Based on Bill Verners' Inside the Java Virtual Machine, McGraw Hill Companies, 1997

baload - Load byte or boolean from array
  opcode:  51 (0x33)
  usage: baload
  stack before: ..., arrayref, i
stack after: ..., value
 
description: The Java Virtual Machine takes two top words from the stack. Arrayref must a reference to an array of bytes (or boolean)  and i must be an integer. As a result virtual machine pushes byte value from index i of array arrayref on the stack.
exceptions: NullPointerException - arrayref is null
ArrayIndexOutOfBoundsException - i is not a legal array index

bastore - Store into byte or boolean array
  opcode:  84 (0x54)
  usage: bastore
  stack before: ..., arrayref, i, value
stack after: ...
 
description: The Java Virtual Machine stores byte value in index i of array arrayref. Arrayref must be an array of bytes (or boolean), i must be an integer and value must be byte or boolean (depending on arrayref component type).
exceptions: NullPointerException - arrayref is null
ArrayIndexOutOfBoundsException - i is not a legal array index
ArrayStoreException - value is not the same type as arrayref

bipush - Push 8-bit signed integer
  opcode:  16 (0x10)
  usage: bipush byte
  stack before: ...
stack after: ..., value
 
description: The Java Virtual machine pushes an 8-bit signed integer byte on the stack.