This board gives a good schematic of the PERQ hardware and the main points:
CPU and Memory
16 bit ALU up to 1 Million PASCAL P-codes/sec
4K of 48 bit Writeable Control Store
256 Kbytes of 680ns cycle time
Input/Output
Z80 Microprocessor controlling
RS232
GPIB
IEEE 488
Speech Output
Storage
24Mbyte Winchester disc
1Mbyte floppy drive
The Winchester drive is mounted vertically and takes up the whole of the cabinet.
The 4K WCS (Writable Control Store) was a major problem early on
being only sufficient for handling the PASCAL P-codes so any other
extensions or change of operating system needed a larger
control store. The 256 Kbyte memory soon got increased to 512 Kbytes and eventually 1 Mbyte.