Jump to content

Apple Personal LaserWriter SC

From RetroTechCollection
Apple Personal LaserWriter SC
Apple's service drawing of the Personal LaserWriter SC I/O board, with its two SCSI connectors and SCSI ID switch
Manufacturer Apple Computer, Inc.
Type Laser printer
Release date June 1990
Discontinued September 1993
Interface SCSI (two 50-pin connectors)
Compatible Macintosh with SCSI (QuickDraw)
Power 600 W maximum
Resolution 300 dpi

The Apple Personal LaserWriter SC is a 300 dpi, 4 page-per-minute laser printer that connects to a Macintosh over SCSI. Apple introduced it in June 1990 and discontinued it in September 1993.[1] It is a QuickDraw printer: the Macintosh builds each page and sends it over the SCSI bus, so the SC has no PostScript interpreter. It uses the same Canon LBP-LX engine, case and DC controller board as the Apple Personal LaserWriter NT; the SC I/O board, with its 53C80 SCSI controller, is the difference.[2][3]

Specifications

[edit | edit source]
Personal LaserWriter SC specifications[2]
Item Value
Engine Canon LBP-LX
Resolution 300 dpi
Speed 4 pages per minute
Processor Motorola MC68000, 7.275 MHz
ROM 32K
RAM 1.0 MB
Interface SCSI
Printing protocol QuickDraw
Paper 250-sheet cassette; 50-sheet multipurpose tray; optional 15-envelope cassette
Size and weight 9.8 in (24.8 cm) high, 15 in (38 cm) wide; 32 lb (15 kg)

Apple's later specification sheet gives the ROM as 16K, where the 1992 service guide gives 32K, and lists four 30-pin slots filled with 256K SIMMs to make the 1 MB.[1][2] The service parts list gives the SC's SIMM as a 256K part, 661-0402.[3]

I/O board and SCSI

[edit | edit source]

Apple's drawing of the SC I/O board shows two SCSI connectors, the SCSI ID switch between them, a 53C80 SCSI controller, a 68HC000 processor, two ROMs, the RAM SIMM sockets and a ZPRAM.[2] The SC appears on the SCSI bus as a device with its own address, set on the ID switch.

Set the SCSI ID switch to 7 to make the SC print its user test page at switch-on. It prints the page over and over until it runs out of paper. The test confirms that the SC I/O board works.[4]

The SCSI connectors use Apple's LaserWriter SCSI pinout, in which pins 1-12, 14-25, 35-37, 39, 40 and 42 are ground, 26-33 are data bits 0-7 and 34 is parity. Volume I printed pin 38 as +5 V; Apple's 1993 addendum corrects it to TERMPWR (terminator power).[5][6]

Faults specific to the SC

[edit | edit source]

Apple's Table C2, SC I/O Board Failure, works through the SCSI side before condemning the board:[7]

  1. Check that the SCSI cables and terminators are fitted correctly and secure.
  2. Check the cables and terminators themselves; replace any that are faulty.
  3. Check that no other device on the bus has the same SCSI address. If one does, change the address.
  4. Check that the LaserWriter SC driver is in the System Folder and selected in the Chooser.
  5. Try a different SC I/O board.

Engine faults are common to the whole family; see Apple Personal LaserWriter NT Troubleshooting Guide. Maintenance is on Apple Personal LaserWriter NT General Maintenance.

Documentation

[edit | edit source]
[edit | edit source]

