Buying or making graphics tablet

[AmigaBruno]

I've recently been doing graphics on my Amiga A500 with Deluxe Paint III, like I did years ago. I also plan to get a copy of Photon Paint soon, especially as I started with Photon Paint.

Of course, it would be much easier and quicker if I had a compatible graphics tablet, but finding one nowadays would be difficult, which has even made me consider trying to make one at some stage in the future.

I think it makes sense to assume that any such tablet would be plugged into the mouse/joystick port, because the software already expects input from that port.

I think I've read that the Wacom KT-0405-A KT0405A ArtPad 2 II 5" Graphics Tablet is compatible, but that uses the serial port. Looking on eBay, there are a few, but mainly for parts or not working and postage on these from the USA to the UK is high.

The Atari 8 bit graphics tablet plugs into a joystick port and I read that the Atari reads it as a pair of paddles. I think this may be compatible, but I'm not sure how paddles are different to joysticks.

Another tablet I remember from years ago is the Koala pad, which was compatible with various computers, but I'm not sure if it requires its own software.

I hope people will be able to advise me on this. It could be an interesting electronics project for me at some stage in the future. Meanwhile, I'll continue to to graphics more slowly with the mouse.

[Ral-Clan]

Yes, I'm using an ArtPad II.  It used to be connected to my Amiga 2000 and it worked (no pressure though, but I was fine with that).  I was using a free driver off aminet.

I haven't tried to attach it to my A500 yet.  When I switched from big-box Amigas to WinUAE for graphics work (much faster CPU for graphics processing) I moved the Wacom tablet to the PC, where it worked as well (with its own drivers).

There were native graphics tablets for Amiga, but they are hard to find.

As for the Koala Pad, it's too low-resolution for Amiga graphics (i.e. it has a number of X and Y sensors which are under the resolution of most Amiga screens.  Also, I don't thing anyone ever wrote a driver for it to run on Amiga.  Lastly, it's not great at finely sensing where your pen is - okay for coarse stuff (i.e. VIC-20, C64) but I doubt for Amiga.

PS: when I bought my ArtPad II off eBay I remember it was quite cheap, being the old serial kind, and it was brand new in a box, shrink-wrapped.

[AmigaBruno]

Yes, I'm using an ArtPad II.  It used to be connected to my Amiga 2000 and it worked (no pressure though, but I was fine with that).  I was using a free driver off aminet.

I haven't tried to attach it to my A500 yet.  When I switched from big-box Amigas to WinUAE for graphics work (much faster CPU for graphics processing) I moved the Wacom tablet to the PC, where it worked as well (with its own drivers).

There were native graphics tablets for Amiga, but they are hard to find.

As for the Koala Pad, it's too low-resolution for Amiga graphics (i.e. it has a number of X and Y sensors which are under the resolution of most Amiga screens.  Also, I don't thing anyone ever wrote a driver for it to run on Amiga.  Lastly, it's not great at finely sensing where your pen is - okay for coarse stuff (i.e. VIC-20, C64) but I doubt for Amiga.

PS: when I bought my ArtPad II off eBay I remember it was quite cheap, being the old serial kind, and it was brand new in a box, shrink-wrapped.

So, that confirms the Artpad II works with the Amiga. I don't know what the pressure would be used for.

You seem to know a bit about the Koala Pad, as you say it has a number of X and Y sensors. What do these sensors consist of?

I remember from using the Amiga years ago that it was the normal thing to just plug in any peripheral and it worked without a driver. It seemed that only printers required drivers, but on the PC drivers were always required. Why would a graphics tablet require a driver for use on the Amiga?

[rvo_nl]

pressure is used to determine the thickness of your brush. the harder you press, the thicker the line. this works very natural and something I wouldnt do without. (I have an a4 size tablet for my pc)

[AmigaBruno]

pressure is used to determine the thickness of your brush. the harder you press, the thicker the line. this works very natural and something I wouldnt do without. (I have an a4 size tablet for my pc)

I see. Well, I'm only talking about Deluxe Paint and Photon Paint. In Deluxe Paint and from what I remember Photon Paint as well, you select the brush thickness from an on screen menu. Just because the input device is different won't change that.

I'm now reading this site about making a graphics tablet to get the general principles http://www.bongofish.co.uk/wacom/wacom_pt1.html .

[JimS]

You seem to know a bit about the Koala Pad, as you say it has a number of X and Y sensors. What do these sensors consist of?

The Koala Pad acts as if it was a pair of variable resistors one in each direction. So when you touch the pad, there's an x and y resistance that corresponds to the point you touch. The paddle hardware in the computer reads that out as a pair of values. I'm more familiar with the Atari 8-bit machines. The paddles read from 0-255 which was greater than the screen resolution in color mode.
It makes me wonder though... the resolution limit was mainly a result of the computer. If you used a a/d converter with more resolution, say 10 bits, could you get more meaningful resolution out of the Koala Pad? It's still a rather small drawing area though.

