LineSim: PC Card Details

Building LINESIM onto an ISA PC prototyping card The cards mentioned here are for fitting into an ISA slot only. I have not attempted to create an example for the PCI bus, however the principle is the same. Power connection data is available on the web. Using a Commercial PC Prototyping Card Commercial PC prototyping cards consist usually of a board with a grid of individual holes each with its own isolated solder pad, plus an edge connector with a pre-cut slot to fit the ISA bus. This type of board is unsuitable for building this circuit directly. The solution is to build and test the circuit on a regular piece of stripboard, then mount the finished circuit onto the prototyping card. Note that this configuration may result in a card whose thickness causes it to overlap an adjacent slot. Alternatively, if you can obtain DIP type prototyping board which includes a 0.1 inch edge connector, you could build the circuit directly onto it, then cut a slot in the correct place on the edge connector to allow it to be plugged into an ISA slot. Using a Home Made PC Prototyping Card If you cannot easily obtain any form of suitable prototyping board, an alternative is to adapt an unwanted or faulty PC card. Such a card should not be too densely populated with components, particularly close to either end. The card must have a track from the +12v power pin on the edge connector. (Ninth pin from left on the solder side)

Using a fretsaw, cut approximately along the blue line on the left picture, cutting a radius at the corners to discourage cracking. Try to cut around components on the card. Discard (pun) the removed piece. Shape the stripboard you will use to build the circuit, so it fits snugly in the gap in the PC card. When the circuit is complete and tested, epoxy the board into place on the PC card as shown on the right. Socket Interfacing With the card completed and working correctly, the telephone sockets must be brought out to an accessible place. The telephone socket doubler can be connected to the card via a flylead about one metre long. The front edge of the card should be fitted with a female 9-way 'D' connector, wired to match the connector used on the flylead. Flush Mounted Line Sockets There is an attractive alternative to the labour and expense of making a trailing flylead. The telephone sockets can be flush mounted onto the front panel of the PC case. Usually there is a blanking plate covering an unused 3½" drive bay. This blanking plate can be modified to house the line sockets, allowing the telephone devices to be plugged straight into the front of the PC case! In practice, the bay itself may be occupied by a hard disk, however this should not present a problem. Proceed as follows: Remove the 3½" blanking plate from the PC case. Open the casing of the socket doubler and remove the small PCB that holds the two sockets. To allow entry of the line jacks, use the holes in the doubler's casing as a template to cut two corresponding holes in the removed blanking plate. Using a suitable length of six-core alarm/signalling cable, wire up the sockets as described elsewhere. The cable must be long enough to reach the card in its slot. At the other end of the cable, solder the conductors to their corresponding connections on the card. Test fit the socket/PCB assembly to the inner surface of the blanking plate. Ensure jacks can be entered and withdrawn correctly, then epoxy the socket assembly into place. When set, re-fit the modified plate into the PC case and insert the card into its slot. Ensure the connecting lead is routed safely.

Power Lead Connection Whatever type of PC card is used, the 0v and +12v connections must be made from the edge connector to the circuit board. Looking at the solder side of the card with the front panel (if fitted) on the left, the 0v lead goes to the leftmost pin (B1) on the edge connector. The +12v lead goes to the ninth pin from left (B9). Ensure correct polarity when connecting the power leads to the circuit board. To ensure that the cutting of the card did not cause any power rail short circuits, all other tracks going to the edge connector should be cut.

Building LINESIM onto an ISA PC prototyping card

The cards mentioned here are for fitting into an ISA slot only. I have not attempted to create an example for the PCI bus, however the principle is the same. Power connection data is available on the web.

Using a Commercial PC Prototyping Card

Commercial PC prototyping cards consist usually of a board with a grid of individual holes each with its own isolated solder pad, plus an edge connector with a pre-cut slot to fit the ISA bus. This type of board is unsuitable for building this circuit directly. The solution is to build and test the circuit on a regular piece of stripboard, then mount the finished circuit onto the prototyping card. Note that this configuration may result in a card whose thickness causes it to overlap an adjacent slot.
Alternatively, if you can obtain DIP type prototyping board which includes a 0.1 inch edge connector, you could build the circuit directly onto it, then cut a slot in the correct place on the edge connector to allow it to be plugged into an ISA slot.

Using a Home Made PC Prototyping Card

If you cannot easily obtain any form of suitable prototyping board, an alternative is to adapt an unwanted or faulty PC card. Such a card should not be too densely populated with components, particularly close to either end. The card must have a track from the +12v power pin on the edge connector. (Ninth pin from left on the solder side)

Using a fretsaw, cut approximately along the blue line on the left picture, cutting a radius at the corners to discourage cracking. Try to cut around components on the card. Discard (pun) the removed piece. Shape the stripboard you will use to build the circuit, so it fits snugly in the gap in the PC card. When the circuit is complete and tested, epoxy the board into place on the PC card as shown on the right.

Socket Interfacing

With the card completed and working correctly, the telephone sockets must be brought out to an accessible place. The telephone socket doubler can be connected to the card via a flylead about one metre long. The front edge of the card should be fitted with a female 9-way 'D' connector, wired to match the connector used on the flylead.

Flush Mounted Line Sockets

There is an attractive alternative to the labour and expense of making a trailing flylead. The telephone sockets can be flush mounted onto the front panel of the PC case. Usually there is a blanking plate covering an unused 3½" drive bay. This blanking plate can be modified to house the line sockets, allowing the telephone devices to be plugged straight into the front of the PC case! In practice, the bay itself may be occupied by a hard disk, however this should not present a problem.

Proceed as follows:
Remove the 3½" blanking plate from the PC case.
Open the casing of the socket doubler and remove the small PCB that holds the two sockets.
To allow entry of the line jacks, use the holes in the doubler's casing as a template to cut two corresponding holes in the removed blanking plate.
Using a suitable length of six-core alarm/signalling cable, wire up the sockets as described elsewhere. The cable must be long enough to reach the card in its slot.
At the other end of the cable, solder the conductors to their corresponding connections on the card.
Test fit the socket/PCB assembly to the inner surface of the blanking plate. Ensure jacks can be entered and withdrawn correctly, then epoxy the socket assembly into place.
When set, re-fit the modified plate into the PC case and insert the card into its slot.
Ensure the connecting lead is routed safely.

Power Lead Connection

Whatever type of PC card is used, the 0v and +12v connections must be made from the edge connector to the circuit board. Looking at the solder side of the card with the front panel (if fitted) on the left, the 0v lead goes to the leftmost pin (B1) on the edge connector. The +12v lead goes to the ninth pin from left (B9). Ensure correct polarity when connecting the power leads to the circuit board. To ensure that the cutting of the card did not cause any power rail short circuits, all other tracks going to the edge connector should be cut.