PCShare Help Contents

Welcome to PC-Share for MS-DOS on-line 
help. All help within PC-Share is organised 
in this manner. Text pertaining to a 
particular topic is listed in the main help 
window as per this text. Any help text 
which does not fit into a single window can 
be scrolled using the PgUp, PdDn keys. 
Topics of reference or further interested 
are listed in the popup menu to the right 
of this window. To vist one of these topics 
press the F2 key, then using the mouse or 
arrow keys select the required topic. A 
single mouse click, or press of the ENTER 
key will make the selections. Press F1 at 
any time to return here. 

As an example, the following topics of 
interest are selectable from here:

Overview


Version 3.1 Features


PC-Share Product Range

Development Kit

Commands

Procedures
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PC-Share Overview

PC-Share is a package of utilities designed 
to allow another computer system to utilise 
the peripherals and operating system of a 
PC for it's own use. This is accomplished 
through a single hardware port by means of 
a predefined message protocol. Device 
drivers and file managers written for the 
host computer intended to interact with PC-
Share are normally used to implement this 
protocol thus providing a transparent 
interface layer between host computer 
and PC. 

PC-Share is available ready to run for use 
with an Intel 8255 PIO chip or the standard 
LPT parallel port and development 
kits are available for 

producing versions with an alternative 
hardware interface. 

When first started, the title screen is 
displayed followed by a clear screen and 
the word 'Ready.' displayed. The system is 
now ready to communicate with the host 
computer. Textual and graphical data sent 
to the PC is displayed on screen, whilst 
keypresses entered into the PC's keyboard 
is sent to the host machine for processing.

PC-Share's main menu is 

activated by pressing the Alt-F10 keys. 
From this menu system settings and 
configurations may be entered or altered. 
The menu also provides a number of 
utilities such as Copy/Paste and File 
Import/Export functions.

PC-Share product range and host computer 
support
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Product Range & Support

The following PC-Share applications and 
support is available:


PCShare V3.1 for MS-DOS.

PCShare for DOS will run on any 80x86 based 
PC under MS-DOS V3 or greater.It gives host 
computer access to screen, shared hard 
disk, VGA graphics, MS-DOS file transfer, 
COM and LPT port usage and access to the 
Real Time Clock (RTC). 

PCShare V3.1 for Windows 3.1, 95 and NT

PCShare for Windows will run on any 80286 
or better PC running Windows 3.1, 3.11, 
Windows '95 or Windows NT. It offers all 
the capabilities of the DOS version plus 
the ability to launch multiple display 
windows for multi-tasking host computer 
OS's, full Windows clipboard access both 
through Copy/Paste and direct file transfer 
along with full configurable PC-keyboard.


Development kit

Available for both DOS and Windows 
releases, allows a new PCShare application 
to be built utilising a different hardware 
interface. 

OS9 File Manager and Device Driver Support

A full driver set is available for OS9 
Level 1 utilising the Motorola 6821 PIA 
chip. Source code for the relevent OS9 
drivers is also available for alternative 
hardware and other platform development.

Host Computer Driver Development

The full interface document (necessary for 
driver development) is available from my 
website, along with supporting 
documentation and a full user manual to 
assist in device driver development for any 
computer platform. Downloading of the OS9 
driver source may be useful as a reference 
point. 

The PC-Share project is an ongoing venture. 
For access to support documentation and the 
latest upgrades and releases contact:

http://www.jons-pc.demon.co.uk/pcshare1.htm

or email to

 jrb@jons-pc.demon.co.uk

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Development Kit

The PC-Share development kits allows a new 
PC-Share application to be built utilising 
a different hardware architecture. In order 
to use the development kit you must have 
access to a Borland C compiler V3.0 or 
better.

The process of creating a new hardware 
interface involves writing a C module 
capable of performing byte wide IO to your 
designated interface and linking it with 
the rest of the PCShare package shipped as 
a C library file. To this end the 
development kit includes source code to the 
Intel 8255 PIO driver and details on how to 
go about writing the new driver.

Full details of obtaining and using the 
development kit are available at: 

http://www.jons-pc.demon.co.uk/pcshare1.htm
@@
PC-Share for DOS v3.1

PC-Share for DOS provides the following 
functionality for a host computer:

Shared Hard Disk:

The host computer can store files in it's 
own format onto the PC's hard disk.

MS-DOS File Access:

The host computer can read and write MS-DOS 
format files. It can also access all 
attached DOS devices (LPT1, COM1 etc.)

