Need some help from the #RetroComputing community: you all know the USB-to-serial adapters that allow connecting an old device with a serial DB9 port to a more modern PC with USB. Now, I need an adapter that does it the other way around. I have a digitizer with USB (type B) and want to connect it to an old PC that only has serial. Anyone aware of such adapters? Google is sadly of no help, as it does not understand the subtile difference between the two...
@derSammler I've never heard of such a thing myself. For naive intentions, I don't think that'd even be physically possible... even over low speed, USB's rate is 1.5Mbaud, well over the maximum rate of RS-232's 115kbaud.
If some other device like a rsspberry pi or arduino handled negotiation and flow control, it'd be theoretically possible to send only the relevant messages over its UART in a way that's compatible with existing digitizer drivers, but that's a lot of bespoke work
Is there no way to fit the computer with a USB expansion card?
@derSammler I've found a USB host board that has instructions on how to decode a serial stream from the device and send it back over the UART. This unfortunately looks like it'll take some time and technical knowhow to implement, but it may be viable for your use case. https://www.hobbytronics.co.uk/product/host-board
@elfi Looks interesting. 🙂 Might be a starting point if nothing else comes up. Thanks.
@derSammler reviewing the thread from a browser, it does look a fair bit easier, but would still likely require a microcontroller that can negotiate with the device if there isn't a solution already. I'll see what I can find