MPS-801 printer
The Commodore MPS-801 is a dot matrix Printer from Commodore released in 1984. MPS stands for Matrix Printer System.
The Commodore MPS-801 was one of the first Printers offered by Commodore for its home computers. The printer used fan-fold paper via a paper tractor. The print resolution was a 6×7 Matrix at 10 chars/inch. The printing speed was about 50 chars per second.
Because of its 7-pin print head, character descenders couldn't be created. The printer only supports unidirectional printing, as it is only printing when the print head moves from left to right. This made the printer very slow, compared to later models. The interface to the computer was a serial IEEE-488, the serial bus for the Commodore VIC-20.
The printer was not developed and produced by Commodore. The MPS-801 was an OEM product, originally made by the Japanese company Seikosha, a subsidiary of the clock manufacturer Seiko, and one of the largest printer manufacturers in the world. The corresponding Seikosha model was the GP-500 VC.
For manual paper-handling there was a mechanical handwheel on the right side of the printer. Additionally, a membrane key was provided for incremental linefeed.
Apart from the complete ASCII-charset, the MPS-801 could also print all Commodore graphic characters and reverse characters were possible. In addition to text and special glyphs, the printer was capable of printing graphics. These units have the most unusal printing mechanism ever made, the so-called "Uni-Hammer" system manufactured by Seikosha. Unlike in conventional dot matrix printer, where multiple pins strike a stationary roller, the Uni-Hammer is a single printhead that strikes a rotating ribbed drum behind the paper, hitting the paper to make a single dot at a time. Hence each dot is produced individually, whereas normal dot printers use a multi wire printhead and create 8 or 9 dots at a time banging against a fixed platen.
Being a rebranded Seikosha GP-500 VC printer, finding new ribbons for the MPS-801 is quite easy. Moreover, the ink tank can be carefully opened and manually refilled with fresh ink.
Technical Data
- Print method: matrix print ("Uni-Hammer" system)
- Dot matrix: 6×7-Dots
- Character height: 2.82 mm
- Row length: max. 80 Columns
- Row distance: 6 Z/inch in char mode, 9 Z/inch in graphics mode (1 inch = 2.54 cm)
- Print speed: 50 chars/sec.
- Print method: unidirectional print
- Paper transport: tractor
- Ink-ribbon type: 2-parts cassette with exchangeable ink reservoir
- Paper width: 4.5 to 8 inch
- Copies/carbon copies: original + 2 carbon copies
- Graphics: dot-matrix, 7 vertical dots/column
- Weight: approx. 4,8 kg
Links
- MPS-801 Printer User's Manual User's manual (pdf)
- MPS-801 Printer Manual User's manual (txt)
- Service man 1985 Service manual (pdf)