Text and Graphics

The host computer can display text and 
perform graphics operations on the PC's 
monitor.

Terminal Emulation:

PC-Share supports two terminal emulators - 
DEC VT100 and Dragon/OS9 GO51 which can be 
selected by the host computer.

Keyboard Mapping:

The protocol allows the use of the PC's 
keyboard with the host computer with re-
programmable keyboard layout. Alternativly, 
the host's own keyboard may be used if 
preferred.

Real Time Clock:
The PC's Real Time Clock(RTC) can be read 
by the host computer.

Command Shell Forking:

The host computer can fork a DOS command 
shell from it's own operating system.

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PC-Share Main Menu

The Main Menu (activated by pressing Alt-
F10) provides the facilities for 
configuring and setting up the systemwide 
default options for PC-Share.

The Main Menu provides the following 
options:

File - controls MS-DOS file 

export/import and capture from the host..

Edit - provides copy and paste 

functions for the host machine.

Config - Setup for hardware 

port, system colours and fonts etc.

Help - activates this help dialog.

Quit - Exits the program.
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Config Menu

The Config Menu provides options for 
configuring the system hardware, setting 
default screen colours and setting up the 
PC's keyboard for use with the host 
computer:

Settings - sets the hardware 

characteristics of PC-Share.

Keyboard Map - defines the 

default mapping of the PC's keyboard for 
the host computer.

Colours - sets the default 

display foreground and background colours.

Save Config - saves current system settings 
to disk. These are written to the PCShare 
configuration file PCSHARE3.CFG in your PC-
Share directory. Next time the application 
is stared, these settings will be used.
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Settings Menu

The Settings Menu is obtained by selecting 
`Settings' from the Config Menu on the PC-
Share Main menu. When invoked, the settings 
dialog box is displayed:

The first item in the dialog box configures 
the PC-Share hardware.

Enter into the IO Port Base box the 
hardware address of the parallel port 
connecting to the host computer.

The next two items configure the host 
computer's hard disk(s) to be 

implemented by PC-Share.

Enter into the Hard Disks box the number of 
hard disks to be supported by PC-Share. Up 
to 10 hard disks for the host computer may 
be implemented.

Enter into the HD Sector Size box the size 
of a disk sector expected by the host 
computer.

The PCShare Directory box 

contains the path where the applications 
stores it's working files.

The Terminal Emulation 

opens up a menu to select which default 
terminal emulation you required - DEC 
VT100, OS9/GO51 or None.

Clicking on OK saves the entered 
information into PC-Share's configuration 
file. Clicking on Cancel discards the 
changes made.

Normally these settings are entered when 
the PC-Share package is first setup and 
will not require changing during normal 
operation.
@@
Hardware Settings

PC-Share's hardware settings primarily 
consist of setting the IO Port Base 
address. This defines where in the PC's 
address map PC-Share can find the parallel 
port you have connected your host computer 
to. Typically, the physical hardware 
address is set via jumpers or dip switches 
on your IO card. 

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Pseudo Hard Disk

PC-Share provides the ability to store data 
on a PC's hard drive in a host computer's 
native format. This `pseudo' hard disk is 
implemented by the host computer passed 
it's track/sector information direct to PC-
Share which then translates the information 
into a position within an MS-DOS file. Up 
to 10 of these hard disks may be supported 
by PC-Share, however the actual number 
implemented at any one time is defined by 
the `Hard Disks' count in the Settings 
dialog box. Each hard disk file is held in 
your PC-Share working directory 

as HDISKn.BIN where n is the disk 
identifier from 0 to 9.

PC-Share also needs to know the size of a 
disk sector on the disk - consult the host 
computer's documentation for this 
information - as an example PC's use 512 
bytes/sector where as the OS9 system 
utilises 256 bytes/sector.

In order to configure the hard disk on the 
host computer, you will normally be 
required to enter the size of the disk in 
terms of  Number of Tracks and Sectors Per 
Track. The device driver for your host 
computer must then translate this 
information into Logical Sector Numbers 
(LSNs) to be passed to PC-Share. An LSN is 
calculated as follows:

  LSN = Track No. * Sectors Per Track + 
Sector Number - 1

This assumes Track numbers start from 0 and 
Sector Numbers from 1. The host computer 
must provide this translation from it's 
track & sector information.

PC-Share does not have any knowledge of 
Track/Sector information. When entering 
configuration information into your host 
computer, you should just ensure that the 
total space you require is met.

