At the time it was lightning fast, 1,5mbps IIRC . . . . I also used to have a comprehensive list of BT engineering codes & passwords for things like line checks, line upgrades, FREE CALLS etc. Many got changed as they leaked into the public domain . . . but a few still work.
Im not bullshitting when I say that in the Mid to late 90's I was a major player in the internet world. I was instrumental in setting up 'Freeserve' (it wasn't my idea) & channelled most of the funds into CUT that "FORCED" BT to introduce ADSL. I still have many friends in the engineering side of it, I sponsored most of the top earners that wrote the router tables that make all this work.