Connecting desktop cnc with parallel interface to my laptop

Early in this year I bought cheap chinese desktop cnc engraver for about $800, good and easy to operate, except for one problem. When I purchased it I didn't noticed that It has parallel interface for computer operation, but my laptop don't has any parallel port. It has only USB port. My desktop PC has parallel port but It was to old and slow.

I searched web for solution to connect my cnc to laptop and found that it is not easy.
First, USB is for serial communication and it can't communicate with parallel device. some electronic device is available for data conversion between serial and parallel devices. It is called shift register. 74HC595 is one of that kind of chips and you can get information from here. Unfortunately, I am not electronics expert, I am software developer. So making some data converter using this chip will be difficult job.
Another problem is, popular desktop cnc softwares also talk to parallel ports not usb. So if I succeed to connect my cnc to laptop, it will still be problem that no suiltable software exist.

Someone tried to solve this situation. they made home brew device to convert usb data to parallel data. If you are interested, check it out here.

Some guys made mach3 usb - parallel interface which is called PLCM-LPT2. You can check it out here. another team has released UC-100 which is very simillar to PLCM-LPT2. Find out it here. These products are commercial product and maybe they will operate perfectly. One disadvantage - theses products support only one cnc software, MACH3. Their divers are supplied as mach3 plugin form. so you decide to use another cnc software, they will do no good.

I spent lot of time to find a way to solve my problem. It looked very simple to solve, but as time goes by, It gets harder. And I found that I was not alone. Many people faced the same situation and found nothing useful.

And then, a miracle happened. I heard someone used arduino board for parellel - serial conversion. It was simple and handy.  He made it for jedicut but I think it can be extended to another software.

Another one is arduino g-code interpreter for reprap 3D printer project. You can google so many arduino based cnc interface board. Arduino is good because it doesn't require heavy knowledge about software or electronics. It is very simple to develop and price is not expensive. You can buy it easily via internet.

I want use my cnc engraver easily with laptop. So I decide to make my own version of arduino serial - parallel convertor.

Above, a parallel cable is connected to cnc engraver and a usb cable is connected to laptop. I don't have db25 female connector, so I had to wire it using hand wrapping tool.

It worked as I expected. It receives data from laptop via usb cable. It recognizes only six command 1,2 for x axis movement, 3,4 for y axis, 5,6 for z axis.

I can write g-code interpreter for arduino, but it will be waste of time because someone else already released good program. I made g-code interpreter on laptop. It interprets g-code and send six command(1,2,3,4,5,6) to ardunio. It just fits my need.

Currently only three g code supported. f, g0, g1. It may be enough for common operation. For example, py-cam g-code output is mainly made of above 3 commands in 2d engraving, so I was enable to use py-com g-code to my laptop software without modifying it. Another command can be implemented easily, but I am currently busy so I have no time to improve my project. I want share this project someday, but unfortunately, my program source is commented with Korean letters, most of them may not be readable.