References

[edit | edit source]
  1. ↑ 1.0 1.1 Apple, "Personal LaserWriter SC", Apple Support document 112503 (formerly SP441), retrieved 2026-10-02. Source for: 68000 at 7.275 MHz; QuickDraw; SCSI; 600 W maximum, 5 A, 2052 BTU/hour at 110-115 V, 50-60 Hz; 16K ROM; four 30-pin RAM slots holding 1 MB with 0.25 MB modules, 120 ns minimum; 4 pages per minute; 300 dpi; minimum life 150,000 pages; introduced 1 June 1990, discontinued 1 September 1993; 32 lb; 8 × 15 × 18.3 in.
  2. ↑ 2.0 2.1 2.2 2.3 Apple Computer, Inc., Apple Service Guide for LaserWriter Printers, Volume I (072-0631-B, January 1992), Personal LaserWriter tab, I/O Board Identification, p. 8, and Specifications, pp. 9-10 (PDF pp. 148-150), hosted as File:Apple LaserWriter Printers Volume I.pdf; described at Apple LaserWriter Printers Volume I. Source for: the NT, SC and LS I/O boards and their parts; I/O board specifications of the LS, SC and NT (processor, ROM, RAM, interfaces, printing protocols, built-in fonts); the Canon LBP-LX engine, 300 dpi, 4 pages per minute, paper feed, materials, capacities and printable areas; NT and SC 9.8 in (24.8 cm) high, 15 in (38 cm) wide and 32 lb (15 kg); LS 8 in (20.3 cm) high, 15 in wide and 31 lb (14.5 kg); 10-32.5 °C, 20-80% humidity; 100-115 V AC 50-60 Hz or 220-240 V AC 50 Hz.
  3. ↑ 3.0 3.1 Apple Service Guide for LaserWriter Printers, Volume I, Personal LaserWriter tab, Exploded View and Parts List, pp. 2-5 (PDF pp. 142-145). Source for: I/O boards for the LS (661-0631), NT (661-0565) and SC (661-0566); NT RAM SIMM 1 MB 661-0520, ROM SIMMs 1 MB at J2 (661-0570) and 256K at J3 (661-0602); SC SIMM 256K 661-0402; LS DRAM 256K × 4, 80 ns, 334-0114; DC controller PCBs 661-0567 (NT and SC) and 661-0650 (LS); fuser assemblies 661-0568 (110/115 V) and 661-0575 (220/240 V); power supply units 661-0569 and 661-0574 (NT and SC) and 661-0636 and 661-0637 (LS); high-voltage power supply PCB 661-0573; laser assembly 661-0571; scanner assembly 661-0572; transfer roller 870-0103; separation pad 870-0295; fan 720-0513; interconnect PCB 982-0048 (NT and SC); the solid LS bottom cover 949-0313 replacing either LS cover.
  4. ↑ Apple Service Guide for LaserWriter Printers, Volume I, Personal LaserWriter tab, Status Lights, p. 11, and Test Prints, pp. 12-13 (PDF pp. 151-153). Source for: the three status lights on the front access door; the I/O board self-test on the SC and NT; the SC and NT status light table; the LS lights showing paper jam or paper out only when used with the LS driver; the service test print button on the DC controller PCB on all versions; the SC user test print with the SCSI ID switch at 7; the NT user test print and its contents; the LS printing no user test print.
  5. ↑ Apple Service Guide for LaserWriter Printers, Volume I, Ports and Cables, Connector Pinouts, p. 6 (PDF p. 209). Source for: the Personal LaserWriter SC and LaserWriter II SC SCSI pinout.
  6. ↑ Apple Computer, Inc., LaserWriter Printers Volume I Addendum (Apple Service Guide, September 1993), Personal LaserWriter SC/NT/NTR/LS and LS/L, pp. 15-22 (PDF pp. 18-25), hosted as File:Apple Service Guide LaserWriter Printers Volume I Addendum Sept 1993.pdf; described at Apple Service Guide Laserwriter Printers Volume I Addendum Sept 1993. Source for: the SC, NT, NTR, LS and LS/L using the same print engine; the LS/L as a cost-reduced LS sold under the LS name, with parts not necessarily interchangeable, power switch on the right rear, solid rear cover and family number M2002, against the LS with its switch on the left rear, an opening for the I/O board bracket and family number M2000; the NTR as a networkable PostScript printer 3 to 5 times faster than the NT, with RS-232, RS-422 (LocalTalk) and Centronics ports; NT information in Volume I applying to the NTR and LS information to the LS/L; the corrected parts list (pp. 15-18); NTR and LS/L I/O board specifications (p. 21); the LS/L test button behind a cover on the rear panel (p. 21); the NT and NTR top-half printing fault (p. 22).
  7. ↑ Apple Service Guide for LaserWriter Printers, Volume I, Personal LaserWriter tab, Table C2, SC I/O Board Failure, p. 27 (PDF p. 167).


Retrieved from "https://wiki.retrotechcollection.com/index.php?title=Apple_Personal_LaserWriter_SC&oldid=23169"