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Model Information

[Hewlett-Packard LaserJet printer]

Model Data, LaserJet
Model Number 2686A
Introduction Date March 1984
Original MSRP $2,995
Replaces Model HP 2601A (Diablo 630)
Replaced by Model LaserJet Plus

Model Data, LaserJet Plus
Model Number 2686A-xxx
-200: 512K, Serial
-210: 512K, Parallel
-300: 512K, Parallel & Serial
-2MB: 2MB, Parallel & Serial
Introduction Date August 1986
Original MSRP $3,495
Replaces Model none
Replaced by Model LaserJet IID

[Hewlett-Packard LaserJet 500 Plus CXD-based printer]

Model Data, LaserJet 500 Plus
Model Number 2686D
Introduction Date August 1986
Original MSRP $4,495
Replaces Model none
Replaced by Model LaserJet IID

Model Data, Tempest Accredited
Model Number 2686TA
Introduction Date August 1986
Original MSRP <classified>
Replaces Model none
Replaced by Model none


The history of the development of the HP LaserJet and laser printers in general makes for interesting reading.

Printer Models


The original LaserJet only has 128K of RAM memory and the PCL Level is III, the "word processing level." Level III is a superset of Level I (Print and Space) and Level II (Electronic Data Processing). Lower level PCL implementations exist on other HP printers, the dot matrix printers (Rugged-Writers) and the ink jet DeskJets. The LaserJet has only two built-in fonts: Courier 10 portrait and Courier 10 landscape. Additional fonts could be added only by inserting cartridges. The LaserJet cannot accept downloaded soft fonts.

LaserJet Plus

The LaserJet Plus looks almost exactly like the LaserJet. A close examination of the control panel shows that the old continue button now says "HOLD TO RESET," in addition to "CONTINUE." The ready light also blinks when the printer is receiving data. The LaserJet Plus usually (but not always) includes a parallel port for easier connection to PCs. HP LaserJet Plus printers come in three interface options. Option 200 is serial-only. Option 210 is parallel only. Option 300 has both serial and parallel, but both cannot be enabled at the same time. Users may notice speed improvement when printing graphics through the parallel interface instead of the serial interface.

LaserJet Plus with 2 Megabyte Option

Another very expensive controller board that exists for the LaserJet Plus contains two megabytes of RAM. This board is fairly rare, as the price from HP was about $2,500 back in 1988. Again, the controller board is basically the same design, but the ROMs have been changed to access the larger RAM. The LaserJet Plus 2 MB board supports the parallel port and every other feature of the LaserJet Plus. This version of the controller was also sometimes installed in the "big guy" (the LaserJet 500 Plus).

LaserJet 500 Plus

The LaserJet 500 Plus uses the Canon CXD engine, which features two, 250-sheet paper trays. The CXD also has a clever output mechanism that is capable of correct order stacking (forward collated), as well as reverse collated like other CX engines. This amazing mechanism also reduces paper curl. The LaserJet 500 Plus was never quite as popular as the other LaserJets; its hefty size and price tag were probably the reason.

LaserJet 2686 TA: Tempest Accredited

The rarest of all original LaserJets was the tempest accredited 2686TA. It was designed to comply with NACSIM 5100A Tempest specifications. A special Tempest font cartridge had to be installed for the printer to operate, and the printer was sealed internally and externally to prevent tampering. This very limited production (and very expensive) unit had a metal enclosure mounted between the CX engine and the top of the printer to house the controller, thereby keeping Radio Frequency Interference to a minimum. This was very important to the military and defense intelligence departments; you don't want a printer to produce noise that would interfere with other equipment or become a signal allowing the enemy to discover the location of a war vessel.

Colors a different shade of beige

Like other LaserJets, the HP CXD covers are molded in slightly different color shades than the Canon standards, so when ordering cover parts, be sure to look at the item tables carefully to make sure you have the correct HP or Canon part numbers.

HP LaserJet and LaserJet Plus with Windows

The original Hewlett-Packard LaserJet (2686A) has only 128K of RAM and does not have the compressed font (16.7 pitch), Line Printer, that is offered with the later LaserJet Plus. The original LaserJet does not support the Page Formatting features of the later printers (setting page length, text length, margins, etc.), and its graphics ability is limited to character-based lines and boxes. It will work with Windows 3.1. Courier 10 pitch is the only resident font, but Windows 3.1 does support cartridge-based fonts. Metrics for the HP Pro Collection and the A-Z cartridges are included with the Windows driver and there is provision for adding other vendor-provided font metrics.

The Hewlett-Packard LaserJet Plus comes in two flavors: the common 512K version and the rare 2MB version. Both versions work well with Windows 3.1. The 512K version has limited graphics ability; it is able to print one-half to three-quarters of a page of graphics. The 2MB version can print full-page graphics. The caveat is that TrueType fonts print to the HP LaserJet Plus as graphics. Thus, a full page of TrueType text may not print on the 512K version. In addition to Courier 10 pitch, the Plus has Courier-Bold 10 pitch and Line Printer 16.67 pitch as resident fonts. Cartridge font support is the same as for the original LaserJet.

