There are 256 bytes of volatile "scratchpad" memory for storage of workspaces. The CU had sixteen 64-bit registers and a separate sixty-four slot 64-bit "scratchpad", LDB. It derives from the intuition of "memory" as a scratchpad. Two computer algebra systems named Scratchpad were developed by IBM. Stores and branches occur here, as well as writes to scratchpad addresses. It has been in development since 1971 by IBM, originally named "scratchpad". As before, one of the counters is used as scratchpad. Barry Trager who then shaped the direction of the scratchpad project took the project.