As an example, for a 512 byte/sector, 40MB 
hard drive you could enter:

Total Tracks: 320
Sectors/Track: 256
Bytes/Sector: 512 

320 * 256 * 512 = 40MB

or

Total Tracks: 160
Sectors/Track: 512
Bytes/Sector: 512

160 * 512 * 512 = 40MB

or any combination allowable by your host 
computer.

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Configuration Directory

PC-Share's configuration directory as 
entered through the Settings 
Menu defines where it can 

locate all the working files. Typically 
this is the same place as the PC-Share 
executable. 

PC-Share stores it's configuration file 
(PCSHARE3.CFG) in this directory, which 
holds:

The Hardware Port IO 
Address
Pseudo Hard Disk Information
Default Terminal 
Emulation
Default Screen Colours
Default Keyboard Mappings

The Pseudo Hard Disks named HDISK0.BIN 
through to HDISK9.BIN are also held in this 
directory.
@@
Terminal Emulation

Traditionally, computer's may be attached 
to a video terminal of which they had no 
direct control of the terminal's hardware - 
often termed a `dumb' terminal setup. In 
order to control the display of these 
terminals, the host computer would issue a 
set control characters, typically referred 
to as `escape sequences' to perform cursor 
positioning, text highlighting etc.

PC-Share offers two in-built terminal 
emulators which process these escape 
sequences for the PC's screen.

DEC VT100 implements a sub-set of the most 
widely used emulation sequences implemented 
by many commercial terminals.

Dragon/OS9 GO51 implements the sequences 
used to control the screen display when in 
GO51 video mode under OS9 Level 1 on the 
Dragon 64 computer.

All terminal emulation, apart from basic 
operations (like Carriage Return, Line Feed 
etc.) may be disabled if required by 
selecting `None' from the option list.

The Default Terminal Emulation may be set 
on the Settings Menu, this determines the 
emulation used whenever the package is 
first executed.

The emulation used may also be changed by 
the host computer, however this only takes 
effect for the current session unless the 
'Save Config' option of the Config menu is 
used to save the changes.
@@
Screen Colours

Screen colours (the background and text 
colour) can be configured from PC-Share in 
two ways:

Through the Colours Menu of the Config 
Menu. When selected, a sub-menu is 
displayed for Foreground or Background 
colour. Either will display a further menu 
listing the colour choices with the current 
setting highlighted. Any colours entered 
remain for the current session only unless 
the Save Config option of the Config Menu 
is used, in which case they will be used as 
the default for the next session.

The host computer may also change the 
foreground and background colours, these 
changes can also be saved as the defaults 
in an identical fashion.
@@
Keyboard Maps

The PC's keyboard may be used with PC-
Share, and certain control keys can be 
programmed to return special codes to the 
host computer. Typically, this will be to 
mimic certain keyboard codes the host 
computer's own keyboard may generate (eg. 
the arrow keys) or to provide shortcut keys 
to generate a sequence which on the host's 
keyboard may involve multiple or combined 
keypresses (eg. the function keys, or PgUp, 
PgDn etc.). The keyboard may also be re-
programmed to mimic another keyboard type 
which the host's own keyboard may not be 
capable of - eg. a DEC VT terminal. 

The keyboard map is entered from PC-Share's 
Config Menu by selecting Keyboard Map. From 
here, a sub-menu is displayed. Choose the 
Define Keymap from this menu.

The configurable keys are shown in the 
scrollable listbox. Each key may be 
assigned up to four 8-bit codes to be 
transferred when that key is pressed. 
Different sequences may be entered 
depending on if the shift or control key is 
held down at the time. A value of 0 
indicates the key has not been re-
programmed and will result in either no 
sequence being sent to the host computer 
(as in the case of function keys) or the 
`normal' value of the key. For example, the 
`Backspace' key will, by default send a 
code of 8 if pressed.

To view the settings for a given key, 
scroll to the required key and click on it 
using the mouse, or press the ENTER key. 
The values are displayed for all 3 key 
combinations. To change these values simply 
click or press ENTER again on the key. You 
will be required to enter a value in all 
the keyboard definition boxes, pressing the 
ENTER key between each one. When the entry 
is complete, a dialog box is displayed and 
you may resume displaying further keyboard 
definitions.

Keyboard map settings entered here only 
remain valid for the current session. To 
save them for use in the future use the 
Save Keymap option from the Keyboard Map 
menu. The settings can be reloaded in 
future by using the Load Keymap option.

