ftp.whtech.com/ftp.whtech.com.tar/ftp.whtech.com/club100/cat/vt100.exe/lha/VTDOC3.DO

Text File | 1991-08-07 | 15KB | 301 lines

scroll and come to anticipate where the next characters will be,
reading the text will become much easier.  Remembering that a
horizontal scroll puts the next character in the middle of the
screen will help immensely in reading text as it is received.  At
300 baud, you should be able to read the text quite easily after
some experience with the scrolling method of 100/100.

It would be nice and smoother to be able to scroll horizontally
after each character past the fortieth column, but the slowness
of the LCD screen on the Model 100 makes such scrolling
impossible.

MOVING AROUND THE SCREEN

If you are having trouble reading the data as it is received, you
have three alternatives.  You can wait until the screen fills and
then go back and scroll through the screen at your leisure, you
can return to TELCOM and use its 40 column wrap feature, or you
can use the print screen function to get a hardcopy of the full
VT100 screen.  100/100 saves the full 80 column by 24 line screen
for later inspection or printing.  If the application doesn't
stop automatically on each screen, you may press CTRL S to stop
the display and then use the function keys F1 - F7 to move around
the screen and the PASTE key and CTRL Q to resume transmission
again.  The PASTE key exits view mode and returns to the screen
where the cursor is located.  If you used CTL S to stop
transmission of characters before entering view mode,  don't
forget CTL Q will resume transmission.

The screen as it would appear on a full sized VT100 is divided
into six sections.  (see FIGURE 1 in Section I)

  SECTION 1 -Lines 1-8, Columns 1-40
  SECTION 2 -Lines 9-16, Columns 1-40
  SECTION 3 -Lines 16-24, Columns 1-40
  SECTION 4-6 correspond to the lines in 1-3, but show the right
   half of the sreen, or columns 41-60.

The function keys then move the current screen to any of these
six sections.  Pressing F1 -F3 show sections 1-3.  F4 will move
down 4 lines, allowing you to view the bottom half of one section
with the top half of the section below.
F5 will always display the left 40 columns, in whatever the
present vertical position happens to be.
F6 will always display the middle 40 columns (columns 21-60),
again in the current vertical position.  This section overlaps
half of each of the left and right sections
F7 will always display the right-most 40 columns (41-80) in the
current vertical position.
PASTE will return you to wherever the cursor is presently located
and exit view mode so you can continue.  PASTE also exits "fast
mode" as explained below.

After any of the function keys through F7 have been pressed, no
further characters can be received from the host.  The cursor is
displayed in the lower right corner of the screen to remind you
that you are in view mode.  Pressing PASTE returns the cursor to
the proper position, as well as to the current screen where the
cursor is located and allows the program to resume.

As an example, imagine an application which paints the screen
with some header information at the top, and then two columns of
information down each half of an 80 column screen, then returns
to the top of the screen to wait for input from the user.
Columns of information can be especially difficult to read as
they transmit, since the blank spaces often make it difficult to
distinguish between scrolls to the left from the  right.  In this
example, after the screen has been filled and the cursor returns
to the top portion of the VT100 screen, 100/100 would jump from
displaying the bottom sections 3 or 6 back to the top section 1
or 2.  Assume you are in section one at the top left of the
screen.  Pressing F1 would have no effect on screen movement,
since you are there already.  However, the cursor would move to
the lower right corner to remind you that you are in view mode,
and not accepting characters from the host.

Pressing F6 would scroll you over 40 characters, and F7 would
show you the last 40 columns of the top 8 rows.  Pressing F5
again, would return you to the top left screen again where you
started.  Pressing F4 will allow you to move down, reading the
first column of information.  F4 again, will move down another
four rows.  F4 another four rows, and so on, until you reach row
24

Pressing F7 at this point would move you to the lower right
section of the screen, lines 17-24, columns 41-80.

If you now want to scroll down the right half of the screen and
read the second column, you would press F1, to bring you to the
top, F7 to bring you to the right half, then  F4 to scroll down
four lines.  Just as on the left side, pressing F4 will scroll
you down four rows at a time until you reach line 24.  Get the
idea?.  When through looking at the screen, PASTE returns you to
where you started and exits view mode so character transmission
to and from the host can resume.

