DOS ain't dead

Okidada 120 Printer: Will it work with MS-DOS? (Users)

posted by dave_mason, 23.10.2017, 01:50

PCs have three different serial connectors. RS-232 and USB are serial, but incompatible with the Commodure/Oki implementation because they don't include separate clock signals, whereas the Oki/Commodore connection has a clock signal line to synchronize with the data stream. Also, RS-232 signals go negative with respect to ground, whereas the Commodore's were most likely TTL level (zero to +5 volts or thereabout, never negative-going). Signal levels can be converted, but the lack of a clock line is probably fatal.

The other serial connection standard on PCs is PS/2 mouse/keyboards, or the larger AT keyboard connector. These do have clock signals, but originating from the peripheral devices, whereas the Oki most likely expects the clock to come from the Commodore. Also, the Commodore has two signal lines in addition to data, whereas PS/2 didn't have signal lines other than the data itself. The pinouts are different, so at a minimum you would need to kludge an electrical interface to accommodate that, and you would need to be able to intercept data from the PS/2 controller before it got interpreted as keyboard or mouse input. Whether the PS/2 lack of control lines is fatal or not is an unknown to be dealt with.

This could turn into a regular briar patch of a project. My Plan B suggestion would be to sell the Oki to a Commodore fan, or arrange a swap since Commodore-compatible printers must be a lot rarer than DOS-compatibles.

Complete thread:

• Okidada 120 Printer: Will it work with MS-DOS? - CluelessInSeattl, 18.04.2017, 20:00
  • Okidada 120 Printer: Will it work with MS-DOS? - glennmcc, 19.04.2017, 22:57
    • Okidada 120 Printer: Will it work with MS-DOS? - CluelessInSeattl, 20.04.2017, 02:34
  • Okidada 120 Printer: Will it work with MS-DOS? - dave_mason, 23.10.2017, 01:50