C64 DTV <-> PC transfer cable built. First?

[tlr]

adric22 said:

full user-port in the DTv2? Doesn't the hummer game sold by radio shack have a version 2 board inside? Does anybody know if it has user-port available?

I'm sure that the DTV V2 does not use the same board as the hummer game from the pictures I have seen here. It seems to contain similar memory components, but you couldn't count on the same connections being available.

adric22 said:

Also.. since you are working on some transfer software, I guess you've gotten the joy-port to work for that. So is there any good way to use the joystick port for input and output and still be able to use the keyboard too? won't the keyboard scan routine send eroneous data to whatever devices you have connected?

I don't need to use the keyboard during the transfer, so it's no problem. I do not know of a way to use the Joystick pins for I/O without interfering with keyboard operations. Only 5 of the lines of each CIA port is used for the joysticks, so you can use parts of the keyboard though. You'll have to check the key matrix to see which ones.

[Wildstar]

Any idea of outputting data across the IEC? That is another alternative. If you go into this much trouble, would IEC port do as well?

[tlr]

wildstar said:

Any idea of outputting data across the IEC? That is another alternative. If you go into this much trouble, would IEC port do as well?

Sure, but it has fewer I/O lines, so you couldn't transfer as fast. Besides if you want a drive connected at the same time you must obey the IEC protocol which is a pain under a multi tasking OS. With the joyports you just need to leave the keyboard and joystick alone during transfer.

[tlr]

Added the schematics and some info. No software published yet, working hard on it...
www.kahlin.net/daniel/dtv/cable.php

[David Murray]

I looked at your website. Very nice schematic. I wish mine could look so nice. Hey, I made a schematic on my website for my little project. I'm still thinking of trying to make it work on the joystick port. Can you look at my schematic so you know 100% what I'm trying to do and see what you think? Remember, this already works on the user-port.

galaxy22.dyndns.org/shuttlecraft/LED/index.html

And which port would I use? Since my program runs as an IRQ routine, I don't believe I'll have any trouble from the keyboard scanning routine. The main thing is I don't want any data outputting to my shift-register except for my own program.

[David Murray]

You know, never mind my previous post. I already tried it today and it doesn't work. I am able to send data out the port. But the keyboard routine seems to be sending garbage out BOTH ports 60 times a second. So it appears there is no way to use the joystick ports as output devices and use the keyboard at the same time.

[tlr]

adric22 said:

You know, never mind my previous post. I already tried it today and it doesn't work. I am able to send data out the port. But the keyboard routine seems to be sending garbage out BOTH ports 60 times a second. So it appears there is no way to use the joystick ports as output devices and use the keyboard at the same time.

I haven't peeked through the $ff9f keyscan routine in a while (18 years?), but I do believe it works the same way as my scanner i posted a while back. In that case it only sets one bit to zero at a time. You can utilize this by requiring atleast 2 pins going zero for your device to be activated. This will only be useful on Joystick Port 2.
Use one pin as active low select, and the use the other pins as normal. Some _combinations_ of keys may still affect the protocol, but it shouldn't be a real problem.

[David Murray]

Wow. that is a good idea. I'll have to check the chip data-sheet to see if that might be possible. If not I could always use an AND gate. Still, I'm not sure its worth the trouble. But is it as much trouble as building that darn power supply for the C64? Well, I'll have to think about it. Thanks for the idea.