The drive was a special sprectrum only thing called a micro drive, they were a very small tape drive. I thought they had rear connections for a normal cassette player, which is what the normal spectrum 48k used.
I've still a Spectrum in the loft!! All the games are on cassette which needed to be loaded through the audio connections, on a basic Spectrum anyway.
The follow-up to the Spectrum was the Sinclair QL which included integrated microdrives -- the microdrive was simply a loop of tape in a miniature cassette style connection, unique to the Sinclairs.
At around the same time the QL came out with microdrives, a separate drive was made available for the Spectrum. There was a special interface that the spectrum had to be plugged into for it to be able to use microdrives.
TBH - I would probably use one of the available PC emulators to run Spectrum games, unless you really want to get one of the old things running! There are many games/softare freely available as ROMs on sites (including some of my old ones!!) - some even legally released by their authors.
Well I had never seen a spectrum ql. up until reading this post. I had the 48K spectum then the sincliar lowprofile keyboard for the 48K, then the +2 which has a standard tape deck attached and was 128k and my bros. had the +3 which like said earlier in this thead used 3" disks.
On another note did any one remember the sam coupe, it could load spectrum games but also could do graphics on the scale on the amega.
My cousin had a QL, I think it actually came with 2 micro drives but I remember him telling me that there were not that reliable. As somebody else mentioned they are basically and endless loop of tape in there.