WELLINGTON BUSINESS SERVICES.

 

 

PCW LinkIt User Documentation

Release of 12 April 1992

WARNING

If you plug the cable in to a PCW while the machine is switched on, you will almost certainly destroy the machine.

Believe us, we know, we did it!!!

Always attach a cable to a pair of machines whilst BOTH are switched off.

We strongly advise you to treat a pair of machines joined by a cable as ONE machine. Arrange that both are switched on and off SIMULTANEOUSLY, either by using one hand on each machine's on/off switch, or by connecting both to a single two-way mains adaptor, and switching on and off at the mains.

WARNING

Please keep metal objects clear of the metallic legs of the extended connector.

Please keep the cable clear of soldering irons, electric drills, arc-welders, and other sources of electrical interference.

General description.

The PCW LinkIt is a set of hardware and software designed to allow you to join together any two PCW series machines, of the old or new series, with any type of disc drive. Both ends are identical electrically, it does not matter which end goes to which machine, provided it fits mechanically.

Fitting the cable to a PCW 9256

You will need to gain access to the expansion connector at the bottom of the rear of the machine.

One end of the cable has an extended connector to reach the expansion socket on a 9256, which is deeply recessed. You will find that the extended connector has a "key" between the eleventh and twelfth pairs of terminals. This must be removed with a pair of tweezers or narrow nosed pliers before it can be pushed home onto the expansion connector. It is quite easy to remove, simply grasp firmly, pull out and discard.

IMPORTANT: Once you have removed the key, you could fit the connector to the machine in either orientation. Fitting it the wrong way round COULD DESTROY YOUR MACHINE.  When facing the REAR of the machine, the cable must emerge to the LEFT of the connector. That is to say the end nearest the adjacent side of the machine.

When fitting the cable to a PcW9256, keep it square on to the expansion connector, even though this means it will only touch the casing at the end nearer the centre of the machine. Resist the temptation to push the connector fully home, because this will result in it sitting skew on the expansion connector.

Joining two PcW9256 models would involve removing the case from one machine, since only one end of the cable is fitted with an extended connector capable of reaching the expansion connector on a PcW9256. We do not recommend this, and you undertake it at your own risk. Lethal voltages are exposed when the case is removed.

Fitting the cable to a PcW10 (this section added September 2002)

Follow the instructions for the PcW9256.

Fitting the cable to 9512 and 9512+

The cable is simply fitted to the expansion connector on the rear of the machine. Because there is a key fitted to the connector, it should be impossible to fit the cable wrongly. However just in case, check that the cable emerges towards the side of the machine, that is to say at the left hand side, when you face the REAR of the machine.

NB. (this added September 2002) The PcW9512+ has a plastic cover over the expansion port and this needs to be removed before a connection can be made.

Fitting the cable to 8256/8512

The cable is simply fitted to the expansion connector on the rear of the machine. Because there is a key fitted to the connector, it should be impossible to fit the cable wrongly, however just in case, check that the cable emerges towards the bottom of the machine.

Fitting the cable to a PcW16 (this section added September 2002)

The simple answer to this question is you cannot --- SO DO NOT TRY!

When you open the package:

It should contain a cable, two diskettes one 3" and one 3.5".

The diskettes are not copy protected. The 3" disc is PCW 8256 180K format. The 3½" disc is PCW9256/10/9512+ 720K format. Make copies of each diskette.

PCW9512.

You will need to format a 720K 3" disc and copy all of the files from the 3" 180K disc to the new 720K disc. This can be done inside Locoscript, by copying each file onto the memory M: drive and then back to the new diskette.  An alternative is to read your CP/M manual carefully and use PIP.   Under CP/M the only drive on a one-drive machine can be used as both A: and B:.  So PIP B:=A:*.* will work to transfer all files. The diskettes can even be one 180K and one 720K, which is very convenient.

NB. (this added September 2002) You could try 8000copy which can be found on your CP/M disc as this should copy the PCWLinkIt 180K disc to a 720K disc.

PCW 8256/8512/PcW9256/10/9512+

Locoscript or Disckit on the CP/M disc can be used for copying, though there is so little on the discs that copying the files one by one may still be faster.

If both machines you intend to use have 3" drives, simply make a suitable copy for each machine.

NOW WRITE PROTECT THE COPY YOU HAVE JUST MADE.

Starting the software:

Remove all diskettes from the drives!!!

Power on both machines simultaneously.

Insert into the main (A:) disc drives of each machine the CP/M discs issued with the machines.

If nothing happens, strike spacebar. Eventually activity should cease and you should see a line at the bottom of the screen "A>".

Remove the CP/M disc from each machine.

Place your copy of the issued software into the A: drive.

Type LINKIT, and hit return on each machine.

After some activity each screen will then come up with a blank screen except for a message saying it is trying to link to the other system. As soon as both machines reach this stage they should establish communications and change to a display very similar to the Locoscript main menu.

If this does not work, see the trouble-shooting guide.

If you have got this far, congratulations, the software is up and running.

