The earliest known demo tape comes from 1986. The remixes on the end are reportedly bizarre sort of dub versions where the vocals pretty much cut in and out at random. It was apparently recorded at the music room of Abingdon School:

Fragile Friend
Girl (In The Purple Dress)
Everybody Knows
Mountains (On The Move)
Fat Girl
Lemming Trail
Lock The Door
Fragile Friend (Remix)
Lemming Trail (Remix)
Lock The Door (version)
In The Breeze

The recordings from this tape were the last to surface of all OAF demo tapes. They were uploaded to Youtube from October 2011 onwards by the member Klootme. She explained:
"History behind the tape is that my husband was at school with the band and partied with them (before Jonny joined them!). Phil was at Uni with us both in Liverpool. The demo was given to my husband at 17 in school. We used to go and see them play in Oxford and was friends with them. They were fairly inactive from 1987 -1990 as a band. But when everyone had finished Uni they got back together and tried to make a go of it. They went to the States...we went backpacking to India for 6 months. Six months later we retured from India...saw Colin with a binbag full of laundry at the lauderette....."so much for the States" we laughed......." I remember seeing them in Oxford where me and my husband made up an audience of 6!"

The next known demo tape comes from 1988, when the line-up of On A Friday temporarily included three saxophone players: Rasmus Peterson, Liz Cotton and Charlotte Cotton. The recordings were made at Woodworm Studios in Oxfordshire and engineered and mixed by Dave Pegg:

Happy Song
To Be A Brilliant Light
Sinking Ship

The next known tape comes from the summer of 1990. It's a compilation from recordings made from June through to August at Clifton Hampden Village Hall, Nuneham Courtenay Village Hall and at home on a 4-track. Apparently there is also a 14 track version with different sequence and some alternate titles:

Climbing Up A Bloody Great Hill
Mr. B [Jerusalem]
What Is That You See?
Dance Sucka
Upside Down
The Greatest Shindig Of The World
Give It Up
How Can You Be Sure?
Life With The Big F
Keep Strong
Burning Bush
Tell Me Bitch
New Generation

All the members were by this point at different Universities around the country, but reconvened over the summer, with the exception of Phil who was in Ireland. The band did not have a settled name during this period, having dropped On A Friday temporarily, but not come up with anything better. The band's working title was 'Shindig', which survived long enough for Thom to spray paint it on his acoustic guitar case, but by the time of their next 'proper' demo, they had reverted to On A Friday.

In order to keep recording and rehearsing a school friend, Nigel Powell, who had recorded some previous demos for the band, was drafted in to keep the drum stool warm. The Clifton Hampden tracks were recorded over a number of weeks with this line up, in between Jonny took the four-track home with him where he, Thom and Colin would continue working on the tracks. When Phil returned the band recorded another demo track in rehearsal, 'What Is That You See?'. 'The Greatest Shindig Of The World' - which would be rewritten as 'Maquiladora' - and 'How Can You be Sure?' would end up as b-sides on singles from The Bends.

The pages for each track contain further information.

In April 1991, during the Easter holidays, the band recorded this 3-track demo at Dungeon Studios on Ascott Hill Farm in Shipton-On-Stour, which had 16-track equipment. They worked there for three days, 10 hours each, which cost the band more than £300, an awful lot of money for them at the time. The recordings were engineered by the studio's owner, Richard Haines:

Two songs from the summer 1990 compilation were reworked for this tape, which also features the future Pablo Honey track and US single 'Stop Whispering'.
This tape helped the band get some regular live gigs, among them one at the Jericho Tavern on august 8th 1991, at which Chris Hufford saw the band for the first time. This demo tape and the gig convinced Chris Hufford and Bryce Edge to produce On A Friday's next demo at their studio.

The final pre-Radiohead demo was recorded in October 1991 on 24-track equipment for £500 at Courtyard Studios, owned by Hufford and Edge. Officially titled First Tapes, this became widely known as the "Manic Hedgehog Demo", named after the shop in Oxford that sold the cassette copies for £3 each:

Following the sessions for this demo, Hufford and Edge became the band's managers.

While working at the local record shop 'Our Price', Colin gave a copy of some of the band's demo recordings, which included 'Stop Whispering', to Keith Wozencroft, who had just become A&R for Parlophone and now did his best to convince his seniors of the potential he saw in this band. Following a gig in november, where scouts from some 25 record companies were present, On A Friday signed a six-album deal with Parlophone, a subsidiary of EMI, on december 21st 1991.

The version of 'Thinking About You' from First Tapes would reappear on Radiohead's first release on Parlophone, the Drill EP, which would also be recorded at Courtyard Studios in early 1992, a few months after this demo was taped there. Just in time for their first official release on a major label, the band finally changed their name to Radiohead.