The PERQ 1 CPU had a WCS comprising 4k words of 48-bit microcode memory. The later "PERQ 1A" CPU extended the WCS to 16k words. The PERQ 1 could be configured with 256 kB, 1MB or 2 MB of 64-bit-wide RAM (accessed via a 16-bit bus), a 12 or 24 MB, 14-inch Shugart SA-4000-series hard disk, and an 8-inch floppy disk drive. The internal layout of the PERQ 1 was dominated by the vertically mounted hard disk drive. It was largely this that determined the height and depth of the chassis.