#!/usr/bin/ruby
# encoding: utf-8

def help
puts <<HELPTEXT

"pc41 - the HP-41 <-> Linux connection"

Program created by Geir Isene (g@isene.com http://isene.com) to facilitate
connection between an HP-41 and a PC running  Linux/Unix/Mac OSX. It is used
with hardware connections such as the HP-41CL serial interface, the USB41
module and/or the PIL-box.

With this program and the USB41 module, you can use your PC as a printer for
the HP-41. USB41 module by Diego Diaz: http://www.clonix.org 

With this program and the serial interface to the HP-41CL replacement board,
you can transfer data/modules between a PC and an HP-41. HP-41CL by Monte
Dalrymple: http://www.systemyde.com

Starting with the output from "pc41 -h":

Usage: pc41 [options]  (no option = print to STDOUT from the USB41 module)
    -d, --dev DEVICE   Specify the device connected to the HP-41 (default=/dev/ttyUSB0)
    -r, --read FILE    Read from the HP-41CL serial interface and save as FILE
    -w, --write FILE   Write FILE to the HP-41CL serial interface
    -h                 Display SHORT help text
        --help         Display LONG help text

Make sure the program is "runable" (with "chmod a+x") and drop it in your "bin"
folder of choice and you are ready to go.

With the options "-r" and "-w", the program must be run as root to get access
to the serial/usb port. The program defaults to input from /dev/ttyUSB0, but
you may specify another input device by simply adding it as an argument to the
program:

    pc41 -d /dev/ttyUSB1

To use the program to transfer data/modules using the HP-41, you need to
provide one of two options:

    pc41 -r FILE
    pc41 -w FILE

With the option "-r FILE", you read data from the HP-41 and save to FILE.

With the option "-w FILE", you write data from FILE to the HP-41.

Default usage is with the USB41 module. Without the "-r", "-w" or "-c" options,
the program expects input from an HP-41 with the USB41 module and acts as a
printer.

Any printing from your HP-41 will go to Standard Out. To print whatever comes
from the HP-41 straight onto the screen, simply run the program:

    pc41

You can of course do all kinds of tricks on the PC side like piping the output
or redirect it to a file, etc.

To print a program on the HP-41 to the file "myprogram.txt" on the PC, do:

    pc41 > myprogram.txt

Instead of ending the program with a "Control-C" on the PC, you should
print the message "PREND" to flush out the remaining characters in the
print buffer and it will then terminate the program (just enter "PREND"
into Alpha and do XEQ"PRA").

You must have Ruby installed. To use the "-r" and "-w" options, you must have
"ruby-serialport" installed (on Ubuntu or Debian, do "sudo apt-get install
ruby-serialport"). Alternatively you may install ruby-serialport from RubyGems:

    sudo gem install ruby-serialport

For Mac OS/X users, the usual device would be "/dev/tty.usbserial ". 

To write the file "~/coolstuff.txt" from a Mac OSX computer to the HP-41CL
using the serial connector:

    pc41 -d /dev/tty.usbserial -w ~/coolstuff.txt        

Please amend the script if you want or ask me for new features.

Version: 0.5 (2013-12-12)
License: Public domain

HELPTEXT
end


# Load modules
begin
    require 'rubygems'
rescue
end

begin
    require "serialport"
rescue
    puts "You need to install ruby-serialport (gem install ruby-serialport)"
    exit
end

require 'optparse'


# Parameters for the serial port
$port_str = "/dev/ttyUSB0"
data_bits = 8
stop_bits = 1
parity = SerialPort::NONE


# Handle the command line options
options = {}

optparse = OptionParser.new do |opts|
    # Set a banner, displayed at the top of the help screen.
    opts.banner = "Usage: pc41 [options] (no option = print to STDOUT from the USB41 module)"

    # Define the options, and what they do
    opts.on('-d', '--dev DEVICE', 'Specify the device connected to the HP-41 (default=/dev/ttyUSB0)') do |dev|
	$port_str = dev
    end

    options[:read] = nil
    opts.on('-r', '--read FILE', 'Read from the HP-41CL serial interface and save as FILE') do |file|
	options[:read] = file
    end

    options[:write] = nil
    opts.on('-w', '--write FILE', 'Write FILE to the HP-41CL serial interface') do |file|
	options[:write] = file
    end

    opts.on('-h', 'Display SHORT help text') do
	puts opts
	exit
    end

    opts.on('--help', 'Display LONG help text') do
	help
	exit
    end
end

optparse.parse!


