Java Edition:Bed (Block Item)
Bed block items were obtainable in Beta 1.6 Test Build 3. They were deleted in 13w37a (1.7 snapshot). The bed block items will disappear from all inventories; they will not convert into a regular bed item. The bed block item stacks to 64, unlike regular beds, and when placed will create a bottom half bed block.
Obtaining
Indev Item Conversion
Spring green cloth from Indev had a numeric ID of 26, identical to bed. If spring green cloth is left in a chest and converted to Beta 1.3, it'll convert to bed. The conversion only occurs if the chest containing the item is not opened until Beta 1.3 or later, otherwise it'll cause the game to crash.
Beta 1.6 Test Build 3 Debug Chests
In Beta 1.6 Test Build 3, any newly generated world would contain up to 11 debug chests with every item in the game. The half bed item was obtainable in the chests 1st and 5th from the left in the 26th and 10th slots respectively, in stacks of 64.
