Post by spiff on Jan 5, 2009 15:11:49 GMT -5
I have been digging out my work on a DTV-fixed Up'n Down, but I am facing some problems. As some of you may remember, I have previously (LONG time ago) mentioned this here, because I was having problems with the conversion. The game uses a TOD-timer, which is not available in the DTV. I attempted to fix this by using a raster interrupt. This mostly works, but because I just hooked into an existing raster interrupt, I don't get any timer updates when the player dies, at which point the raster interrupt is turned off. Also, hooking into the raster interrupt was not the easiest thing in the first place, because the game actually uses 4 raster interrupts.
These things can probably be solved. One way would be to use the regular timers, and upon reading calculate the value. Timer is only read when completing the level, so this should be doable, and would allow the timer to work without the interrupt. I would think this would be easier than fooling around with the raster interrupts, that get turned off from time to time.
Now, the second issue I'm facing is that it appears Up'n Down was made for NTSC. I have been looking at a lot of different versions, but all show the same results on PAL: Music runs too fast in the title screen (triggered twice per screen update), and the game runs slower on PAL than on NTSC. It looks like this is because all timing is done based on the interrupts, and I suspect fixing this is not easy. I played Up'n Down a lot on the C64, but not until I started working with the DTV-fix did I notice that on PAL, the fastest possible time to complete level 1 is 34 seconds, as opposed to 29 on NTSC. This also means you cannot get maximum bonus (need to complete in 30s or less).
Not being able to get maximum bonus (and the game running slowr than intended) is annoying me, but I'm wondering if fixing it is worth it? Also, some searching around on the 'Net shows that there is apparently a UK version. Question is if that has fixed the timing, or if that was just a "feature" when playing on a PAL system.
Any suggestions or help would be appreciated, as I'm about to give up converting one of my favorite games
These things can probably be solved. One way would be to use the regular timers, and upon reading calculate the value. Timer is only read when completing the level, so this should be doable, and would allow the timer to work without the interrupt. I would think this would be easier than fooling around with the raster interrupts, that get turned off from time to time.
Now, the second issue I'm facing is that it appears Up'n Down was made for NTSC. I have been looking at a lot of different versions, but all show the same results on PAL: Music runs too fast in the title screen (triggered twice per screen update), and the game runs slower on PAL than on NTSC. It looks like this is because all timing is done based on the interrupts, and I suspect fixing this is not easy. I played Up'n Down a lot on the C64, but not until I started working with the DTV-fix did I notice that on PAL, the fastest possible time to complete level 1 is 34 seconds, as opposed to 29 on NTSC. This also means you cannot get maximum bonus (need to complete in 30s or less).
Not being able to get maximum bonus (and the game running slowr than intended) is annoying me, but I'm wondering if fixing it is worth it? Also, some searching around on the 'Net shows that there is apparently a UK version. Question is if that has fixed the timing, or if that was just a "feature" when playing on a PAL system.
Any suggestions or help would be appreciated, as I'm about to give up converting one of my favorite games