# Act on the options with the sequence below as precedence 

# Read data FROM the HP-41CL and save to file
if options[:read] 
    baud_rate = 9600
    sp = SerialPort.new($port_str, baud_rate, data_bits, stop_bits, parity)
    filename = options[:read]
    sp.read_timeout = 5000
    sp.flow_control = SerialPort::HARD # Important for handshake, etc.
    puts "Enter the address in Alpha on your HP-41CL (e.g. 80C000-0FFF for a 4K block at address 80C)."
    puts "XEQ\"BAUD96\" on the 41CL."
    puts "Press the Enter key on the PC and then XEQ\"YEXP\" on the 41CL within 5 seconds."
    STDIN.getc # Wait for user to press Enter
    puts "Commencing transfer from the HP-41CL after XEQ\"YEXP\" on the 41CL..."
    outdata = sp.read # The actual transfer FROM the HP-41CL
    if outdata == ""
	puts "No transfer"
	exit
    end
    filenametmp = filename + ".tmp"
    File.open(filenametmp, 'w') { |f| f.write(outdata) }
    # Perform byte swapping Big Endian/Little Endian by using "dd"
    %x[dd if=#{filenametmp} of=#{filename} conv=swab > /dev/null 2>&1]
    File.delete(filenametmp)
    puts "Transfer completed to to file named \"#{filename}\""
    sp.close
    puts "Connection closed."
    exit
end

# Read data from a file and send TO the HP-41CL
if options[:write] 
    baud_rate = 4800
    sp = SerialPort.new($port_str, baud_rate, data_bits, stop_bits, parity)
    filename = options[:write]
    filenametmp = filename + ".tmp"
    # Perform byte swapping Big Endian/Little Endian by using "dd"
    %x[dd if=#{filename} of=#{filenametmp} conv=swab > /dev/null 2>&1]
    indata = File.open(filenametmp, 'r') { |f| f.read }
    File.delete(filenametmp)
    sp.flow_control = SerialPort::HARD # Important for handshake, etc.
    puts "Enter the address in Alpha on your HP-41CL (e.g. 80C000-0FFF)."
    puts "XEQ\"BAUD48\" on the 41CL"
    puts "XEQ\"YIMP\" on the 41CL and press the Enter key on the PC within one second."
    STDIN.getc # Wait for user to press Enter
    puts "Transferring to the HP-41CL..."
    sp.write indata # The actual transfer TO the HP-41 CL
    puts "Transferred the file named \"#{filename}\" to the HP-41CL"
    puts "You should now see \"0\" in the display on the HP-41CL"
    sp.close
    puts "Connection closed."
    exit
end


# Act as a printer for the HP-41 with the USB41 module inserted
baud_rate = 115200
sp = SerialPort.new($port_str, baud_rate, data_bits, stop_bits, parity)
chrarray = ["♦", "¤", "ж", "←", "α", "β", "Γ", "↓", "Δ", "σ", 
    "♦", "λ", "μ", "д", "τ", "Φ", "Θ", "Ω", "δ", "Å", 
    "å", "Ä", "ä", "Ö", "ö", "Ü", "ü", "Æ", "æ", "≠", 
    "£", "▒", " ", "!", "\"", "\#", "$", "%", "&", "'", 
    "(", ")", "*", "+", ",", "-", ".", "/", "0", "1", 
    "2", "3", "4", "5", "6", "7", "8", "9", ":", ";", 
    "<", "=", ">", "?", "@", "A", "B", "C", "D", "E", 
    "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", 
    "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", 
    "Z", "[", "\\", "]", "↑", "_", "`", "a", "b", "c", 
    "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", 
    "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", 
    "x", "y", "z", "π", "|", "→", "Σ", "├"]
inchr = 0
outstr = ""

#loop do
#    inchr = sp.getc.unpack('C')[0]
#    puts inchr
#end

loop do
    inchr = sp.getc.unpack('C')[0]
    outstr += chrarray[inchr] if inchr < 128
    outstr +=" " * (inchr -160) if inchr > 160 and inchr < 184
    if inchr == 232
	outstr = " " * (24 - outstr.length) + outstr
	puts outstr
	outstr = ""
    end
    if inchr == 224 and outstr != ""
	puts outstr
	outstr = ""
    end
    if inchr == 240
	puts outstr
	break
    end
    break if outstr == "PREND"
end

sp.close
puts "Connection closed."
exit