Principles of operation.

Though the screen looks very similar to the Locoscript front panel, do not get carried away by the similarity. Not everything is the same.

Firstly the PCW LinkIt software only selects one drive at a time to display. On Locoscript you can simply scan across the contents of drive A: and on via B: (if you have one) to M:. The PCW LinkIt software requires you to specify a single drive at a time. This is the drive from which data will be sent, and more importantly, to which data will be received.

You can slew across the display to show all files on all groups, just as you can under Locoscript.

Use of SHIFT with the arrow keys is not supported.

On power-on the M: drive is selected, and the files, if any, on it are shown. You change to (log) another drive by pressing F1, and a single key drive identifier. You may need to be patient, logging a full drive is a little slow.

PCW Linkit only recognises drives A:, B: and M:. Anyone wanting a hard disc version or similar, please contact us!

If you remove a diskette from a drive, and replace it with another YOU MUST LOG THE NEW DISC IMMEDIATELY OR DATA MAY BE CORRUPTED.

Selecting files to transfer

You must select which files you wish to send to the other system. This is known as tagging them. You can see which files are tagged; they have little arrows at the left of their filenames on-screen pointing them out.

Simple tagging 1:

If you wish to tag an entire disc's contents simply press F4 (if you haven't yet used F2 or F3)

Simple tagging 2:

Move the highlight by using the up, down, left and right arrow keys to the files you wish to tag, and press the space bar at each one to tag them. Pressing the space bar on a tagged file untags it.

You can combine both the above to tag all files and then untag a few.

Single group tagging:

You can restrict the operation of F4 to a single group by using the F2 key. Simply press F2, and type a single group number. (The groups are numbered 0 to 7, starting at the top left, and proceeding first, down the left column, then down the right.)

You will see the number of the group you have selected displayed at the top left corner of the screen.

After this, F4 will only tag files within the nominated group. Of course you can work your way through a number of groups, the tagging stays set until the files are sent, they are explicitly untagged, or the disc is re-logged.

Tagging by filename matching:

To use this feature, you will need to understand the idea of an "ambiguous file name" abbreviated to afn.This should be well explained in your CP/M or DRDOS manual if the explanation here is unclear.

A filename normally consists of up to eight characters, followed by a ".", and then three more characters (actually the name always has 8 plus 3).   The ones you do not explicitly give are held as spaces.)   In an afn, you can replace any or all of these characters by a "?". When looking for a matching filename the system will accept any character in this position.

So ABCDEFG?. IJK will select files called ABCEDFG1.IJK, ABCDEFGH.IJK, ABCDEFG?.IJK, and ABCDEFG.IJK (space  = ?), but not BBCDEFGH.IJK.   NB It will not match ABCDEFG1, because the last three characters are spaces even though you have not mentioned them.

NB ABC? EFGH.??? will match ABCDEFGH, (? matches spaces too), ABCDEFGH.111 and ABCZEFGH.ABC.

You can abbreviate eight "?"s before the ".", and/or three "?"s after to a single * character. So ABCDEF? H.??? can be written as ABCDEF?H.*. ????????.DOC can be written as *.DOC, and most importantly ????????.??? can be written as *.*

*.* will match ANY and ALL filenames.

To tag a set of files all at once, you set up a matching filename, then use F4.

The filename is set up by using F3, and typing in a filename, which may include ? and  *. Finish with a RETURN. If you get it wrong, just hit RETURN, and do it again. The afn you have typed will be displayed at the top of the screen.

At power-on the afn is set to *.*, so all filenames will be matched by F4.

Simple example:

To tag all files whose names have the extension "LET", press F3 then type *.LET, followed by RETURN. The name *.LET will appear at the top of the screen. Pressing F4 will then tag all such files within the group(s) selected by F2.

Untagging::

F5 works just like F4, except that it UN-tags the matching filenames.

Sending files:

The disc to which files are to be sent must be formatted first, and must be suitable for writing in the drive in which it is inserted. It need not be empty, though of course it can be.

There is no restriction on the type of files that can be transferred. The software will work somewhat faster on text than on .COM files, but any type of file can be transferred.

FIRST ensure that the receiving system has logged the drive onto which you want the files to go!

Once you have tagged one or more files they can be sent to the other system simply by pressing F8.

You will see the highlight cursor move to each file to be sent in turn. Once it has been successfully transferred, that file is untagged, and the cursor will move on to the next. If the transfer is unsuccessful, the tag will remain in place, so you can for instance simply change a disc at the receiving machine and re-start the transfer.

The display on the receiving station does not show each file as it arrives. The screen will update after all reception ceases and show the new files. Be warned the file sizes may appear to have changed. That is because the files are stored in whole 1024 or 2048 byte blocks, and moving a file to a system with a larger block size can cause the size to be rounded up to the nearest boundary.

A file will always be stored on the receiving station under the same group as it came from on the transmitting station. The group may acquire the name from the transmitting station, see below.