In summary, F1 - F3 are absolute moves, going to sections 1-3 on
the left side of the screen.  F5 - F7 are somewhat relative,
always displaying the left, middle and right section
respectively, but relative to the current vertical position.  F4
is a pure relative move, always moving down four lines from
whatever the current position is.  The seven function keys allow
very flexible movement over any portion of the 80 x 24 screen.

MOVING BETWEEN 100/100 AND TELCOM

Even with such flexibility of movement, pure text files are often
much easier to read in regular TELCOM mode, where they
automatically wrap at column forty.  Reading mail and the like
where characters just come sequentially, one after another, is
sometimes much better in TELCOM mode.  Pressing F8 will return
you to that mode at any time.  Pressing F6 in TELCOM will put you
back into VT100.  You can toggle back and forth as often as you
like.

Be aware that if you exit 100/100 back to TELCOM and then
re-enter 100/100, the screen will clear and the default VT100
settings will be restored.  If you exit 100/100 while in an
application that has changed some of the parameters at startup,
such as tab stops or the scrolling region and then re-enter the
emulator while in the same application, the application specific
settings will have been lost and the default settings restored.

100/100 was written because many applications, are screen
oriented and require VT100 compatiblity.  Where screens are
displayed and you fill in blanks, do word processing, edit or run
other similar applications, these cannot be done in TELCOM mode.
This is where the VT100 emulator, and its ability in view mode to
move around the various screen sections at will is invaluable.

Many applications which use direct cursor addressing, jump quite
erratically from top to bottom and from side to side on the
screen.  On a real VT100, only the cursor is moving.  In 100/100,
different screen sections are displayed to match the current
cursor position.  Often it is hard to sort out just what is being
displayed until all the action stops.  Many times, the screen
looks jumbled due to the way it jumps around.

For example, a word processing/editing application may use the
cursor to move down each line, but start scrolling the screen up
after line 15 so the cursor remains in the middle oI
the screen and not at the bottom.  On a VT100, when you reach
line fifteen, the cursor will jump to the bottom (line 24) of the
screen, and a line feed will create a blank line at line 24 and
the rest of the screen will scroll up.  The cursor will then
return to line 15, where it was.  On a real VT100, all you really
see is the screen scrolling up one line.  In 100/100 however,
when you reach line 15, lines 8-15 will be showing on your
screen, since that is your virtual window into the larger VT100
screen.  When the cursor jumps to line 24 to perform the line
feed, your screen window will jump to lines 17-24 where  the new
line will appear.  When the cursor returns to line 15, your
window will jump back to the original window.  As you can see,
with a lot of cursor movement, your window could be jumping
around a lot.

Pressing the LABEL function key at any time will show you where
the cursor is presently located, relative to  a 80 x 24 screen.
After pressing LABEL, the row and column will be displayed in the
lower left corner of the screen.  If this display covers up
something you want to see, PASTE will repaint the screen with the
correct information, otherwise it will automatically clear as
soon as the screen needs to scroll either vertically or
horizontally.

As mentioned above, if at any time you wish to enter TELCOM,
either to view text in 40 column mode, or to use the ECHO to
printer, UPLOAD and DOWNLOAD features of TELCOM, pressing F8
exits 100/100 and enters TELCOM.  The screen is not cleared, so
if you had a prompt awaiting action, that prompt will remain.  If
you wish to exit and clear the screen, pressing CODE 'e' will
exit just as F8, but the screen will be clear upon entering
TELCOM.

FAST MODE

If you are using 100/100 with the built-in modem at 300 baud, the
screen can keep up with characters transmitted from the host.
However, if you are using an external modem at 1200 or 2400 baud,
or a direct connection, the constant screen scrolling and the
slowness of the LCD screen keep the actual speed around 400 baud.

FAST MODE was created to allow you to take advantage of the
higher speeds and cut down on connection costs.  Pressing GRAPH
'f' enters this mode.  In FAST MODE, the characters are not
echoed to the screen.  Rather, the column/row display is
constantly shown in the lower left corner of the screen and only
the cursor continues to move across the display.  At speeds of
1200 baud or greater, the cursor moves very fast and the
column/row is updated every 20 characters to give you an idea of
where you are at in filling the screen.  The cursor movement is
very erratic and simply shows that characters are still being
transmitted by the host.  The moving cursor may even leave some
garbage on the screen.  This is normal and it will disappear as
you exit Fast Mode.  Fast Mode is best used with applications
which fill an entire screen and then stop before proceeding to
the next screen - like menu applications.  When the cursor
movement stops, pressing PASTE will exit fast mode and allow you
to see the characters which have been received.  You will be at
the current cursor position.  F1 - F7 can then be used to move
around the screen.

