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Atari 1020

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Atari 1020 Color Printer
Atari 1020 colour printer/plotter
Manufacturer Atari, Inc.; mechanism by ALPS
Type Four-colour X-Y plotter
Release date Introduced December 1982; shipping from spring 1983[1]
Price US$299 (1983)[1]
Interface Atari SIO, two I/O connectors, 19,200 bit/s[2]
Compatible Atari 8-bit computers[2]
Power External AC adaptor; on-board rectifier and two 5 V regulators[2]
Media Roll paper about 4.5 inches (11.5 cm) wide[3]

The Atari 1020 Color Printer is a 40-column, four-colour printer/plotter for the Atari 8-bit computers. Atari introduced it in December 1982 together with the 1200XL, the 1010 program recorder and the 1025 printer, and shipped it in spring 1983 at US$299.[1] It draws text and graphics on a roll of narrow paper with four pens held in a rotating barrel, moving the pens across the paper and the paper up and down.[2][3]

The mechanism is an ALPS design used in several other low-cost plotters of the time, including the Commodore 1520, the Oric MCP-40 and the Tandy CGP-115.[1][3] Tandy-plotter owners identify it as the ALPS DPG-1302 engine.[4]

Specifications

Atari 1020 specifications
Item Value
Text widths 20, 40 (default) and 80 columns[5]
Speed Averages 12 characters per second (Atari service manual); 10 cps in 40-column mode (FAQ)[2][1]
Colours Black, red, blue and green[1]
Graphics range X 0 to 480, Y −999 to 999[5]
Interface SIO at 19,200 bit/s[2]
Processors Two 6805-family microcontrollers with 4 MHz crystals[2]

The two speed figures come from different sources and are given as published.

Hardware

Atari's 1020 Color Printer Field Service Manual (FD100288 Rev. 01, August 1983) describes the electronics.[2] A serial-to-parallel microcontroller (A1, a 6805P) receives data from the computer at 19,200 bit/s and passes it to the printer controller (A2, a 6805V), which drives the print head and paper feed stepper motors through an LB1257 driver (A3) and switches the pen solenoid through transistors Q4 to Q7. Each microcontroller has its own 4 MHz crystal, X1 and X2.[2]

The pens lift and drop under an electromagnet: a pulse of about 5.4 ms in one direction pulls the pen down and a permanent magnet holds it there; the reverse pulse lets the actuator spring lift it. A reed switch and a magnet in the rotary pen holder find the home position for colour changes.[2] Atari's manual calls the pens ballpoint pens, and its parts list gives the standard pack as C061420-01 and the roll paper as C061533.[2]

The AC adaptor's output is rectified by D1 to D4 and regulated by two HA17805P regulators (A5 and A6), giving Vc, 5 V ±5 % for the motors and logic, and Vp, 5 V for the pen solenoid.[2] The FAQ lists the 1020 among the devices that use Atari's 9 V AC adaptors.[1]

Main parts (FD100288 parts list, p. 7-1)
Location Part Atari part number
A1 6805P, ROM version FC100346
A2 6805V, ROM version FC100347
A3 LB1257 octal power driver FC100348
A4 HD74LS09 FC100632
A5, A6 HA17805P +5 V regulator FC100350
D1-D4 V03C rectifier diode, 1.3 A FC100355
X1, X2 4 MHz crystal FC100357
– Print head motor unit (carriage) FC100370
– Paper feed motor unit (platen) FC100371
– Electromagnet assembly (solenoid) FC100375

Power-on test

Each time it is switched on, the 1020 moves its carriage, then draws a test pattern of four small squares, one in each colour. The pattern shows that the printer works and how much ink each pen has left.[2][5]

Known faults

  • Dried-out pens. Most original pens no longer write, and refilling them has a low success rate.[4][6]
  • Split nylon pinion gears on the carriage and paper feed motors, which stop the pen carriage or the paper moving accurately, even on unused printers.[7][4]
  • A dead oscillator on a microcontroller crystal, which leaves the printer lit but motionless.[8]

These are covered on the Atari 1020 Troubleshooting and Atari 1020 Maintenance Guide pages.

Documentation

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Michael D. Current (ed.), Atari 8-Bit Computers: Frequently Asked Questions, comp.sys.atari.8bit FAQ, last modified 29 November 2009: section 4.2 (the 1020, 1025, 1027 and 1029 printers), section 6.7 (power requirements) and section 11.1 (history, December 1982 to spring 1983). faqs.org. Community reference.
  2. ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 Atari, Inc., 1020 Color Printer Field Service Manual, FD100288 Rev. 01, August 1983. Theory of operation (pp. 1-1 to 1-12); testing (pp. 3-1 to 3-10); symptom checklist (p. 5-1); preventive maintenance and adjustments (pp. 6-1, 6-5 and 6-6); parts list (p. 7-1). Hosted here as File:Atari 1020 Color Printer Field Service Manual FD100288 Rev 01.pdf.
  3. ↑ 3.0 3.1 3.2 Wikipedia, "Atari 1020". en.wikipedia.org. Used for the paper width and the list of related plotters.
  4. ↑ 4.0 4.1 4.2 Tandy Tech wiki, "CGP-115", sections on the ALPS plotter engine, pens, gears and refilling pens (last edited 1 August 2026). tandy.wiki. Community reference.
  5. ↑ 5.0 5.1 5.2 Atari, Inc., The Atari 1020 Color Printer Owner's Guide (1982): controls, loading paper and pens, the power-on test pattern, and the text and graphics commands. Hosted here as File:Atari 1020 Color Printer Owner's Guide.pdf.
  6. ↑ drygol, "Atari 1020 Plotter – plotting pens replacement", retrohax.net, 2 February 2024. retrohax.net. Community repair write-up.
  7. ↑ Jason H. Moore, "Repair an Atari 1020 Printer (30-60 mins)", Atari Projects, 25 August 2018. atariprojects.org. Community repair write-up.
  8. ↑ RetroNerd, "Atari 1020 Colour Printer Plotter Repair", 7 January 2024. retronerd.co.uk. Community repair write-up.