[bbond007]

Maybe if you could find the serial protocol for one of the tablets supported on the Amiga you emulate it using an android tablet (with usb serial port converter)

for an Amiga 1200 or something with TCP/IP you could go wireless and forget about serial...

[AmigaBruno]

The Koala Pad acts as if it was a pair of variable resistors one in each direction. So when you touch the pad, there's an x and y resistance that corresponds to the point you touch. The paddle hardware in the computer reads that out as a pair of values. I'm more familiar with the Atari 8-bit machines. The paddles read from 0-255 which was greater than the screen resolution in color mode.
It makes me wonder though... the resolution limit was mainly a result of the computer. If you used a a/d converter with more resolution, say 10 bits, could you get more meaningful resolution out of the Koala Pad? It's still a rather small drawing area though.

This sounds great! I don't understand it all at the moment, because I need to study some more about electronics, but I think this will put me on the right track.

[Ral-Clan]

This sounds great! I don't understand it all at the moment, because I need to study some more about electronics, but I think this will put me on the right track.

Essentially the Koala Pad was exactly like having a pair of rotary game paddles hooked up to the joystick input on your C64 or VIC-20. In fact, if you hooked paddle controllers to any program that used the Koala Pad, you could "draw" in a manner of speaking (like an etch-a-sketch).  One paddle would provide the X co-ordinate, the other the Y co-ordinate.

The Koala Pad returned an analogue resistance value to the input on the joystick port.  This was sampled by the VIC(?) chip on the VIC 20, and (maybe) the SID chip on the C64 to convert it to a digital value it would report to the program.

I'm not sure if the Amiga can do analogue to digital conversions on the joystick ports.  I've never seen paddle controllers used on a an Amiga.

It's certainly possible to hook a Koala to an Amiga if you have the knowledge of how to do analogue to digital sampling on one of the Amiga's ports.

And Deluxe Paint and some other programs did in fact have pressure sensitivity (from some of the Amiga specific tablets) if you had a tablet that was specifically supported by Deluxe Paint ---- I think the tablet for the Amiga was called SummaSketch or perhaps that was the name of the company.

As for the Amiga's lack of drivers vs. PC....well....you still needed drivers on the Amiga side, it was just that the hardware could be recognized by the Amiga without setting IRCs and figuring out hardware conflicts, etc.

You can't just plug a graphics card into an Amiga, for instance, without installing RTG software (which is essentially a driver).

[stefcep2]

Amazon has them:

http://www.amazon.com/Art-Pad-II-Graphics-Erasing/dp/B001IQ3XF4

[Ral-Clan]

Amazon has them:

http://www.amazon.com/Art-Pad-II-Graphics-Erasing/dp/B001IQ3XF4

That's about what I paid on eBay.

[CodePoet]

I could be wrong, but building an interface between modern tablets and an Amiga doesn't sound /too/ difficult. Are there any current drivers on the Amiga that allow you to use analog paddles in place of a mouse? If so, the absolute-positioning thing is solved. Most cheap active USB tablets are HID compliant (ie: Aiptek), Microchip have some small microcontrollers with USB capability and 12bit ADC, as well as example HID libraries for a few dollars.

Couple that with a couple of I2C/SPI ~500K Digital Potentiometers, and you should be able to throw together a HID to "Analog" converter, which will crap out an X/Y resistance value for an X/Y position on the tablet. I'd have no idea how to action pressure sensitivity though, as I believe the Amiga only has two Analog inputs per port.

I guess if you wanted to sacrifice absolute positioning and opt for relative positioning (like a mouse) to gain pressure sensitivity, you could use the V/H/VQ/HQ pulse inputs to move the cursor, and use the paddle input for pen pressure

...Of course this all assumes an off-the-shelf driver/application exists for this type of behaviour

[JimS]

I'm not sure if the Amiga can do analogue to digital conversions on the joystick ports.  I've never seen paddle controllers used on a an Amiga.

The hardware is there to read analog resistance on the Amiga's joystick ports. I've never seen anyone use it either.... although I think some of the 3-button mice used the analog inputs as the 3rd button.... after all, a button is just a variable resistor with only 2 values... 0 and infinity. ;-)

[AmigaBruno]

I thought I should let everyone know that after all this time, I've recently managed to buy a classic Amiga graphics tablet from eBay, which has arrived today, Wednesday, October 28. This tablet is called a "Tabby" by Micrograf, with installation software by Datel. I'll let you know how I get on with it. I think this will greatly accelerate my production of artwork, as well as improve the quality of the artwork. I hope to transfer and upload some artwork I've already done quite soon, possibly on a dedicated website. I have found out how to transfer files between my Amiga A1200 CF card hard drive and a PC hard drive using WinUAE, but this doesn't seem to work under Linux with FS-UAE.

[Niding]

Ive found using PCMCIA port with CF card to be a very nice way of transfering files.
No need for WinUAE, just open windows from CF card directly in Windows.
Need a CF card reader on the PC too, but I guess you already got that.

http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=42&products_id=440