The PERQ Computer

Original Article ↗ Hacker News Discussion ↗

Role of PERQ in GUI and Workstation History

  • PERQ is highlighted as a lesser-known commercial system between Xerox Alto and Apple Lisa/Mac.
  • Commenters compare it to contemporary systems: Lilith, Lisp Machines, Xerox Interlisp-D, Smalltalk-80 workstations, and early Sun/HP machines.
  • Consensus: PERQ is more “in the timeline” than directly ancestral to Lisa/Mac; Apple drew much more directly from Xerox PARC’s work.

Hardware, Microcode, and P‑Code Debate

  • PERQ used a microcoded, bitslice CPU (e.g., 74S181 ALUs, Am2910 sequencer) with a writable control store.
  • It supported multiple microcode “personalities” and OSes; microcode was loaded at boot via a Z80 on the I/O board.
  • Disagreement over whether PERQ was truly a “Pascal machine”:
    • One side: native instruction set is a Pascal-style P‑code (Q‑code), so it’s effectively a P‑code machine.
    • Other side: microcode executes its own 48‑bit microinstructions and interprets P‑code; P‑code is only one of several supported instruction sets.
  • Both sides agree that user-writable microcode and fast bytecode interpretation were central design goals, and that “emulation vs native” is mostly a terminology issue.

GUI, Usability, and Applications

  • PERQ GUI is described as minimalist monochrome windows, fast on limited RAM and disk.
  • Some recall tiled window managers and mouse-driven environments; others note that screenshots don’t show later hallmarks like menu bars, standardized buttons, or desktops.
  • Broader context: early UIs (Smalltalk, Interlisp-D, Lisp Machines, Mac, HyperCard) differed greatly; “direct manipulation” as a formal concept only emerged in the early 1980s.

Software and Lisp Heritage

  • SPICE project on PERQ produced Spice Lisp, which evolved into CMU Common Lisp and then SBCL; Hemlock editor also originates here.
  • PERQ’s Accent OS influenced Mach, which later underpinned NeXT and then Mac OS X.
  • Discussion links these lines to broader language evolution (Mesa→Modula-2→Oberon/Modula-3, Smalltalk’s influence, etc.).

Geography and Industry Structure

  • Thread debates whether the 1970s computing industry was more geographically “inclusive.”
  • Some argue concentration in a few “champion cities” has grown; others counter with lists of recent hardware companies across many Chinese and global cities, claiming more geographic dispersion today.
  • No consensus; metrics for “inclusivity” deemed unclear.