Apple Personal LaserWriter NT
| Apple Personal LaserWriter NT | |
|---|---|
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|
| Apple's service drawing of the Personal LaserWriter NT I/O board, the board that distinguishes the NT from the SC and LS | |
| Manufacturer | Apple Computer, Inc. |
| Type | Laser printer |
| Release date | July 1990 |
| Interface | LocalTalk (RS-422, mini-DIN-8), RS-232 serial (DB-25) |
| Compatible | Macintosh; MS-DOS computers by LocalTalk card or serial cable |
| Power | 600 W maximum |
| Resolution | 300 dpi |
The Apple Personal LaserWriter NT is a 300 dpi, 4 page-per-minute PostScript laser printer that Apple introduced in July 1990.[1] It is one of a family of five printers built on the same Canon LBP-LX engine, which differ in their I/O board: the QuickDraw Apple Personal LaserWriter SC (SCSI) and Apple Personal LaserWriter LS (serial), the cost-reduced LS/L, and the faster PostScript Apple Personal LaserWriter NTR.[2][3] The NT is the PostScript member of the 1990 line-up. Its I/O board carries a Motorola 68000-family processor at 12 MHz and PostScript in ROM, with Diablo 630 and HP LaserJet Plus emulations selected by a thumbwheel on the back panel.[2][4]
Specifications
[edit | edit source]| Item | Value |
|---|---|
| Engine | Canon LBP-LX laser xerographic engine |
| Resolution | 300 dpi |
| Speed | 4 pages per minute |
| Processor | Motorola MC68000, 12 MHz (the board drawing labels the chip 68HC000) |
| ROM | 1.25 MB, expandable to 2.0 MB |
| RAM | 2.0 MB |
| Interfaces | AppleTalk (RS-422), RS-232 |
| Printing protocols | PostScript, Diablo 630, HP LaserJet |
| Paper | 250-sheet cassette (20 lb paper); 50-sheet multipurpose tray (5 envelopes); optional 15-envelope cassette; letter, legal, A4 and B5 |
| Paper weight | 20 lb recommended; 16 to 28 lb accepted |
| Power | 100-115 V AC, 50-60 Hz, or 220-240 V AC, 50 Hz |
| 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 RAM as two 30-pin SIMM slots holding 2 to 8 MB with 1 MB or 4 MB SIMMs of 120 ns or faster, the maximum power as 600 W, the life as 150,000 pages and the height as 8 inches.[1] The 1992 service guide gives 9.8 inches for the NT and SC.[2]
The built-in fonts are ITC Avant Garde, ITC Bookman, Courier, Helvetica, Helvetica Narrow, New Century Schoolbook, Palatino, Symbol, Times, ITC Zapf Chancery, ITC Zapf Dingbats and the IBM PC Graphics Extended Character Set.[2]
I/O board
[edit | edit source]The I/O board sits at the top of the printer under upper and lower I/O shields and connects to the engine through an interconnect PCB that the NT shares with the SC.[5] Apple's drawing shows the mode switch, an RS-232 connector, an RS-422 (AppleTalk) connector, a RAM SIMM socket, the ROM and two ROM SIMM sockets, and the 68HC000 processor. The NT's ROM SIMMs are a 1 MB part (661-0570) at J2 and a 256K part (661-0602) at J3; its RAM SIMM is a 1 MB part, 661-0520.[2][5]
Mode switch
[edit | edit source]The thumbwheel on the back panel chooses the port and the printer language at switch-on. Apple's table gives the serial settings in the order speed, parity, data bits, stop bits, handshake and mode; values in brackets can be changed by software. Apple prints "std" for the data bits in positions 1 and 4.[4]
| Position | 8-pin (RS-422) port | 25-pin (RS-232) port |
|---|---|---|
| 0 | AppleTalk, PostScript batch mode | Serial, no input |
| 1 | Serial (9600, N, std, 1, XON), PostScript batch | Same |
| 2 | Serial (9600, N), 8, (1, XON), HP emulation | Same |
| 3 | Serial (9600, N), 8, (1, XON), Diablo emulation | Same |
| 4 | Serial 1200, N, std, 1, XON, PostScript batch; prints a diagnostic page in place of the start-up page | Same |
| 5 | Serial (9600, N), 8, (1, none), PostScript batch | Serial (9600, N), 8, (1, DTR), PostScript batch |
| 6 | Serial (9600, N), 8, (1, XON), PostScript binary | Same |
| 7 | AppleTalk, PostScript batch | Serial, no input |