Stopping operations in progress

You can normally stop the transfer of a long list of files by pressing the STOP key ONCE, on the machine that is sending files. You will have to wait until the current file has been finished with to see the effect, SO BE PATIENT.

Leaving the program

Pressing STOP when the program is waiting for instructions (the fourth line on the screen shows F1, F2 & etc) will cause the program to exit to CP/M.

A word of warning:

If you stop the program at one end of the link, and the wish to restart the link, YOU MUST FIRST STOP THE PROGRAM AT THE OTHER END. Then both ends can be restarted as before. Restarting one end without stopping the other will cause the still running program to become confused and freeze up. You will then have to go through the power-on sequence again.

Space:

The amount of space available on a disc is shown at the top of the screen, with the names of the groups.

Locoscript uses groups 8 to 15, which it keeps very quiet about, to store deleted files from groups 0 to 7. It calls these files "limbo" files, but CP/M, and PCW LinkIt, treat them as real. So a Locoscript disc may be said, by Locoscript, to have plenty of empty space, but PCW LinkIt and other CP/M programs may disagree, and find very little empty space. In this case, you can free the space up by asking Locoscript to display the Limbo files, and then deleting them one by one. Deleting Limbo files with Locoscript really does free up the space.

PCW LinkIt cannot "see" the limbo files, and never sends them to another system. If there are any Limbo files the space they are occupying will be shown on the screen.

Hidden files:

Locoscript uses "hidden" files (what CP/M calls System files) to store the Locoscript operating programs. They normally do not show up on Locoscript directory listings, and it would not be sensible to send them to a disc on a different computer with different hardware. PCW LinkIt cannot "see" such hidden files. If there are any hidden files the space they occupy will be shown at the top of the list of files in each group on-screen. The only place you would normally find hidden files is on a Locoscript Start-of-Day disc.

Directory slots:

Each disc format (memory, 180K, and 800K) has a set number of directory "slots". This is 64 for 180K, 256 for 800K, and variable for M:.

A small file will take up one slot. Large files will need extra slots for each 32K of their size. On different formats this figure may be different, 16K, 64K or whatever. The number of free slots is shown on-screen.

Stopping receive:

If a file to be received will not fit on the target drive, either because of inadequate space available, or because not enough slots are available, the reception of that file will be refused before transfer starts.

Group names:

The name of a group under Locoscript is defined by the presence of a zero-length file with the extension "GRP". These do not appear on Locoscript file listings, but do on PCW LinkIt. Sending such a file to the other system will cause an un-named group to become named. The effect is of having two such names present in a single group are not defined, so try to avoid it.

Transfer security.

All filenames and group names, and the contents of all files sent are checksummed, so it is highly unlikely that errors will be caused by the transfer process.

Equality between stations.

The two ends of a PCW LinkIt link are entirely equal. Neither is the master or a slave. They operate independently until one station is asked to send. Then the receiving station temporarily has its operation interrupted, and accepts files under instruction from the other station. Once finished it is again independent, and can, if it wishes, initiate a transfer in the opposite direction.

Any files tagged when a station starts receiving are untagged by the reception.

Progress messages:

Each station will show the name of the file being transferred at the top of the screen. The transmitter shows a count of bytes transferred so far.

After a transfer is finished, both stations should show a message to the effect that the transfer was successful.

Error messages:

If a file cannot be transferred because the receiving station would not have room then the whole transfer will stop, with an appropriate message on both screens. No attempt is made to transfer other, smaller tagged files. The untransmitted files remain tagged, and can still be transferred when the problem at the receiving station is sorted out.

If an error occurs in the checksums for either the filename or file contents then both stations will display an appropriate message. A checksum error in the filename will appear to the transmitter as a problem with disc space at the receiver, but the message on the receiver's screen will show the exact problem.

We do not expect you to get checksum errors. Please notify us if you see more than very rare occurrences of this problem.

After a problem with the checksum on a file's contents the file may be found to exist on the receiving station's disc. Its contents should be regarded as suspect!!!

Troubleshooting:

If the two machines both reach the stage of saying "Trying to connect to other system", and sit there then you have a hardware problem with your cable. Please contact us for further information.

If you are new to daisywheel printers, then be aware that it is possible to insert the daisywheel incorrectly, resulting in a document, which is the right "shape" on the printer, but contains gobbledegook in place of the correct words. Check for this by using the Locoscript "Direct print" facility.

Notes for CP/M and sophisticated users:

Programmers using User 8 to 15, please note! PCWLinkIt is not a disc copy program, and cannot "see" user numbers above 8.

PCW LinkIt does not deal with password-protected files.

PCW LinkIt does not deal with time stamped files

File attributes are NOT copied to the receiving station. All attributes are IGNORED, except System, which causes the files to be invisible to the user. Files with the SYS attribute set cannot therefore be sent. Files, which are RO on the transmitting station, will be RW on the receiver.

PCW LinkIt sets the handling of CTRL-C, CTRL_Q, CTRL-S, TAB, etc by use of BDOS call 109. It also redefines the codes produced by F1 to F8. After exiting the program, we suggest you reload CP/M.