Pat Brady

For distortion $Ax (square waves) this should work. For other distortions, it's more complicated, let me know if you need that. EDIT: this just blindly puts the closest value, without indicating which ones are useful. I'll add some formatting... EDIT: also the 15 kHz frequencies are all wrong... EDIT: I removed this file. Find updated version below.

The problem with overlaid 320A is that since transparency is based on pixel pairs, you end up with essentially the same restrictions as 320C, and with more cycles used for DMA. 320C is usually better. For 320C, set the colors something like this: P0C2 = white P1C2 = red P2C2 = blue (The order of those doesn't matter. What matters is that the colors you need are C2 of palettes that are either in P0-P3 or P4-P7.) The first 4 bits of each byte specify which pixels to color, i.e. which are not transparent or background. The next 2 bits specify the color for the first pixel pair and the last 2 bits specify the color for the 2nd pixel pair. So for example, if you want background-red-white-background, using the color definitions I listed above, set palette to 0 in the header and the graphics data byte will be 01100100 (look at it like this: 0110 01 00, which is off-on-on-off red white). Yes, it's confusing. Play with it a bit and you'll catch on. As PacManPlus mentioned, you may have to tweak your bitmap.

Sorry I missed the show. I fell asleep having stayed up late working on a different Atari project. Thank you for the kind comments.

Hmm, it doesn't sound quite right. I'll investigate tonight.

The music representations are very different but I can do the conversion (I would semi-automate it). But if you want to use Music Kit, that's certainly fine with me. I've tweaked Paul's player and attached the modified songplay.h along with my song.h. We may need to modify it further to allow multiple songs in one program. songplay.h song.h

Okay, I'll get started converting the title song first, then take a stab at the in-game music.

Here's an updated song that loops. 1942.bin

Might I offer an alternative TIA version of the title song? I did this with Paul Slocum's Music Kit but would be glad to convert it to whatever format you could use. ETA: I can also add another section to make it loop. 1942.bin

I love the look, distinctively 1942 and also distinctively 2600.

LMK if you'd like my assistance with that (for either or both chips).

Yes, "bounce back to the original location" is what I see. One possibility is: only charged attacks lunge forward and bounce back, uncharged attacks remain in place. Ideally there would be audible and visual feedback when charging is achieved. The existing pulsing is fine for the visual component, in other words don't start the visual pulsing until charged.

Nice game. Attractive, smooth, and responsive. Is there any significance to the enemy colors? My intuition is that enemy color should indicate something about enemy speed or behavior. In Legendary Spear I notice brown enemies tend to be fast but white and red ones seem indistinguishable. I also can't detect any benefit to charging the spear. Post #13 says the player should leap backwards, but I'm not seeing that.

What terrible news. My condolences to his family.

I just received my order. My wait was not quite 3 months. I knew up front it might take a while. Everything was in, uh, order. Thanks John!

It's on the list for my next AA Store order.

You can save 2 cycles per iteration by getting rid of the cpx if you change 208 to 209 then subtract one from each use of GridRow0 and GridRow11 (i.e. GridRow0-1,x). Make sure that GridRow0-1 and GridRow0+208 are on the same page (and same for GridRow11). I'm guessing you have defined your chars so that pods are between 18 and 28. If you can move them down to 0 to 10 then you can eliminate 2 cmp and 2 bcc per iteration.

Oh no. My condolences to his family.

From what I know of this game, I'm assuming the operations you need to do are: add a pod at a specific location, detect a pod at a specific location, promote or demote a pod at a specific location, advance the promotion timer for all pods. Of those operations, the last is the only one that can't be done efficiently from the charmap. Adding coordinates means that not only do (4,5) and (5,4) share an index, so do (6,3), (3,6), (7,2), etc. That seems like too much overlap. Also IMO you should only delete pods via gameplay. 418 locations can be mapped in 9 bits. So one possibility is: maintain your list of pods with each entry being 2 bytes. Another possibility: maintain a bitstream and peel off 9 bits at a time. I'm not sure about 7800basic, but in assembly you can use the C flag as a pseudo-9th bit for lookups. Yet another possibility: use 8-bit indexes, each referring to 1 or 2 different locations, then for each index in the list, check both corresponding locations for a pod. If you have spare RAM, you can avoid linear search through the list by maintaining a reverse map (i.e. map the coordinate to a list entry). If you use a true linked list, you need to track which addresses are available. If you use an array, you have to shift entries when you delete one. I'm not sure which is better. Array surely uses less RAM and is simpler to code, linked list probably has better worst-case cycle count. Hope this helps — it's entirely possible I misunderstood something fundamental.

Thank you for making it work on 48k machines. I will buy a copy for sure.

Mine arrived today! Very nice so far. Next time I need to remember to use a Genesis controller. I probably would not have ordered if @darryl1970 had not spoken up. I'm glad he did.

Oh, in that case, please add me to your lists for 2600, 7800, and Vectrex (and NES if you have any). Also might be interested in some CV stuff if that ship hasn't sailed. My wishlists are mostly carts that are not super-common but also not super-rare.

Okay, but if "probably feasible in the late 1980s" is the standard for authenticity, then cart RAM and some level of coprocessing are absolutely authentic.

I won't name names here because I don't want to pit any innocent programmers against David Crane, but I've seen some astonishing stuff in games that don't use extra RAM or a coprocessor. Though from what I've seen of Circus Convoy, I'd include the giraffe in that, so maybe I just have a lower bar for 2600 astonishment than you and MrTrust. Is a 128k ROM remotely authentic?

I have the binaries in this thread (post #83 and #87, August and September 2019) and also the ones in the zip file of your games. The zip file binaries are different and have April 2020 timestamps. What's the difference?

I believe R&V used a custom mapper in addition to its sound chip. I'm not sure what R&V has to do with Gauntlet anyway. Very different games with very different demands.