… was a 2400 bits per second one: absolutely cutting edge stuff compared to the 300 bps ones or the 1200 bps from them to you but only 75 bps from you to them (!) of the previous UK standards.

It was an Amstrad, and it came with a portable luggable PC clone called the PPC-640 thrown in.

(This was about the size and weight of two reams of heavy A4 paper short edge to short edge, 8MHz 8086-clone CPU, 640k RAM, twin 3.5" 720k floppies, small black and white LCD screen with no back light making it Somewhat Difficult to read unless you had a good light source behind you, and CGA graphics = 80×25 characters or 320×200 in four ugly colours, or 640×200 in black and white. Eight or ten D size batteries would run it for about an hour when disconnected from the mains.)

Doing it this way was, for a while, the cheapest way to get a 2400 modem! Some people bought one, attached their 'real' PC to the PPC's serial port and ran a small program on the PPC so their PC would think it was directly connected to the modem.

They cost about £800 new. I paid about £250 for a second hand one, less than a year after the launch.