I've just uploaded my regular D&D house rules to DriveThruRPG, at my Hidden Treasure Books storefront.
In it, you'll find rules for running a game somewhere between BX/BECMI style and AD&D style games, with mostly the simplicity of the box sets, but with separate race & class, and a few other complexities from AD&D (and a few more modern conventions I like such as ascending AC).
Ruby has rules for the following races: Humans, Dwarves, Elves, Gnomes, Halflings, Half-Orcs. As with AD&D, demi-humans have class restrictions and level limits, although a bit more generous than old Gary originally suggested.
And the following classes: Bard, Cleric, Druid, Fighter, Illusionist, Magic-User, Paladin, Ranger, Thief. Advancement goes to level 15.
Plus spells up to level 6, full equipment lists, and some handy rules for players to engage in exploration and combat, and some notes for higher level play.
As with TS&R Jade, this is Pay-What-You-Want so feel free to download it for free, or tip me a few bucks if you enjoy it and can afford it!