Atari 825
| Atari 825 | |
|---|---|
.jpg) |
|
| The Atari 825 on the cover of its operator's manual | |
| Manufacturer | Centronics, for Atari, Inc.[1] |
| Type | 80-column dot matrix impact printer |
| Release date | 1980[1] |
| Price | US$999.95 (announced June 1980)[1] |
| Interface | 7-bit parallel, 40-pin edge connector, through the Atari 850[2] |
| Compatible | Atari 400 and Atari 800 with an Atari 850 Interface Module[2] |
| Dimensions | 14 1/2 in wide, 5 in high, 11 in deep (368 × 127 × 279 mm)[2] |
| Weight | 12 lb (5.4 kg)[2] |
| Power | 115 V AC, 60 Hz, 100 W, built-in supply[2] |
The Atari 825 is an 80-column dot matrix impact printer that Atari sold for the Atari 400 and 800. It prints lines up to 8 inches long in three character sets and is controlled by 19 control codes from the computer. It has a parallel interface, so it connects through the Atari 850 Interface Module, which converts the computer's serial I/O data to 7-bit parallel data.[2] Centronics built it for Atari from its Model 737, and Atari's field service manual covers the 825 (Centronics 737) and the updated replacement model, the Centronics 739, which it describes as identical in theory and operation.[3][1]
Atari introduced the 825 at the Winter Consumer Electronics Show in January 1980, again promised it for the summer at US$999.95 at the Summer CES in June 1980, and shipped it, by the FAQ's estimate, in the autumn of 1980. From May to August 1981 Atari offered it at US$800 instead of US$1,000. The FAQ notes that Atari sold the 825 only in the United States, and only in a 120 V version.[1]
Specifications
[edit | edit source]| Item | Value |
|---|---|
| Character sets | Monospaced 7 × 8 at 10 cpi; condensed at 16.7 cpi; proportional N × 9, average 14 cpi |
| Characters per line | 80 at 10 cpi; 132 at 16.7 cpi |
| Speed | 50 cps at 10 cpi; 83 cps condensed; average 70 cps proportional |
| Print line | 8 in maximum, printing left to right only |
| Carriage speed | 5 in/s forward, faster on return |
| Line feed | 6 lines per inch; 12 line feeds per second |
| Paper | Cut sheets up to 8 1/2 in; rolls 3 1/2 to 8 1/2 in wide, 5 in diameter, 1 in core; fanfold 9 in pin to pin, 9 1/2 in overall |
| Ribbon | Centronics Zip-Pack continuous loop, Atari CA016087 |
| Input | 7-bit parallel ASCII, 40-pin edge connector, up to 2,200 characters per second |
The FAQ gives the proportional speed as 79 characters per second on average, against the operator's manual's 70.[1][2]
Hardware
[edit | edit source]One printed circuit board holds the logic, the control and drive circuits and the power supply.[3] The parts list names an 8049 microprocessor, an 8755 EPROM and an 8156 RAM, with 2N6388 solenoid drivers and a 7407 driver.[3] The nine-wire solenoid print head rides on a carriage driven by a DC motor. A Hall effect sensor and a magnetic rotor on the head carriage produce the column sense pulses that time the printing. A four-phase stepper motor turns the paper drive roller, eight steps to a line of 1/6 in, and a 24 V AC motor drives the ribbon. The ribbon motor runs except when the carriage sits at the left margin.[3]
Power supply
[edit | edit source]Transformer T1 steps the mains down to 25 V AC centre-tapped, rectified by CR5 and CR6 into the 10,000 µF filter capacitor C3, which charges to about +17 V before heavy loading. That unregulated +17 V drives the solenoids and the carriage motor. Three regulators run from it: VR1 for the external +5 V that tells the 850 the printer is on, VR2 for +12 V for the motor drive, and VR3 for the +5 V logic supply. C5, C6 and C7 filter their outputs, and the power LED, DS1, lights when the +5 V logic supply is working.[3]
A small flyback protection board plugs into J004 on the logic board. Its diodes and zeners protect the solenoid drivers, and each solenoid has a 2.5 A fuse in series. The board also resets the processor and removes power from the motor and solenoids if the column sense pulses stop for about 250 ms while the motor or a solenoid is powered, as happens with a head or paper jam.[3]
The line fuse F1 is a 1 A slow-blow cartridge fuse on the right front corner of the logic board, under a clear plastic high-voltage shield beside the transformer.[2][3]
Maintenance and faults
[edit | edit source]Atari's operator's manual sets out ribbon changing, cleaning and lubrication at each ribbon change and every six months, and fuse replacement. The field service manual adds a detailed troubleshooting chart and three adjustments: the print head gap, the clearance of the Hall effect sensor and the print speed.[2][3] These are covered in the Atari 825 Maintenance Guide and the Atari 825 Troubleshooting guide.
The 825 has mains voltage inside the case at the line cord, the fuse and the transformer. Switch off and unplug it before removing the covers.[2]
Documentation
[edit | edit source]- Atari 825 Documentation: the field service manual and the operator's manual, with contents and notes.
- 825 Printer Field Service Manual
- 80-Column Printer Operator's Manual (C015506, 1980)
Related pages
[edit | edit source]- Atari 825 Maintenance Guide
- Atari 825 Troubleshooting
- Atari 825 Documentation
- Atari 850
- Atari 820
- Atari 822
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Michael D. Current (ed.), Atari 8-Bit Computers: Frequently Asked Questions, comp.sys.atari.8bit FAQ, last modified 2 August 2026: section 4.1 (the Atari 820, 822 and 825 printers) and section 11.1 (history, 1980 and 1981). mcurrent.name. Community reference.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 Atari, Inc., 80-Column Printer Operator's Manual for the Atari 825 (C015506, 1980): introduction and printer interface p. 1, installation p. 5, owner maintenance pp. 29-33, troubleshooting p. 35, specifications pp. 37-38, order numbers p. 39. Hosted here as File:Atari 825 80-Column Printer Operator's Manual C015506.pdf.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Atari, Inc., 825 Printer Field Service Manual (region distribution only, undated): introduction (PDF p. 2); description pp. 1-3; theory of operation pp. 4-15 (ribbon motor, power supply and flyback protection p. 11); parts list p. 51. Hosted here as File:Atari 825 Printer Field Service Manual.pdf.