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Old computers and devices have no USB support so they can only output via LPT or serial port. New printers are either wireless or use USB, and require a computer to translate the data coming from old computers. As such if you have many old computers and want to use something like a label printer just for text or simple graphics, you are out of luck, without going through a lot of jumps

Of course the easiest solution is to save the file(s) to print and move them to a modern machine, but that would involve many jumps to save the output from the old devices, and in some cases you only have output as serial port or a floppy disk.

Possible Solutions explored:

  • LPT to USB: to connect directly a USB printer to LPT. Problem is that these devices are not that common at all, and even if you find one, it will work only with certain printers.
  • Print Server: Connect the printer to a Windows/Mac/Linux machine and receive print data to it. Problem is that you need a way to send this data from old computers that have only serial or parallel port.

I am trying to solve the problem and have something that can interface with any printer; like a small RPI Nano or Pi or other small boards, so the system can be easy to set up, but I had no luck finding such project. Is there a best way to achieve this, that does not require multiple solutions chained together, that would allow something like an old DOS machine or portable PDAs to print out to a usb/Bluetooth/WiFi printer?

The ideal would be something self contained; but if the only way to achieve this is to have something that required the printer to be attached to a computer 24/7, that is okay too.

Giacomo1968
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rataplan
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4 Answers4

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If you just want a label printer, buy a new RS232/DB9 serial label printer.

For example

https://www.alibaba.com/product-detail/Multiple-Interfaces-USB-RS232-Ethernet-80mm_1600071188275.html

or https://www.alibaba.com/product-detail/YHDAA-High-Speed-Printing-Usb-Lan_1601221989390.html

Point Of Sale computers are still (2025) sold with RS232/DB9 ports, to connect to a cash drawer or receipt printer, and cash drawers and receipt printers are still sold to use with existing Point Of Sale equipment.

Most of these printers are fairly generic (due to the open-source nature of typical Chinese electronics), but you have to send control codes, and may have to send bit-map images.

user165568
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Not mentioned so far. I always use network printers. Not Wifi but wired.

  • If you have wired ethernet to your computer then go this way.
  • If you only have Wifi, then look for Wifi enabled printers.

Some printers will do both of the above (as well as USB).

Rohit Gupta
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I've not tried it, but you should be able to convert a serial connection (RS232) to a USB connection PROVIDED YOU GET THE RIGHT TYPE (ie you want USB host mode).

Googling "rs232 to USB host" came up with some clues and I found a product that claims to do what you are after, but its not cheap.

 https://microcontrollershop.com/product_info.php?products_id=5031 -

Doing a further search "SER2USB" revealed some other sources for the same device -

 https://www.digikey.com/en/products/detail/ak-nord-gmbh/SER2USB/7621809
 https://www.ak-nord.de/product-75.html?language=en

Less well defined specs/statements but theoretically this should work to convert RS232 to Ethernet a lot more cheaply.

https://www.aliexpress.com/item/1005006252276846.html

Then, if you need anything more complex then plain text, you need to solve the driver issue...

You have not advised us what the old computers are. I do wonder if it would be easier and cheaper to get some kind of add-on card for them to give them an ethernet or USB output - and of-course you need something modern enough that it will run a tcp/ip stack - so I imagine things older then a 386 could be ruled out.

I do wonder if you could alternatively purchase a cheap FTDI to USB interface (they are ubiquitous and cheap) and then run a cross-over connection to a device like a Raspberry Pi - then turning this into a software problem (how big the software problem might again depend on your PC. I'm thinking along the lines of making it talk TCP/IP over a PPP connection - which again assumes your computer is capable of driving a PPP connection - so Windows 3.1 or thereabout. Alternatively you could probably futz arround with a terminal emulator and redirect this to a port using Netcat or similar.

davidgo
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As you gave only vague information, we can give only general principles for an answer. Here are the general principles that apply here:

You need a common connection, or a chain of connections (basically, an adapter, a series of adapters, or adapting devices) between the different devices.

A common connection is going to be the simplest and most reliable method and should be your primary goal.

If your computer truly lacks a network port, you should open it up to see if there's a connection point inside it, such as a PCI slot, that allows you to install a common compatible connection.

If you have exhausted the possible options to achieve a common connection, your final option is to adapt between the devices. Adapters are notoriously finicky, and have odd, undocumented, and unexpected compatibility issues, which is why they are a distant second choice and should only be tried if a common connection cannot be achieved. But the basics are simple: find an adapter or adapters that result in a connection between the devices.

music2myear
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