To print from an MS-DOS computer over the serial port, connect a serial cable (with a DB-9 to DB-25 adapter if needed) to the printer's 25-pin port, set the thumbwheel, switch on and check the start-up page for the mode, then type MODE COM1:96,N,8,1,P and MODE LPT1:=COM1: at the DOS prompt.[4]
Ports
[edit | edit source]The 8-pin port is a mini-DIN-8 with the same RS-422 pinout as the LaserWriter II NT, NTX, IIf and IIg: 1 handshake out, 2 handshake in, 3 TxD−, 4 signal ground, 5 RxD−, 6 TxD+, 7 general-purpose input, 8 RxD+. The DB-25 port uses pins 1 (signal ground, SGND), 2 (TxD), 3 (RxD), 4 (RTS), 5 (CTS), 6 (DSR), 7 (signal ground), 8 (DCD), 20 (DTR) and 22 (ring indicator).[4]
Start-up page
[edit | edit source]The NT prints a user test page at every switch-on. It shows the operating mode (PostScript, Diablo 630 or HP LaserJet Plus), whether RS-232 or AppleTalk is selected, the number of fonts in ROM, the RAM fitted and the number of pages the I/O board has printed.[6]
Known faults
[edit | edit source]- An NT that prints only the top half of the page and leaves the bottom half blank needs a new fuser bulb or fuser assembly, according to Apple's 1993 addendum.[3]
- Faults on the NT I/O board are narrowed down with Apple's LaserWriter II Test Connector on the 25-pin port, which makes the status lights name a failed RAM SIMM or ROM SIMM. The table is on the troubleshooting page.[7]
Maintenance and troubleshooting
[edit | edit source]Apple documents the SC, NT, LS, LS/L and NTR together, and the procedures for the whole family are on:
- Apple Personal LaserWriter NT General Maintenance: safety, the Cleaning Page, Apple's cleaning table, registration adjustment and memory.
- Apple Personal LaserWriter NT Troubleshooting Guide: Apple's flowcharts, status light codes and lettered troubleshooting tables with their connector-pin readings.
Documentation
[edit | edit source]- Apple LaserWriter Printers Volume I, Personal LaserWriter tab (January 1992)
- Apple Service Guide Laserwriter Printers Volume I Addendum Sept 1993
- Service Training Personal Laserwriter Sc Nt Ls Service Course Version 1.1 1996
Related pages
[edit | edit source]- Apple Personal LaserWriter SC, Apple Personal LaserWriter LS, Apple Personal LaserWriter NTR
- Apple Personal LaserWriter 300 and Apple Personal LaserWriter 320, the later Personal LaserWriters on a different engine
- Apple LaserWriter II NT
References
[edit | edit source]- ↑ 1.0 1.1 Apple, "Personal LaserWriter NT: Technical Specifications", Apple Support document 112414 (formerly SP439), retrieved 2026-10-02. Source for: 68000 at 12 MHz; PostScript, Diablo 630 and HP LaserJet; LocalTalk and RS-232/RS-422 serial; 600 W maximum, 5 A, 2052 BTU/hour at 110-115 V, 50-60 Hz; 1.25 MB ROM; two 30-pin RAM slots, 2 to 8 MB, 120 ns minimum, 1 and 4 MB sizes; 4 pages per minute; 300 dpi; minimum life 150,000 pages; introduced 1 July 1990; 32 lb; 8 × 15 × 18.3 in.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 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.
- ↑ 3.0 3.1 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).
- ↑ 4.0 4.1 4.2 4.3 Apple Service Guide for LaserWriter Printers, Volume I, General Information, Connecting to a Macintosh Computer and Connecting to an MS-DOS Computer, pp. 2-5 (PDF pp. 197-200), and Ports and Cables, Connector Pinouts, p. 5, and Switch Configurations, p. 11 (PDF pp. 208, 214). Source for: the NT connecting by AppleTalk; connecting the NT to an MS-DOS computer with a LocalTalk PC Card or a serial cable to its 25-pin port; selecting PostScript (batch or binary), Diablo 630 or HP LaserJet Plus with the pushwheel switch; the DOS commands MODE COM1:96,N,8,1,P and MODE LPT1:=COM1:; the RS-422 and RS-232 pinouts; the thumbwheel switch settings and position 4 printing a diagnostic page.
- ↑ 5.0 5.1 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.
- ↑ 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.
- ↑ Apple Service Guide for LaserWriter Printers, Volume I, Personal LaserWriter tab, Table C3, NT I/O Board Failure, p. 28 (PDF p. 168).