Atari XDM121
| Atari XDM121 Letter-Quality Daisy-Wheel Printer | |
|---|---|
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| The XDM121 on the cover of Atari's owner's manual | |
| Manufacturer | Atari Corp.; built by Silver Seiko, Japan[1][2] |
| Type | Daisy-wheel impact printer |
| Release date | Announced January 1985; shipped summer 1987[2] |
| Discontinued | About mid-1988[1] |
| Price | US$159 (1988)[1] |
| Interface | Atari SIO, two sockets[2][3] |
| Compatible | Atari 400, 800, XL and XE computers[2] |
| Dimensions | 398 × 128 × 316 mm (W × H × D)[3] |
| Weight | 7 kg[3] |
| Power | Built-in supply; 55 W operating[3] |
The Atari XDM121 is a letter-quality daisy-wheel printer for the Atari 8-bit computers, styled to match the XE range. It prints fully formed characters from a 96-character print wheel at 12 characters per second and connects directly to the computer's SIO port, with a second SIO socket for daisy-chaining.[3][2] Atari announced it at the Winter CES in January 1985, "under $200", and shipped it in the summer of 1987.[2] It was the only daisy-wheel printer sold under the Atari name.[1]
History
[edit | edit source]The Atari Computermuseum says the XDM121 was made in Japan by Silver Seiko and based on its Silver Reed EXP-420, that it was on sale only briefly, from the third quarter of 1987 to about mid-1988, and that it cost US$159 in 1988. A version with a different interface, the SDM124, was not released.[1] The FAQ lists a pin-feed tractor, a single-sheet feeder and a 12-pitch print wheel as accessories, and asks whether any of them was released; the museum names the tractor as the Silver Reed CF100.[2][1]
Specifications
[edit | edit source]| Item | Value |
|---|---|
| Printing method | Daisy wheel, 96 characters |
| Speed | 12 characters per second |
| Direction | Bidirectional, logic-seeking; unidirectional by command |
| Pitch | 10 or 12 characters per inch, or programmable |
| Line length | 80 characters at 10 pitch, 96 at 12 pitch |
| Line feed | 1/6 inch, or programmable in steps of 1/48 inch; 2.5 inches per second |
| Paper | Friction feed, rear entry; up to 11.8 inches (300 mm) wide; original plus three carbon copies |
| Ribbon | Multistrike carbon-film cassette, about 190,000 characters |
| Interface | Atari 8-bit serial (SIO) |
| Power consumption | 55 W operating |
| Operating temperature | 5 to 35 °C |
The values are from Atari's manual.[3] Replacement ribbons listed by the FAQ are the Silver Reed CF130, Olivetti ET201 and ET221 and Nu-Kote NK136.[2]
Atari's manual lists 100, 120, 220 and 240 V AC power options. The FAQ says only the 120 V North American version was sold, with a current rating of 0.7 A, and that the other versions were planned but not released.[3][2]
Setting up
[edit | edit source]- Before switching on for the first time, remove the carriage packing, then rest the printer on its back panel and remove the two shipping screws and collars that hold the carriage for transport. Atari warns against switching on before this is done.
- Switch off every part of the computer system.
- Plug the SIO cable into the computer, or into another device such as a disk drive, and into either SIO socket on the printer.
- Plug the mains cord into the Power socket on the back panel, below the on/off switch, with the printer switched off.[3]
The XL and XE operating systems address the printer as P:, P1: or P8:; the 400 and 800 respond to P: and ignore any device number.[2] With the Atari XEP80 handler loaded, the XDM121 is P8:.[4]
DIP switches
[edit | edit source]Four DIP switches sit in a small blue box inside the front panel, behind the control panel. Only switches 1 and 2 are used, and all are off as delivered. Switch 1 on selects 12 pitch (off: 10 pitch); switch 2 on sets a 15-inch page for the single-sheet feeder (off: 11 inches). The printer reads them only at power-on or when told to return to its defaults.[3]
Self test
[edit | edit source]Hold down the Line Feed button while switching the printer on. It prints the whole character set of the daisy wheel repeatedly until switched off. Check the printout for even print quality and spacing; if it is uneven, check the ribbon and daisy wheel installation.[3]
Care and troubleshooting
[edit | edit source]| Symptom | Probable cause | Action |
|---|---|---|
| Printer does not respond | Power cord or SIO cable loose; printer off-line; two printers switched on together | Check the cords and that the Power light is on; press On Line; switch on only one printer at a time. |
| On Line light blinking, printer off-line | Ribbon used up or missing, paper out (with the feeders), or ribbon tangled in the daisy wheel | Replace or refit the ribbon, or untwist and reinstall it, then press On Line. |
| Light, smudged or spotty print | Ribbon cassette fitted wrongly or damaged | Refit or replace the cassette. |
| One character prints badly | Damaged type element on the daisy wheel | Inspect the wheel and replace it. |
| Paper jam | Paper loaded wrongly | Switch off, remove the paper and any torn pieces (tweezers help), reload with the paper-release lever in the friction-feed position. |
The table is condensed from Atari's manual.[3] Atari's routine care:[3]
- Keep the top cover closed to keep dust out of the daisy-wheel and carriage area.
- Clean the platen and paper-bail rollers now and then with a cotton ball lightly moistened with rubbing alcohol, turning the platen as you go.
- Do not touch the carriage rod or guide bar; finger grease collects dust that hinders the carriage.
- If anything falls into the print-head or carriage area, switch the printer off at once and remove it.
- Handle daisy wheels carefully and do not bend the spokes.
Warning: the XDM121's power supply is built in and runs from the mains.[2] Unplug the printer before opening the case.
Documentation
[edit | edit source]- Atari XDM121 Letter-Quality Daisy-Wheel Printer Owner's Manual, C026323 (1986), 87-page scan: setting up, ribbon and daisy wheel, paper, control panel, self test, AtariWriter and BASIC, DIP switches, control codes, troubleshooting, specifications. It has no circuit description or service information.
Related pages
[edit | edit source]References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Atari Computermuseum, "XE-Peripherie: Atari XDM121 Daisy Wheel Printer", atari-computermuseum.de (retrieved 2026-10-06), in German. Maker and original model, sales period, 1988 price, SDM124, tractor feeder.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 Michael D. Current (ed.), Atari 8-Bit Computers: Frequently Asked Questions, last modified 2 August 2026, mcurrent.name (retrieved 2026-10-06). Section 4.3 (the XDM121: print wheel, device numbers, connectivity, power, accessories, ribbons, manual) and the 1985 and 1987 chronology in section 11.1. Community reference.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 Atari Corp., Atari XDM121 Letter-Quality Daisy-Wheel Printer Owner's Manual, C026323, 1986. Chapter 1, pp. 3–19 (unpacking and shipping screws, connecting, ribbon, daisy wheel, paper, control panel, self test); chapter 3, pp. 29–30 (DIP switches); chapter 4, pp. 59–60 (troubleshooting and preventive maintenance); appendix D, pp. 77–78 (specifications). Hosted as File:Atari XDM121 Daisy-Wheel Printer Owner's Manual C026323.pdf.
- ↑ Atari Corporation, Atari XEP80 Interface Module Owner's Manual, C026416-0A1 Rev. A, 1987, p. 8 (printer port selection). Hosted as File:Atari XEP80 Interface Module Owner's Manual C026416.pdf.