The RTC Multi-link is a hardware/software networking solution for the Commodore 8-bit link of computers, and compatible with the following machines:

Commodore 64 Breadbin (long board)
Commodore 64c Slim case (short board)
Commodore SX-64 (Executive/portable)
Commodore 128
Individual Computers Reloaded V1
Individual Computers Reloaded V2
Gideon's Ultimate 64 (all versions)

This product/item is a Commodore 64 Single Multi-Link network satellite cartridge with one cable on the re-useable spool, to be used with the RTC Multi-Link system.  This cartridge is not compatible with the 128.  If you'd like a satellite cartridge compatible with the 128, see the Multi-Link 128 cartridge item.

To use this item, you will also own a Multi-Link master cartridge.  Take note that the maximum number of networked machines on this system is 6 + master.  This cartridge will be configured as satellite number 1.  If you'd like this cartridge pre-configured to a number other than 1, please send a message once payment has been completed.

When setting up your network hardware, the "grey" cased cartridge is the "Master" control cartridge (not included), that is inserted into the computer that will function as the master control machine.  This must be a Commodore 64, and cannot be a 128.  Each satellite cartridge plugs into the cartridge port of the machine to become part of the network.  The ribbon cables connect the grey master cartridge to the satellite cartridges.  The order in which they are connected is not important.  The first cable plugs into the grey master cartridge, and the other end of it connects to the first computer in the network.  Then next satellite is linked daisy chained in.  

The cables that plug into the top of the cartridge only plug in one way, as the connector is keyed.  The other end of the cable is marked as to which side is up.

The Multi-Link128 cartridge is unique in that, it requires you connect two "sync" wires inside your computer.  Each wire is marked to identify the correct location.  Once installed, to activate the cartridge, power on your 128 while holding down the C= (Commodore) key.  Once you see the traditional Commodore 64 blue screen and the Multi-Link text at the top of the screen, you'll know you installed it correctly.

Follow the instruction manual available for download for complete network setup and configuration.