DOS ain't dead

> After a long hiatus I'm starting to play around with my old MS-DOS
> computers again and having a lot of fun with them. So I'm hunting around
> for a printer to hook up to my DOS system. On eBay I found an affordable
> dot matrix printer, but the name of it -- Okidata 120 For Commodore
> Computers -- makes me wonder if it would even work with MS-DOS.
>
> Also, it uses a serial cable to connect to the computers. I can't recall
> ever having a had printer that used a serial cable, not even in my CP/M
> days:
>
> So, does anyone here know if I would be able to get this printer to work
> well with MS-DOS?


Sorry... no idea one way or the other.

I can think of 2 ways for you find out tho.

1) Try printing to it in DOS.

2) RTFM

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.