Differences between LaserJet and LaserJet Plus
LaserJetLaserJet Plus
128K of RAM 512K of RAM or 2 MB of RAM
Serial only Serial & Parallel
(word processing)
(page formatting)
No Macro Capability Macros
(ability to save long sequences of commands in memory)
Reset by Power Switch Only Reset Button (doesn't kill macros or soft fonts)
Original Control Panel Control Panel with "Activity" Light
Resident Fonts
Courier 10 Pitch in Portrait Courier 10 Pitch Portrait
Courier 10 Pitch Landscape Courier 10 Pitch Landscape
Courier Bold 10 Pitch in Portrait Courier Bold 10 Pitch Portrait
Courier Bold 10 Pitch Landscape Courier Bold 10 Pitch Landscape
Line Printer 16.67 Pitch
Character Sets
Basic HP Roman-8 P Roman-8, US-ASCII, and Extended Roman


When the LaserJet was introduced people were accustomed to getting by with just the 96 characters on the Diablo daisywheel. There were special daisywheels for different applications and languages, but it was usually impossible to get everything you wanted without making compromises. The original LaserJet had only fixed-pitch Courier 12 point in portrait and landscape, which isn't much by today's standards, but it included what is called the Roman-8 character and symbol set. The Roman-8 character set is an 8-bit extension to the 7-bit ASCII coding scheme. It includes 186 printable characters with most every accent, umlaut, ligature, thorn, monetary and other diacritical mark that most people ever needed for text. It was received as a tremendous improvement over daisywheels, but still wasn't sufficient for every need, so HP and others offered many additional character sets in different languages as well.

The original LaserJet could accept any of the original set of hard font cartridges, from HP part number 92286A through 92286Z. These fonts are well documented in the HP publication, LaserJet Printer Family Font Catalog (Part Number 33440-90910), which came in the box of the HP II.

As soon as the LaserJet came out, people realized that this compact and quiet desktop machine could churn out data processing reports as fast as the big 500 lpm line printers (so noisy that they were always kept away from the users in air-conditioned data processing centers). These paper-eating monsters consumed several boxes of green-bar paper a day and the print quality was lousy. Most people preferred high-resolution, letter-size output to the bulky, fan-fold green bar reports of the past. In order to be compatible with software that formatted output for wide paper, HP introduced the small Line-printer font. At 300 dpi, this small, phone-book style font was so readable that people no longer needed green or blue horizontal shading to scan across the page. By adding this font as standard equipment HP immediately gained a big new market for LaserJets. Corporate users purchased LaserJets as line printer replacements, and this turned out to be very lucrative for HP. The Line Printer font in landscape mode also allowed use of variable pitched fonts, far exceeding the capabilities of line printers. This became the font of choice for financial analysts producing spreadsheets prior to the introduction of Windows.

The additional memory of the LaserJet Plus could also be used for soft fonts. Soft fonts offered cost and flexibility advantages over hard font cartridges, but they were very slow to download (sometimes 20-30 minutes) and this time was always lost upon powering off the printer. In shared environments, one user's job might erase the fonts another user had spent a long time downloading. As a result, hard font cartridges containing the maximum number of fonts, such as IQ Engineering's Super Cartridge or Pacific Data Products' 25-in-1 cartridges, became the most popular font accessory for LaserJet and LaserJet Plus printers.

The LaserJet Plus has only six different bitmapped fonts, but this deficiency is made up for by the availability of hundreds of font cartridges. Another mitigating factor is that many software packages come with built-in soft fonts that are compatible with HP. The printer's resident fonts are Courier (10 cpi, 12 point), Courier Bold (10 cpi, 12 point), and Line Printer (16.67 cpi, 8.5 point), in both portrait and landscape versions.


Although the HP LaserJet, LaserJet Plus, and LaserJet 500 Plus have been discontinued, The Printer Works offers refurbished printers in like-new condition with a six-month warranty. For a price quote, select the part number of the model that interests you in the ordering information table.

