PLINK65.DOC

 PLINK is a CP/M transient command which allows the user to
communicate with a remote computer that is not running a special
program.  It allows the user to selectively copy received text
into memory and to later write the text onto a CP/M disk file.
It also allows text to be transmitted from a disk file to the
remote computer a line at a time, suppressing the line feeds and
waiting for a trigger character such as a line feed from the
remote computer before sending the next line of text.  Optionally
the trigger character may be a BELL code, an X-ON, or text may
be sent without pause including line feeds after the carriage
return.  Note that none of these options work for sending to a
DEC which uses an X-OFF, X-ON protocol when it gets more input than
it can handle.

 This program currently supports the following modems or computers
via conditional assembly:

1. PMMI modem
2. Any serial I/O board (TUART included)
3. TRS-80 model 1
4. TRS-80 model 2
5. Heath H8 with 8251 UART at port 330q
6. D.C. Hayes 80-103A or Micromodem 100
7. MITS 2SI/O board, ports 10h &11h = console, 12h & 13h = modem
8. Intel SBC or National BLC multi-bus boards using 8251 USART


Originally written by L.E. Hughes (EDCAM) in July, 1977.  Many
modifications have been made since this time, as shown in the
following summary.

Fixes/updates (in reverse order to minimize reading time):

June 26, 1981. Added message when exiting if last buffer was
not saved.  Ted Shapin.

June 14, 1981, by Keith Petersen, W8SDZ.  Changed port
equate to 'equ' instead of 'set'.  ASM doesn't like 'set'
when later conditionals are based on a label defined that
way.

June 7, 1981, by Tom Jorgenson (CP-MIG).  Changed CP/M 
origin from being via SETs to referenced to BASE, added
TRUE/FALSE rather than numeric values (for readability),
changed ^Q function to ^W (write) because some systems
(notably Micronet) use ^S/^Q to suspend/resume output,
changed page 0 references in TRS routines to use
BASE equate properly, changed PORT equates to default
to TRUE, reinserted Heath equates, and cleaned up code
in several places.

June 7, 1981, by Keith Petersen, W8SDZ.  Fixed problem with
equates which prevented assembly by 'ASM' when TUART option
was selected.

June 6, 1981, by Keith Petersen, W8SDZ.  Added version number,
cleaned up file.

May 12, 1981, by T. Shapin.  Added code for 8251 USART on Intel 
SBC or National BLC multibus board with modified CP/M origin.  
Added prompt to signon. Added toggle to ^Y to save or ignore 
incoming text. Added ^C abort on file name response.

(for earlier update info, see PLINK65.ASM).


PLINK currently supports two way transfer of text files between
the  CP/M disk and the remote computer.  The following control
codes may be initiated from the console keyboard:

Control-E      Exit PLINK to CP/M "warm-boot".

Control-T      Transmit ASCII file to remote system, asks for
               drive (A, B, etc.) and filename.typ.

Control-C      Aborts transmition of file to remote system.

Control-Y      Switches between saving and ignoring incoming
	       ASCII data in RAM buffer, for later transfer
	       to disk.

Control-Q      Writes RAM buffer to disk, and asks for drive
               and filename.typ.

Del (delete)   Backspace when in command mode (e.g. ^T or ^Q).

Control-U      Aborts current line when in command mode.

(Note: all other control codes are passed to modem output, and
may be interpreted by the remote system as various control
functions.)

When sending to another computer, PLINK waits for a trigger
response after sending each line before it will send the next.
The following "trigger" equate is set to "lf" (linefeed)
by default.  An optional trigger char may be passed via fcb1

 ie:  PLINK B		will set trigger to "bell"

The following options are allowed:

	1. B = bell  07h
	2. X = xon   11h
	3. U = upload no trigger check at all and send line feeds

any other ascii character may be passed through fcb1.

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