CST

CST (Cambridge Systems Technology) were one of the early hardware designers for the QL, and used many of the QL standards developed by Tony Tebby.

They produced a wide range of hardware, including:

CST Expander
CST RAMPlus- RAM expansion with through port
CST Q488 - interface to connect a Sinclair QL to the IEEE 488 Instrument Bus
CST QDisk Interface - Standard disk interface
CST Q4 Interface - a device to allow you to connect 4 different interfaces to the QL at the same time
CST QPI Printer Module - a parallel port interface
CST SCSI Interface - an interface to connect SCSI devices to the Sinclair QL
CST Thor - a replacement for the Sinclair QL computer
CST Winchesters - Hard drives

In November 1985, CST also announced that they would offer their own internal 512K memory upgrades at a cost of £172.50, with a 90 day warranty, to cover the microdrive units.