Alternatively, to make the current settings 
the default for future sessions, goto the 
Save Config option of the Config Menu.
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File Menu

The File Menu of an active window controls 
the transfer of data to and from the 
screen/keyboard into disk files. There are 
3 options to this menu:

Import Text: Allows the transferal of an 
MS-DOS text file into the screen. When 
activated, a File dialog box will open 
requesting the name of the file to import. 
Text read from that file will then be 
passed to the host computer as if it had 
been typed in from the keyboard.

Export Text: Allows the transferal of a 
highlighted area of text on 

the screen to be copied into an MS-DOS 
file. When activated, a File dialog box 
will open requesting the name of the file 
for export. The contents of the highlight 
area will then be written to the file.

Capture: Allows the capture of outgoing 
text to be saved into an MS-DOS file. When 
activated, a File dialog box will open 
requesting the name of the capture file. 
Subsequently, all text (and any terminal 
emulator escape sequences) will be written 
to the file. In order to complete file 
capture, select the menu item again. 
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Edit Menu

The Edit menu allows the copying and 
pasting of areas of text currently 
displayed on screen. This is achieved 
through the use of a local 'clipboard' 
which text can be copied to and then later 
retrieved.

Copy: The current text 
selection on the window is 

copied as ASCII text to the clipboard. The 
selected area is unchanged.

Paste: Any text on the clipboard which is 
recognized as ASCII text is sent to the 
host computer as if it had been typed in at 
the keyboard. A maximum of 64Kbytes can be 
pasted at any one time.

Select All: The entire text contents of the 
screen is highlighted as the current text 
selection.

Mark: This option allows the keyboard to be 
used for selecting text instead of the 
mouse. See the Text 
Selection topic for details 

of this option.
@@
Text Selection

Any region of text on the screen may be 
selected using the mouse or keyboard. The 
entire screen can quickly be selected using 
the Select All function of the Edit menu. 
This text selection may then be copied to 
the local clipboard and later pasted to the 
host computer as if it had been re-typed on 
the keyboard. It may also be exported to a 
disk file using the File Export option from 
the File Menu.

Mouse selection is achieved by clicking and 
holding the left mouse button down and 
dragging the cursor to the end of the 
desired region. Once completed, release the 
mouse button. The area of selection will 
remain highlighted.

Keyboard selection is achieved using the 
Mark option from the Edit Menu. To begin 
selection, activate the Mark menu. The main 
menu will then clear. Using the arrow keys 
move the block cursor to the start of the 
block to be selected. Press the ENTER key. 
Again using the arrow keys, proceed to 
highlight the required selection. When 
done, press ENTER again.

Text selections will be cleared whenever 
any new text is output by the host 
computer.
@@
Text and Graphics

When the package is first started, PC-Share 
will display all text received by the host 
computer using the default screen colours. 
These may subsequently be altered by the 
user or host computer. This holds true 
whilst the PC is in text mode.

The host computer must put PC-Share into 
graphics mode to perform any graphical 
operations. The modes and colours available 
will depend on your graphics card, at best 
VGA 16-colour mode. When in graphics mode:

Text is displayed white on black.

The Main Menu, mouse and terminal emulation 
is disabled.

The host computer can initiate a number of 
graphics operations such as line draw, 
circle and individual points. Only the host 
computer can select text or graphics mode.

@@
MS-DOS File Access

A large part of the PC-Share message 
interface is in support of MS-DOS file and 
device access. The host computer may open 
any file or device which can be seen from 
the DOS command prompt for reading and 
writing. This includes hard disks, floppy 
disk, printers, serial ports and network 
drives. Device drivers written for the host 
computer will normally make the 
distinction between the host machine's own 
files and MS-DOS files as transparent as 
possible.

Files/devices may be read from or written 
to in binary (raw data) or text modes with 
full error reporting. Up to 64Kbytes of 
data may be transferred to/from the PC/host 
computer in one data stream. 

As well as general file access, PC-Share 
also provides a number of additional file 
operations, including file delete, change 
directory, make directory and directory 
reading capabilities. 

PC-Share also includes support for 
accessing the serial (COM) ports 
asyncronously using special dedicated 
software to allow full access to 
communications type (ie. modems) devices. 
The ports can also be configured under 
control of the host.
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Commands

Config Menu (Main Menu)
File Menu (Main Menu)
Edit Menu (Main Menu)
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Procedures

Hardware Settings
Configuration Directory
Terminal Emulation
Screen Colours
Keyboard Maps
Text Selection
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