PS/2 Mouse support on C64 and VIC20
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From: Jim Brain on 22 Nov 2009 15:38 David Murray wrote: Sorry to resurrect an older thread, but things take time to process. > Hmm.. Seems we have a concensus.. Everybody wants to plug it into > their existing joystick port. Okay, I understand the benefit of > this. But I should point out that the hardware to do this is much > more expensive. A good example is the device already being sold for > this purpose which costs around $40. My design would cost only $1.49 > for the cost of a Mini-DIN connector or could even be done for no cost > at all if the person wanted to solder the cables from the mouse > directly to the userport connector (I wouldn't recommend) but you get > the idea. As I see it, it will cost $3.00 or so for your design, assuming folks build it themselves. If a unit is sold pre-assembled, that would be around $7-$10. It's a very attractive price point. > Also I believe direct interaction with the PS/2 mouse would > give more reliable and accurate results. granted, I've never tried I am not sure about that. > this converter device, but I have tried my own design and the mouse > movements are just as natural as you would expect on a modern PC. And > it would leave the joystick ports free for other stuff. I think cost is the only true advantage. * PS/2 interface mouse movements are natural as well (not sure what you were implying with this statement) * PS/2 CLK signals come in at 80-100uS intervals. I assume your user port code hooks CLK to an IRQ and then reads all 11 bits of a PS/2 byte as a single loop. That's 1100uS where you can't service another IRQ. I don't know if there is a way to force the reading to occur when desired. PS/2 joystick port interfaces only require only CPU every 16000uS and requires only 3 PEEKs and the same amount of math as with user port solutions (assuming no mousewheel requirements. Mousewheel requirements require checking the joystick buttons every 45mS, but that's better than 80uS. * The joystick port is unavailable, but the user port is left free for interfacing. If you truly need a joystick and mouse on the VIC-20, there is a way to interface a second joystick to the VIC-20 via the user port that has been available for some time. * The user port is not very friendly to open-drain IO requirements of the PS/2 mouse. The VIA does not have software pullups, so pullup resistors are needed. > So.. My reasoning is that the direct connection of the PS/2 mouse is > the best way to go into the future. Although most VIC mouse apps would not require IRQs, those that do might have issues. It is true the normal 1351 does not appear to work on the VIC-20. But, there is no reason an aftermarket interface cannot be engineering to work. Such a device would be $4-$8 for the hobbyist, or $15.00 pre-assembled. Jim
From: David Murray on 22 Nov 2009 21:18 On Nov 22, 2:38 pm, Jim Brain <br...(a)jbrain.com> wrote: > David Murray wrote: > > Sorry to resurrect an older thread, but things take time to process. Well, based on the opinions I've seen here, I've decided not to bother with it anyway. I am not even 100% sure it would work, although I highly suspect it would since I got it working so nicely on the DTV. I think a few mods to run the mouse poll during the screen refresh to eliminate bad-lines would be the only needed change. My original line of thinking is that there aren't that many apps available that even have mouse support on the C64 and there are a total of zero apps that I use these days on the C64 which have mouse support, so I didn't know that backwards compatibility would be such an important issue for people. But I guess it is. The only app I ever used on the C64 or 128 that used a mouse was GEOS and I have no use for that these days.
From: Groepaz on 6 Dec 2009 15:49
David Murray wrote: > My original line of thinking is that there aren't that many apps > available that even have mouse support on the C64 and there are a > total of zero apps that I use these days on the C64 which have mouse > support, so I didn't know that backwards compatibility would be such > an important issue for people. But I guess it is. The only app I > ever used on the C64 or 128 that used a mouse was GEOS and I have no > use for that these days. backwards compatibility is THE issue for any kind of new hardware for the c64. as you say there are already only few apps that supports exisiting mouse solutions. and these apps are what whatever new mouse interface must work with, because noone will come around and patch existing software, or even write new one from scratch. -- http://www.hitmen-console.org http://magicdisk.untergrund.net http://www.pokefinder.org http://ftp.pokefinder.org Die [weiber] wollen entweder a) ficken oder b) sich dar�ber beschweren, dass m�nner nur ans ficken denken <Graham/Oxyron> |