pilgrim@daimi.aau.dk (Jakob G}rdsted) (01/25/91)
Before you read any further: This is just a silly idea I want to tell the world about! The Amiga has got a nice port in which one plugs the mouse, and most of the serious programs utilises this to move the pointer about. But (especially in Painting programs, but also elsewhere) a mouse is only one type of "userinterface", and it could be nice to use a drawing- pad (these thingies with a plate and a pencil you move around), but this would not be compatible with the mouse interface: The mouse works by sending pulses for vertical and horisontal movement. Using a drawing pad, you are able to lift the pen from the pad, and put it down elsewere on it; here your coordinates are absolute. How could the mouse's inter- face be adequate, to emulate lifting the pencil and putting it down else- were ? I always thought this was a bit impossible, but I have come up with an idea ( which the rest of the world probably have known since stone age): It requires the drawing pad to be "intelligent" i.e. have its own chips and therefore powering, hopefully from the joystick port(external powering is such a bad thing). I'm afraid it will be expensive, but here we go: The drawing pad of course keeps track of the pen's absolute coordinates. Whenever it is lifted, its coordinates are those it had when it left the surface. In fact the pad should not keep track of where the pen is, but of where the pad wants to tell the computer the pen is. This is quite like the "draw continous curve with brush"function in Deluxe Paint - when you move the mouse too fast, you see that the computer in fact draw straight lines between checkpoints. The pad should do the same. It should sample a checkpoint, then emulate the pulses the mouse would send to the computer if moving in a straight line to the new "destination", and when it had updated the computer, sample another checkpoint (i.e. read where the pen is), and do another emulation of the mouse, and so on.(this is why the board would need some chips, as I see it, it must be able to do quite a lot of arithmetics) The solution used right now, I think, is a software interface that does the same thing(?) and works with most "wellwritten" programs like DeluxePaint and such. A problem with this hardware solution is, that there will be a problem with the alignment between the screen and the board. This could be solved by a reset button on the board, allowing one to adjust it any time. (you hold down the button, and you are free to move the pen around. When you let go of the button, the cursor has Not moved). Just a thought
peterk@cbmger.UUCP (Peter Kittel GERMANY) (01/28/91)
In article <1991Jan25.095710.6716@daimi.aau.dk> pilgrim@daimi.aau.dk (Jakob G}rdsted) writes: >Before you read any further: This is just a silly idea I want to tell the >world about! Don't be afraid, not silly. > The Amiga has got a nice port in which one plugs the mouse, and most >of the serious programs utilises this to move the pointer about. But >(especially in Painting programs, but also elsewhere) a mouse is only >one type of "userinterface", and it could be nice to use a drawing- >pad (these thingies with a plate and a pencil you move around), but >this would not be compatible with the mouse interface: The mouse works >by sending pulses for vertical and horisontal movement. Using a drawing >pad, you are able to lift the pen from the pad, and put it down elsewere >on it; here your coordinates are absolute. Well, normally you are supposed to use the mouse button(s) to indicate the pen status. > The drawing pad of course keeps track of the pen's absolute coordinates. >Whenever it is lifted, its coordinates are those it had when it left the >surface. In fact the pad should not keep track of where the pen is, but of >where the pad wants to tell the computer the pen is. This is quite like >the "draw continous curve with brush"function in Deluxe Paint - when >you move the mouse too fast, you see that the computer in fact draw >straight lines between checkpoints. The pad should do the same. It should >sample a checkpoint, then emulate the pulses the mouse would send to >the computer if moving in a straight line to the new "destination", and >when it had updated the computer, sample another checkpoint > (i.e. read where the pen is), and do another emulation of the mouse, >and so on.(this is why the board would need some chips, as I see it, it >must be able to do quite a lot of arithmetics) I only know about a commercial product, the "Easyl" graphics tablet. This is a high resolution graphics pad for use in CAD and similar. It comes with drivers that translate the board coordinates to mouse moves. And it has two buttons that you trigger with your other hand. Together you can use DPaint quite normally. And recently there was a discussion here how to connect a Koala pad from the C64 to the Amiga. As far as I remember they said it could be done, but nobody gave the real pinout or a listing of the needed driver (because this would connect to the analog pot inputs and not to the impulse-driven mouse inputs). -- Best regards, Dr. Peter Kittel // E-Mail to \\ Only my personal opinions... Commodore Frankfurt, Germany \X/ {uunet|pyramid|rutgers}!cbmvax!cbmger!peterk
peck@ral.rpi.edu (Joseph Peck) (01/30/91)
In article <793@cbmger.UUCP> peterk@cbmger.UUCP (Peter Kittel GERMANY) writes: >In article <1991Jan25.095710.6716@daimi.aau.dk> pilgrim@daimi.aau.dk (Jakob G}rdsted) writes: >>Before you read any further: This is just a silly idea I want to tell the >>world about! [...] >And recently there was a discussion here how to connect a Koala pad >from the C64 to the Amiga. As far as I remember they said it could >be done, but nobody gave the real pinout or a listing of the needed >driver (because this would connect to the analog pot inputs and not >to the impulse-driven mouse inputs). Well, I just received the schematics and a little software hack from Jeff Lavin yesterday. As soon as I make a little correction to the schematic (Jeff, you labelled both the resistor and the potentiometer to be changed as R1, instead of R1 and R37. Or something like that, I am typing this from memory.) I will lharc it, and ftp it to abcfd20. I intend on uploading it as koala64.lzh. This is because I took apart my atari version, and ummmm, it looks nothing like the schematic that jeff sent me :( This schematic is for the Commodore 64 version, model 2. I did try the accompanying software, and it seemed to behave properly. But, it is hard to say for sure, since the pad is set for a different sampling rate. I plan on swapping resistors in mine until it works..... I will post another message once I have actually ftp'ed it to abcfd20. Oh yeah, I have never done this before, so be patient if my first attempt mangles the file :) Joe Peck peck@ral.rpi.edu