Reverse engineering for Protel users

[Tepco]

Quick guide on reverse engineering for Protel users: You cannot import files from other programs, but, try this: Print PCB from original software in .ps format, any post script utility will work, i'm using Linotronix driver. Then import this .ps file into Corel Draw, and export as AutoCad version 2.5 .dxf file (later versions can be buggy). Now, import this into Protel, set as a mechanical layer, set origin, lock it (check if everything is on scale) and draw across it. Occasionally works with scanned or .bmp files. I made KROT pcb in less than 2 hours this way. Good old, now mature software still holds.

[Tepco]

Part 2: dealing with .jpg, .png, .bmp and others

Technically, it is possible to make PCB from any file format, even from picture. Scanned picture is recommended, but even camera shot can be used. Question is why, if PCB can be made from original file. In some cases file is poor quality, this way you can make your own file, change and modify, print, etc. This is easy shortcut to prevent making boards completely from scratch, here is the procedure:



In Corel11 package, one nice component is Corel Trace 11. Open original file with it, it won't be of proper board size, this will be fixed later. Convert image mode to B\W, change threshold from 128 if needed (in case of poor scan from magazine etc) to get completely B\W with no contrast. Now select Trace , usually By Centerline or By Sketch and observe results. May depend on quality of original, try default settings and play with them a bit until you get something reasonably looking. Then save trace results in .wmf format. From now, Corel Draw is used, open this file and you will see board size is radically different from what is needed.


Protel is raster based program, unable to resize anything, (you can change pad, track hole etc. size but not resize entire board ), and .dxf format is only one to communicate with other programs. So, vector based program like Corel is needed for resizing and format conversion. In Corel, set grid to 100mil and make it visible, select all, and use Arrange\transformation\size to first coarse, and then fine, step by step, tune board size, monitoring some characteristic point, like IC footprint, until it fits to 100mil grid as close as possible. Be careful, if you mess this step, later cannot be corrected. Then export file in AutoCad 2.5 .dxf.


In protel, first set grid to 100mil too (this is important!), select any, say, mechanical layer and import .dxf. Select all, set snap grid to small value, and move selection to get monitored part of board to 100 mil grid. Lock layer, change color if you want and you have template to draw your PCB over it.


For scanned or camera pictures, before all this, another step is needed, but this is more about picture manipulation, not board making. First open picture in Corel Photo paint, and manipulate color filters, then change to gray scale, manipulate gamma, brightness, contrast, then convert to B\W and save, must look as close as possible to BW scan or artwork. Similar with scanned boards from old magazines, bit easier with scanned BW board print.


If someone is interested, I can make bit more detailed description, with examples and actual screenshots. Also, if someone want to rip-off or redesign something, I can offer help and some expertise.


From tomorrow I will be off this forum for some time, KROT chips didn’t arrived yet, so will be continued.

[Tepco]

Final part: tool

Here it is, right from 1994, still in shape. Run PFW.exe, get familiar with it... Should work on any 32bit system, including Linux on Wine loader, for 64bit you need virtual machine.