Sheddy

Great news about the new version. Thanks, this is just such a fantastic utility . (It's sadly addictive leaving your PC churning away all day and looking forward to coming back home to see how close it's managed to get...) In keeping with the Amiga theme. One of the original iconic "Wow" pictures showing off the Amiga Only 76 Million, laoo palette, s=5000 sheddy-dpaintkingtut.xex And something else. I was hopeful that no dither would be necessary for this one due to the layout, and I'm not too disappointed 168 Million, laoo palette again, s=5000 sheddy-mariodance.xex

sheddy_spaceharrier.xex 236 million evaluations (euclid) pretty streaky in places but robot gun much better than other attempts

Told you my PC was slow. 236 million evaluations (euclid) pretty streaky in places but robot gun much better than other attempts sheddy_spaceharrier.xex

Please work from the original source - the arcade version! This is an abbreviated animation that does have the waving. I've been playing with Rastaconverter too, but my PC is slow and no good results yet (so maybe the original isn't a good source after all)

How do things fare with DLIs going on? - The incredibly frustrating NMI hardware bug ( http://www.atariage....interrupt%20nmi) meant I decided to use combined channels for precise IRQ timing to try avoid the darn NMIs 99.99% of the time in the end. If the RLE can be combined more efficiently with 16-bit timer as well... Edit: I've assumed your using 64Hz mode though. If all sound was done in 15.??Hz mode that wouldn't be a problem...?

Ah, that'll teach me to skim. That must be a neat trick being able to reduce the interrupts that much without too much overhead - Will be checking it out in more detail later. Thanks An explanation of PWM? It works like this: When a frequency is too high to pass through a circuit (such as a low-pass filter), what you get is the average level instead of the rapid changes in level. Of course, unless your filter is perfect, you'll get some of the original frequency, but it collapses to the average level as the filter improves or the frequency goes up. So, this means we can make a DAC using just a square wave and a filter. If the square wave oscillates between 0V and 5V with a 50/50 duty cycle, we get 2.5V out of the filter/averager. If we change to a 25% low/75% high square, we'll get 3.75V out. And if we flip that wave (75% low/25% high), we'll get 1.25V out. So, it's the width of your pulse that determines voltage, and you can make various analog levels using a single digital output. Thanks for the explanation Bryan Kinda good to know I was only partially confused (although, as they say, "a little knowledge is a dangerous thing" )

Wow! This is giving amazing results. Excellent stuff Andy. Still not really understanding PWM though. Hard to believe so few IRQs are needed. Anyone want to have a go at explaining in fairly simple terms? (looked at Wikipedia a while back and thought. Er, what?!) Not looked at the code either yet. Please correct as necessary! There is a very high frequency tone played, that is too high to hear. At very specific points in time the tone is stopped for a very short time, reducing the average volume for that part of the waveform? Ear only hears average volume. So, if the frequency is so high, how can you make sure what the exact volume at any point in the wave is if you only have control at wavelength resolution? is it enough just to be on or off? Thanks!

Very slick work, Jason. Great use of colour. I too would love to see power-ups and more bullet hell going on, but I'm guessing there is still more to come

yep check out the downloads section of my site

It depends on each object's size and how complex the masking required for compiled sprites, so it varies a lot. There's a spreadsheet in the source code download "tools" folder with code size and CPU cycles for every object's pre-scaled and pre-shifted frames. EG: biggest frame size of "bush" takes 1449 bytes for 3640 cycles. Smallest frame is 33 bytes for 72 cycles. All 22 frames for fairly smooth movement take 7700 bytes. ...but biggest frame of "tree" takes 3186 bytes for 8070 cycles. Smallest frame is 79 bytes for 175 cycles. All frames are 17682 bytes! Using x register to hold repeat masks, biggest "tree" could be 3137 bytes for 8106 cycles. Not usually many repeat masks for small frames though Using a 4 colour screen instead of pseudo 16 colour screen would nearly halve those figures (and less screen memory needed too of course) and less need for ultimate speed Using "quite fast" sprite routines like demo version would give a lot more space for objects. On average, about 20 objects fitted into extra 64K of the 130XE. They were less complex than the ones above and only 4 colours each though. Can't remember exactly now, but nearly twice as many cycles were needed sometimes for similar object than the compiled sprite method.

Er, Space Harrier with a limited amount of enemy types in between loading? You'll have to be more specific with the question

Me too. That grid is spot on, as is the left/right "scroll" of it and stuff on the ground - same as arcade (atari one is just simple 3d parallax as I couldn't figure out what algorithm/transforms are going on in the original) This is my favourite version though, when anyone asks why I didn't use GTIA modes http://www.youtube.com/watch?v=cs-4Zu0DN2g&feature=related

It's a shame they're only using the 2002 demo version which is much more primitive than the finished game

Just to clarify, yes it is for the writeable carts which you can do (for free) yourself. Some people are just offering them pre-done for convenience.

Yep, the 128k thing you have will be the rough stage 1 demo, which doesn't have stereo. The finished atarimax cart only game does though.

Game itself is free - no need to ask me

Very nice - something not too simple, yet not too vastly overambitious for A8 either. ExedExes had crossed my mind more than a few times as an interesting project

I like to define it as "anything which fundamentally alters the character of the machine". Hence I have no problem with banked carts and RAM carts, internal RAM expansions, IDE interfaces, etc, etc. Faster processors, higher resolution graphics and / or greater bit depth, blitters, co-processors, etc, are on the other side of the line. They delegate work away from the CPU and Antic and imbue the machine with capabilities which simply may not have been achievable "back in the day", while hard disks, banked carts and RAM upgrades were relatively common in the machine's heyday. That seems reasonable to me too. Of course, if one machine is using a RAM expansion and the other is not, then it is not a totally fair comparison either, but much fairer than one off-loading processing to extra hardware.

Probably NTSC would be better (and easier to reencode for YouTube). For the original demo pictures for Technicolor Dream, have a look on Fandal's site here: Technicolor Dream I find it slightly disturbing how many of those pictures I remember from the review in Page 6 magazine etc. - obviously made an impression on me at the time! Cheers, Simon If you're going to vid Gem Drop, I suggest using Altirra ... you can select Frame Blending which will eliminate the flicker. If not, NTSC is better because the refresh rate will be faster, makes the colors blend better with less flicker. As a request (I know I wrote it) but maybe you could do up a few levels from my old Sky Scraper turbobasic game ... it's on this forum somewhere. 2nd Altirra as the easiest way. YouTube won't allow any 50 or 60 Hz upload, they'll get converted (very badly) to 25 Hz. If not using Altirra, you need to apply some blending processing beforehand, in something like Virtualdub.

Worked for me (well, until the money was all gone!)

Great attention to detail.

You're welcome Sorry it was such a pain, but it's useful information for future!

Strange. Have you tried downloading it again in case it's somehow corrupted? Working OK on my carts. Maybe the older flash utility I created it with can't recognize the new batch of "bank zero" cartridges. Here is the programming image made with the latest maxflash cartridge studio (Tools/Convert BIN to ATR programming image) sharrier (maxflash image).atr

To be fair, it's not all that easy to find the manual now