You can press GRAPH 'f', then PASTE if you need to see check
what's coming in, then GRAPH 'f' again.  PASTE does not stop
transmission, it just turns on the echo of the characters and
scrolling.

If you exit VT100 mode back to TELCOM while in Fast Mode, and
then re-enter VT100 mode, you will find yourself still with no
echo and must press PASTE.  Fast mode can always be recognized by
the column/row display and the cursor movement.

FAST DOWNLOADING

Pressing CODE 'd' activates a feature to speed downloading of
files.  Since downloading always means capturing the characters
as they come on the screen, and since the Model 100 screen tops
out at about 600 baud when it has to scroll, files could never be
downloaded faster than that rate.

Pressing CODE 'd' while in VT100 mode will enter the TELCOM
download routine and lock the screen scroll so files may be
downloaded at the speed you are running, whether it is 1200 or
2400 baud.  The result is lower telephone toll charges or smaller
fees from on-line services.

F7 in TELCOM is then temporarily redefined during the download to
act like the F2 key to stop downloading and also reenter VT100
mode (and unlock the screen), so when you have finished
downloading the file, press F7 instead of F2 and the file will be
closed, scroll will be enabled again, and you will be in VT100
mode once more.  However, the screen will be cleared since the no
scroll mode will have most likely left garbage on the screen.

During the downloading, you are actually in TELCOM, not VT100.
Pressing F7 returns to VT100 mode.  Unlike leaving VT100 mode by
pressing the F8 key, this method retains any application specific
settings your host computer has set.  For example, if top and
bottom margins have been changed so the application has a message
line at the bottom of the screen, these margins will be
preserved.  In addition, tabs, new line mode, and wrap mode are
all preserved.  Contrast this with exiting VT100 mode by pressing
F8 and returning by pressing F6.  The top and bottom margins and
other settings would be restored to their original defaults as
they come with the program, or to the ones you have set using the
SETUP.BA program.

In summary, to use the fast downloading feature:

  1.  Press CODE d
  2.  Answer the prompt 'File to Download?'
  3.  To stop downloading and reenter VT100 mode press F7

If a download aborts before you press the F7 key, either because
available memory was filled, you typed in an invalid filename, or
out of habit you accidentally used the F2 key to stop
downloading, then you must take an extra step before returning to
VT100 mode if you want to save your settings.  First press F2 to
start the download again and if the abort was due to mistyping
the filename, type in the correct name and then you can download
as before, turning off the download with the F7 key.

If, however, the abort was due to lack of memory, you cannot
continue to download..  If you accidentally used the F2 key to
stop downloading, you may not want to download again.  In these
cases, press F2 as if you were going to download once more.  Type
in a filename of a non-existent file at the prompt.  Then
immediately press F7.  You will have created an empty file and
returned to VT100 mode with all your settings unchanged.  (If you
type in the name of an existing file, you will empty that file)

Of course, if you don't care if you reset VT100 mode to the
default settings, then after the original abort, just press F7
and ENTER to reset F7 then F6 to enter VT100 mode.

If you want to download multiple files before returning to VT100
mode, then terminate the first download with F2, as you normally
would in TELCOM.  Then press F2 to begin the next download.  The
screen scroll will remain locked.  You can continue to download
as many files as you have memory for, using the F2 key, but the
last download should be terminated with the F7 key.

If you wish to download from VT100 without locking the screen
scroll, then simply press F8 while in VT100 to enter TELCOM and
use the F2 key to begin and to end the process as you normally
would during a download.  When finished, press F6 to return to
VT100 mode.

PRINTING THE SCREEN

The PRINT function key can be used to get a hardcopy of the full
VT100-sized screen at any time.  You must use CTL S to stop
character transmission from the host if there is no natural
break.  Press the PRINT key and the printer should immediately
begin to print the full 80 column by 24 line screen.  If the
printer is turned off or not connected, no action is taken.  Only
parallel printers are supported with this feature, since the
Model 100 cannot support a serial printer on the RS232 port and
the modem simultaneously.