Laplink

Laplink (sometimes styled LapLink) was a proprietary piece of software developed by Mark Eppley and sold by Traveling Software.^[1] First available in 1983,^[1] LapLink was used to synchronize, copy, or move, files between two PCs, in an era before local area networks, using the parallel port and a LapLink cable or serial port and a null modem cable or USB and a USB adhoc network cable.^[2][3][4]

Traveling Software is now known as LapLink Software, Inc.,^[5] and their main software is now the PCmover. With the demise of parallel ports on PCs Laplink no longer sells the traditional cable. Instead it has USB to hard drive, USB to USB and Ethernet to Ethernet cables.^[6]

Cable

LapLink typically shipped with a specialized cable, allowing two PCs computers to be linked together via the parallel port, establishing a direct cable connection. This so-called LapLink cable or null-parallel cable is capable of faster transfer rates than the traditional null modem serial cable. At the time, almost all PCs had a parallel printer port, but neither USB nor modern Ethernet was available.

The INTERSVR program in MS-DOS 6.0 can also use a LapLink cable.

A Laplink cable can be seen as a parallel equivalent to a serial null modem cable. Because of the higher bandwidth of the parallel port versus the serial port, a Laplink cable is able to transfer data more quickly.

Wiring

The cable used two DB25 male connectors, and was wired as below:

D0	2	15	Error
D1	3	13	Select
D2	4	12	Paper Out
D3	5	10	ACK
D4	6	11	Busy
ACK	10	5	D3
Busy	11	6	D4
Paper Out	12	4	D2
Select	13	3	D1
Error	15	2	D0
Select In	17	19	GND
GND	18	18	GND
GND	19	17	Select In
GND	21	21	GND
GND	22	22	GND
GND	23	23	GND
GND	25	25	GND

See also

• Parallel Line Internet Protocol (PLIP)
• Direct cable connection
• Serial console
• Ethernet cable

References

1. LapLink Software, Inc. "About LapLink Software, Inc". laplink.com. About Us.
2. Traveling Software (14 February 1989). "Why Lap-Link Has Connected Over 200,000 Computers". PC Magazine. Vol. 8, no. 3. Ziff Davis, Inc. p. 92. ISSN 0888-8507.
3. Bem Cotterman (8 November 1994). "Laplink for Windows Takes Controls of Remote PC's". PC Magazine. Vol. 13, no. 19. Ziff Davis, Inc. p. 52. ISSN 0888-8507.
4. Steve Rigney (17 November 1998). "Access Your Office PC". PC Magazine. Vol. 17, no. 20. Ziff Davis. p. 73.
5. "About us", laplink.com
6. "Laplink Easy Transfer Cable For Windows® - Laplink® Software". www.laplink.com. Archived from the original on 2014-11-19.

External links

• Pin descriptions at Nullmodem.Com