The Ilyushin Il-86 had airstairs which came out the left side of the rear fuselage. Once inside at the level of the baggage hold, one then turned left and up another set of fairly steep stairs into the rear of the cabin. Disabled access didn't appear to figure in the design, nor did the designer seem concerned about maximising the use of internal space.
I flew in one Heathrow to Sheremetzevo (Moscow) in December 1991, and the internal stairs, along with the humungous cast aluminium lever on the upstairs emergency exits and the 'take no prisoners' appearance of the Aeroflot hostesses, left a lasting impression.
Rear airstair:
http://cdn-www.airliners.net/aviatio.../1/1643137.jpg
Front Airstair:
http://cdn-www.airliners.net/aviatio.../6/0914613.jpg
A good shot of the steps stowing:
http://www.planes.cz/photo/1004/1004...e-prg-lkpr.jpg
This shows it well:
http://cdn-www.airliners.net/aviatio.../9/1267992.jpg
At an internal Airbus presentation in 2004-ish, the speaker suggested that the A320 replacement could resemble an Il-76 with a pair of rear-mounted engines (well, that's how I visualised his description). The reasoning being that budget airlines were not bothered about top speed. However, sitting on the ground waiting for the steps to turn up cost them money, so future designs would be low to the ground to minimise airstair height.