The Z80 could only access 64 KB of RAM at a time. Software could work round this by bank switching, accessing different banks of memory at different times but this made programming more complex and slowed the system down. Each PCW's CP/M application could not use more than 64 KB so the system used the rest of the RAM for a RAM drive. On the other hand, the standalone Locoscript word processor program was reported as using up to 154 KB as normal memory and the rest as a RAM disk.