these happen, you have to reload.

5.	Type [CALL] a few times.  If you  get no response, the PDP-10
	is down or the phone line is dead.   There's nothing more you
	can do.

6.	If you  got this far,   everything is  happy.  If  you're not
	convinced of that, go ahead and reload.
RELOADING

A. If the IMLAC is alive and the 10 is responding:

	1. Type the monitor command FIX.

	2. When the FIXIML program responds with a *, type
	   <CTL>[ESC] B and <CTL><TOP><SHIFT>S.

	3. Sit back and relax.  After a few seconds, the IMLAC's
	   screen will show some large, rapidly changing numbers.
	   It's displaying the current address in IMLAC memory
	   where it is loading.  When the loader is done the screen
	   will go to normal state, pause for a few seconds, and
	   tell you "CHECKSUM OK".  If instead it says "CHECKSUM
	   FAILED" there may be trouble.  Reload again if you don't
	   want to take a chance.


B.  If the IMLAC is dead:

	1. It will be helpful to know whether the 10 is up.  You
	   can't reload if it isn't.

	2. Make sure that the power is on.

	3. Push "stop".  Then hold the "at 40" button in and push
	   "start".  The "run" light should come on and stay.  If it
	   doesn't, there are problems with the hardware.  Sorry.

	4. Put "shift lock" off (up).

	5. Type <SHIFT>C a half dozen times.  This sends ↑C's to the 10.

	6. Type this EXACTLY AS SHOWN: fixM
	   The 10 sees <SHIFT>M as a [RETURN].  If you goof, go back
	   to step 4.

	7. Wait about 10 seconds to give the system time to log you in
	   and start FIXIML running.

	8. Type <CTL><TOP><SHIFT>S
	   This strange code tells the IMLAC's hardware loader to go.

	9. Go to step A.3 above.  If nothing shows on the screen after
	   a minute, you lost somehow.  Try the whole thing again.