Linux 6.10 Shows People Are Still Using USB To Parallel Port Adapters In 2024

[Daktyl198]

I use USB to Serial/Parallel adapters all the time at work. Industrial machines often don't talk "modern" standards. Hell, some of them are 40 years old.

[Drizzt321]

From what I understood, pretty much all of these USB-to-Centronics adapters only support higher level printer and scanner functionality, and do not support bit banging. So driving CNC machines or sound devices such as the Covox Speech Thing is not possible with these things. I know that those are very niche applications, but industrial users and hobbyists that require the full functionality of an actual IEEE 1284 parallel port won't be able to use these solutions.

I believe someone developed an adapter once that would support bit banging, but I'm not sure.

Probably could create an RP2040 based USB serial to Parallel bit-banging adapter.

[szymon_g]

Never really thought about it because I dont use a phone for "productive" work, but its a very fair point! 2 USB ports on the phone would make a ton of sense!

Q10 blackberry had mini hdmi and USB port on it... Totally useless feature

[timofonic]

Half right/half wrong answer. USB to Electronics cannot be used to drive direct control CNC machines or Covox Speech its not bit banging limitation Both of these require very tight timings. Yes you can bit bang on them but latency for bit changing is the problem., The translation from USB data stream to data pin of the parallel port takes time that you don't have for correct operation of direct control CNC or Covox Speech.

Please note I said direct control CNC machines. Indirect control CNC machines some of those you basically print the gcode to the controller. Why parallel instead of serial back in the day for the indirect control CNC is the speed of transfer with the old parallel port being 2 megabytes per second vs your old RS232 that caps out at 350kbps.

Do note that 2 megabytes per second that is 16 mbps yes faster than your early 10mbps networking. Reality indirect control CNC machines connected by parallel ports are basically over grown printers.

Oh, yes. You're right! Excuse me, I forgot it, sorry.

What about this one? It supports up to 1 Mbps.

And this one? (NC200)?

What about this one for PCIe to two parallel ports?

[c117152]

Good to hear the Sophgo RISC-V SoCs mainlining is going well. The Milk-V Oasis (SG2380) targeting the desktop will make or break over their kernel support so it's encouraging to see there's traffic going.

[oiaohm]

Oh, yes. You're right! Excuse me, I forgot it, sorry.

This is you not knowing the tech and how it de-evolved.

And this one? (NC200)?

"ARM motion control chip" That one is not direct control CNC machine controller. That is in fact a indirect control. The direct timings of motor control is done on the controller board. This is where it come is this direct or indirect control. indirect control with CNC does work over USB. Not all parallel connected CNC controllers are direct control.

What about this one for PCIe to two parallel ports?

Startech notes the following

Data transfer rate up to 1.5 Mbps

Those ports are slow but this did not happen instantly.

https://www.okahama.com/product/pci-parallel-1-port/

with support for data transfer speeds of up to 1.8Mbps.

Here a PCI card faster than a PCIe.

The VESA Local Bus connected parallel port is 2 megabytes per second that is 16 mbps parallel port.

ISA parallel port also could get up to 2 megabytes per second that is 16 mbps.

This is one of the cases newer is not better. Your current day printer ports are 10x slower than what they use to be.

timofonic this is one of biggest problems you run into attempt to run old direct control CNC that are parallel connected is that modern day parallel ports are total garbage because they cannot run at the 2 megabytes per second the old direct control CNC require to work correctly.

Yes the old IBM TX parallel port need to circuit board work to make it do 2 megabytes per second but those modifications were done for CNC usage.

Max speed of a parallel port is the 2 megabytes per second or 16 mbps . Buying a new parallel port you can connect by PCIe or PCI or USB that can in fact do max parallel port speed is impossible.

Remember lots of your direct control CNC machines are 486 and before based with Vesa Local Bus and ISA. Yes when these systems break is not plug in a new computer it redo the control system and new computer because plugin in a new computer you cannot drive it correctly.

The problem is not bit banging the problem is conversion latency. There was bugger all conversion in the 8088-486 for these parallel communication things so it was possible to drive the ports faster.

[CommunityMember]

One of the companies I work for has label printers some of which still have parallel ports. As long as the printers keep going we haven't replaced them with newer models which are USB only.

Commercial/industrial facilities change slowly, and label (often thermal label) printers work for years if not closer to a decade. The primary consumable is the label (you do need to clean/wipe the thermal print head and clean out the grim that accumulates every so often), but they can just last. Parallel and/or serial was the standard (often only) interface when many of those printers were originally purchased. I regularly see Zebra thermal printers (to print labels for shelves for the merchandise) with parallel interfaces using an adapter in use by associates in big box stores.

[ResponseWriter]

I use one of these with an old laser printer. I had far more issues with a modern USB-only inkjet and went back to this so I'm glad these adapters are still supported.

[cthart]

Commercial/industrial facilities change slowly, and label (often thermal label) printers work for years if not closer to a decade. The primary consumable is the label (you do need to clean/wipe the thermal print head and clean out the grim that accumulates every so often), but they can just last. Parallel and/or serial was the standard (often only) interface when many of those printers were originally purchased. I regularly see Zebra thermal printers (to print labels for shelves for the merchandise) with parallel interfaces using an adapter in use by associates in big box stores.

Zebra printers are exactly the ones we’re using. Some sites are quite low volume and the printers are indeed a decade or more old. Yes, all sites have more than one so there’s no real problem with using old equipment until it dies.

[elbar]

If it would be easy to ditch parallel port for serial port(today standard also in industry version) and serial port would be more common on boards(it is but more spread with VGA mandatory ditch) and VGA and parallel port would be history.

Serial port has purpose for easy programming but its speed could be sometimes problem for some usages but should be easy switch if applicable for a lot of printers and also industry devices which today is more serial port oriented. USB weirdness to have still some(:-) USB2 mouses when only 1 or 2 USB-C port available and therefore none USB-C mouses present(maybe :-). Problem with USB instead of serial port is tough debugging and programming in favor for serial port. Look for USB debugging hardware with special prices up to 20k USD as price surprise shock

And TB port missing on boards and mandatory TB in graphic displays for designers(and kids) with pen is another story for nightmares in Dooooooooom :-)