And a wide variety of disk sizes and formats, HD IBM PC formatted 3.5" disks were 1.44Mb but some other systems could bump the capacity up to at least 1.6Mb, my GEM S2 keyboard formats disks to 1.6Mb for example.
Talking about Sinclair Computers, Alan Sugar (Amstrad) got wind that they were in serious financial difficulty (via Dixons I believe) and set in motion acquiring them. This process was going to take a little while, if it happened at all, but Dixons wanted a new Sinclair ZX Spectrum compatible machine to sell for the next Christmas. Alan set to work getting a new Sinclair machine designed and tooled up before the acquisition and set to lose a decent amount of money if the acquisition failed, which in the end was successful.
In the end the amount Amstrad paid for Sinclair's computer division was paid off by sales of the machines Sinclair already had sitting in warehouses.
Interestingly a localish second hand shop in Axminster has a CPC6128 with modulator for £100, previously they had two of them, although the other one was cheaper as it had no modulator (an easy fix). Originally the idea was they'd come with a monitor (so you didn't have to share the living room TV), and that monitor also powered the computer. They also used 3" Quick Disks rather than regular 5.25" or 3.5" disks.
Their first IBM compatibles also used the monitor for power meaning the machine didn't need a fan, one was later added unnecessarily to hard disc models to stop overheating rumors/lies supposedly pedaled by IBM.