From Brendan Fankboner's original workprint companion

As you can see, this version is the most "radically different" edition of Blade Runner, as compared to other cuts. Other differences are that, after 1982, the only version to exist of this print is a 70 millimeter blow-up, in six-track Dolby Stereo. The blow-up process clips six percent off of the edges, as compared to 35 millimeter anamorphic prints. However, the six-track sound mix separates the bass and music from the dialogue and sound effects, to hold their own independence within the sound mix. Vangelis’ music has an aural, enveloping quality to it in this print, despite the rough qualities of the mix. In 1990 and 1991, some Landmark theaters in the Los Angeles area played this version as an anamorphic, 35 millimeter reduction print from the 70 millimeter blow-up. The print was reported to be of poor quality: grainy, non-color-corrected, and with "wobbly", hastily cut-in end credits (which also showed up in the " Director’s Cut"). A new, final credit was added to the 35 millimeter reduction: This version copyright 1991 The Blade Runner Partnership. The 70 millimeter blow-up resurfaced, briefly, and by mistake, at the Landmark Egyptian theater in Seattle during late January of 1999. It has also been reported as surfacing, again, in the Los Angeles area, in 1999. Let’s hope that the next time this rougher, but yet exciting, cut of Blade Runner makes it’s appearance, it is as an official video release!

Source at: http://media.bladezone.com/contents/film/workprint/