Controller Notes

Model Information | Supplies and Accessories | Ordering Information | Text Only

[Hewlett-Packard LaserJet and LaserJet Plus Controllers]

Model and Controller Table
ModelPCL LevelRAMSerialParallel
2686A III 128K Yes No
LaserJet Plus
2686A-200 IV 512K Yes No
2686A-210 IV 512K No Yes
2686A-300 IV 512K Yes No
LaserJet 500 Plus
2686D IV 512K Yes No
2686D-300 IV 512K Yes Yes
LaserJet Plus / 500+ - 2MB
2686A/D-2MB IV 2 MB Yes Yes
300 x 300 for fonts
300 x 300 for 1/4 page of graphics
150 x 150 for full page of graphics

LaserJet Controller

The LaserJet controller was either part number SG4-6014, or SG4-6019. The -6014 controllers contain very early versions of the firmware that do not include all of the commands in the -6019. Both the -6014 and -6019 cards are considered PCL Level III. With just 128K of RAM, the LaserJet has only a tiny amount of RAM (56K) available for graphics. This amount of memory is enough for 5.4 square inches of 300 dpi graphics. There is no memory available for downloaded soft fonts. By reducing the graphics resolution to only 75 dpi, it is possible to print a full page of very jagged graphics on an original (non-plus) LaserJet. Provision for a parallel port exists, but either all IC locations are not populated with chips, or the firmware does not support receipt of data from the parallel port.

Conversion of LaserJet controllers to LaserJet Plus controllers is possible, but it is a very messy and difficult job that requires several cuts, many jumpers and a whole new set of PALS and ROMs from a real LaserJet Plus board.

LaserJet Plus Controller

The LaserJet Plus controller is basically the same circuit, but the two rows of 8 4164 RAM chips have been replaced by 16 41256 chips to give the plus 512K of RAM. With a half-megabyte, the LaserJet Plus can print a full-page of graphics at 150 dpi and/or a half page at 300 dpi. The part number for the LaserJet Plus controller without parallel I/O is SG4-6020 (Option 200). For option 210 (parallel only) and option 300 (parallel and serial) the controller board part number is SG4-6022.

To select the parallel port on the LaserJet Plus, switch number 1 of SW1 must be in the ON position. The OFF position indicates that either RS-232 or RS-422 is selected. This group of dip switches is located on the controller board. To access the controller board, the rear panel must be removed.

Supplies and Accessories

Model Information | Controller Notes | Ordering Information | Text Only
You can check prices or order these items from the ordering information table below.


The HP LaserJet, LaserJet Plus, and LaserJet 500 Plus use the same toner cartridges as all other CX-based printers.


The HP LaserJet and LaserJet Plus printers use the same shaped paper trays as all other CX-based printers. All versions are physically interchangeable, but there are slight color differences. (See also Diagram 300, Paper Cassettes for CX Engines.)

The LaserJet 500 Plus uses the same paper trays as other CXD printers.
(See Diagram 301, Paper Cassettes for CXD Engines.)


All models have the RAM soldered on the controller, with no provision for expansion. The only way to get more RAM is to exchange the controller.


Almost all CX-engine based laser printers can be converted to any other, usually with only the replacement of the Top Cover/Control Panel/Controller as a unit. Some conversions will also require the replacement of the Interface Bracket Assembly.

The recommended upgrades for the HP LaserJet (128K) are to an HP LaserJet Plus (512KB or 2MB version) or to a QMS-PS Jet Plus. The former gives you HP's PCL IV language and additional RAM for better graphics ability and page layout control; the latter gives you Adobe's PostScript language for desktop publishing applications, pre-press proofing, and Macintosh connectivity.

The recommended upgrades for the HP LaserJet Plus 512K version are to an HP LaserJet Plus 2MB version or to a QMS-PS Jet Plus. The additional RAM of the 2MB LaserJet Plus controller gives you better graphics ability. The only recommended upgrade from the 2MB LaserJet Plus controller, would be to the QMS-PS Jet Plus.

Ordering Information

Model Information | Controller Notes | Supplies and Accessories | Text Only
For price and ordering information or to place the item in your shopping cart,
select a Part Number in the table.
Part NumberDescription
2686A Printer, HP LaserJet 2686A 128K Serial Only, Refurbished
2686A-200 Printer, HP LaserJet Plus, 512K Serial Only, Refurbished
2686A-210 Printer, HP LaserJet Plus, 512K Parallel Only, Refurbished
2686A-300 Printer, HHP LaserJet Plus, 512K Parallel & Serial, Refurbished
2686A-2MB Printer, HP LaserJet 500 Plus, 2MB Parallel & Serial, Refurbished
2686TA Printer, HP LaserJet Tempest Accredited
SG4-6014 Controller, LaserJet (Early Version USA Only)
SG4-6019 Controller, LaserJet (USA and Foreign)
SG4-6020 Controller, LaserJet Plus, Option 200
SG4-6022 Controller, LaserJet Plus/500+ Option 210/300
SG4-6025-000 Controller, LaserJet Plus, 2 Megabyte Version
02686-90912 Manual, Technical Reference, HP LJ/Plus/500+
02686-90914 Operator's Reference Manual, HP LJ/LJ+
02686-90920 Service Manual, HP 2686A/D LaserJet
92235U Book, LaserJet Unlimited, Edition II, Peachpit Press
Model Information | Controller Notes | Supplies and Accessories | Text Only

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