# QSCad

# Questions And Answers

1. ### Why did you write it.?

   It seemed a good idea at the time. I wanted a new cad package so I and there were none I liked that ran under Linux. I was getting into TCL at the time so it looked like a good exercise.

2. ### Will it ever be fininshed.?

   No.Highly unlikely. I dont make as many PCBS as I used to so until I need to do something that the program won't do I probably wont update it.

3. ### How do I undo an operation?

   Redo from Start. I did not bother with an undo operation and yes it has really annoyed me at times.

4. ### Why do the colours reset when I reload the file?

   It is not a drawing package. If you want to draw in pretty colours use tkpaint. The one thing that other people will want is to change the colours to their preference. It would be a pain to have to change the colours in all the saved files.

   Colours are only used to give the designer a visual indication of what he is looking at.

5. ### Why don't the colours change when edit the configuration?

   The colours are loaded into each winfow from the defaults when it is created. When you edit the colours you are only editing the defaults. You must close the window and reopen it to see the changes. Changing colours is not something you will do often so it's no big deal.

6. ### How do I change the Key mappings?

   There is no WYSIWYG interface to the key bindings. Look in the file bindings.tk and it will fairly obvious what to change as all the key symbols are easily named.

7. ### How do I what keys do what?

   Press F1. The global keys are operative any time. The modal keys depend on what major mode has been selected. Select a mode (such as move) and then press F1. The model key will now reflect those that are defined for this mode. Take a look in bindings.tc and you will get an idea. Most of them are logical if not intuitive.

8. ### How do I make a net list from a schematic?

   Press Alt-N when no mode is active. This is used so infrequently I did not bother with a button for it.

9. ### How do I load a net-list into a pcb layout?

   Press Alt-N when no mode is active. Again you normally only do this at the start of a new PCB. If you load in another net you will get a new set of connected parts so you can use this for doing sub-circuits.

10. ### How do I do a 45degree track segment?

    You cant. For some reason I used the same layout for Tracks as connections. This removes redundant segments and also makes track laying much quicker. In the process all non right angles are removed. I thought I had changed to code to allow 45's but I didn't. It would be an easy change to treat tracks like lines and allow them to take any angle on the grid.

11. ### The text stays the same size when I zoom in and out, why?

    The base system TK canvas widget does not change the widths of lines and font sizes when the objects are scaled. In the Schematic Editor I always want to see the lines regardless of zoom setting. Sometimes it is a pain in PCB when you want to route a large board and have it all on the screen but you can't see where the track is going. The TK fonts do not support fractional font sizes so I did not bother to implement font scaling.

12. ### Why are some of the decals so large?

    The decals have been created by different people using different base scales. You can set the Scale to other than one before loading the decal or alternately you can just use the <and > keys to resize them.

13. ### Why do the decals resize when I alternate them?

    When you specify an alternate decal the decal is reloaded and thus reverts to the size it was created at. When you save them they are read back from the Schematic file. On the plus side if you much up a decal and find you need to replace it in the Schematic all you need to do is move it and alternate it until it switches to the one you want and it will automatically reconnect to existing connections providing you have the pins for them.

14. ### Why do connections stay when parts are deleted?

    Most deletions happen at the start of the design at this stage there are few connections so deleting them individually is easy. At the end of the design the deletions are normally done because are part needs to be replaced. In this case as I have not implemented a substitute part function, it is better to leave the connections and just reconnect them to the new part after the old one has been deleted.

15. ### Creating a new part decal is a real pain, why?

    I got all my decals from another package so I just created them with a tcl script. I havn't had to create new decals so I have not put much effort into the code for creating new ones. Sorry.

16. ### What is an anchor?

    Like tie dots an anchor allows connections to be attached to pins or pads on a part. The software could be recoded to not use them. For now place a anchor in the middle of each pad . By using an anchor point you can put this anywhere on the pad.

17. ### How do I turn off a layer?

    You can't. Because the screen is used as the database all objects must be present at all times. You could however change the layer colour to the background colour and get the same effect.

18. ### How do I get rid of the Tie Dots?

    You can't. They are needed to attach connections to other connections. Because the canvas is used as the database for the Schematic Editor there must be an object on the screen to hold the information. You can make them smaller in the configuration menu. Also you can uncheck them and not print them.

19. ### What is the flow chart for?

    Just to demonstrate that the program could have potential for other applications.

20. ### How do I change something that is not in the configuration menu?

    You will need to edit the source files. It's not that hard really. Look at the file globals.tcl and change the array defaults. Put any text that has spaces in it inside { and } or " characters.

21. ### Where do I find more help?

    See the online help from within the application.