Sohl

The pandemic... I was sort of imagining what would be going on inside my body and everyone else's in early 2000. I thought it would be empowering or at least psychologically comforting to be able to "fight" a virus in a more direct way via gameplay. So I wanted to have some fighting game elements, not just a shooter. I didn't get a direct fight against the viral RNA strands implemented like I first considered (that part ended up more-or-less "shooter" style) but I got a "bounce" effect for Energy molecules into the mitochondria and, closer to my earlier thought, the idea of "thumping" the cell membrane to shake loose spike protein that can be used to generate more antibodies. I added some resource management ideas with powerup effects to make the game play a little more strategic, but very loosely based on health/metabolism dynamics. But the main dynamic is use antibodies to neutralize each virus then gobble it up with macrophage, and to slow down the growth of new viruses as you rebuild more antibodies. By the way, I tinkered a LOT to make the virus graphics look good on the 2600. I use some different methods depending on what part of the different screens the virus appears in. The screen cap you have there is formed by a player sprite for the red spikes over a playfield square (one bit), so you don't see what would be bottom row of the whitish virus body as you can when they are free-floating. But in that part of the screen, the virus is supposed to be implanted in the membrane, so I can sort of justfy why you might not see part of it. Right?

Thanks @magnusfalkirk. Glad you and @Living Room Arcade found it and/or found it interesting! I've been a little scarce lately, so I didn't even realize you've been referring to my game Immunity.

That's an awesome video @BitJag! I'm really happy how your work on the box and manual turned out. You took my rough vision and made it better and more complete with your tremendous talent and skills. I'm honored to have you as my artist and manual designer! I'm going to forward this video to friends and family!

Thanks for grabbing a copy of my game Immunity! I hope you like it and the packaging and manual I put together with @BitJag and @Albert.

Very cool game... I love the play mechanics demo'ed on the ZPH show. I also wondered about the Driving controller, but you have ruled it out I saw earlier in the thread.

I love this poster, @RevEng!

I would love to have XPx to directly set the X positions, even if we need to use the direct LFSR values to do so. The other things you list for TIA would be nice too. For the 6507, a "load accumulator with one of two options, based on a condition flag" instruction would be great. I think there is an undocumented one that sort of works, but maybe has some other side-effect or limitation.

Cool look so far! The ball is only available once per scanline, and is the same color as the playfield foreground (COLUPF), but can be a few different widths. Ball width of one or two color clocks (= 1 or 2 sprite pixels) can help smooth out playfield "pixels", which are 4 color clocks wide each. Missiles do allow repeats like the player graphic sprites, but are the same color as the corresponding player sprite (COLUP0 or COLUP1), so can be tricky to use in some cases. A lot of game ports made back in the 2600 heyday took a lot of liberties with look and layout (arguably too much liberty, in the cases of Donkey Kong and Pac Man), but I would encourage you to simplify the look a bit more to more naturally fit the rendering capability of the 2600. CDFJ+ can help make more complex graphics possible by streaming data from an ARM processor in the cart to the same memory location visible to the 2600's CPU so you don't need as much code on the 2600 to jump around and manage pointers and offset indices, etc. But if the 2600 is producing the picture, it needs to be done through the TIA's graphics objects and color registers.

If the color change needs to happen cleanly at only one or a few locations, why can't you waste a few cycles with NOPs or 4cycle writes, etc. so that the real STA that you want to do hits when you want? Am I missing something special about your situation? Nevermind, I think you are talking about the 3 color clocks per CPU cycle.

That's awesome, but I didn't catch your notice in time, and was kind of busy on Tuesday. Thanks for playing during your show. One hint for higher score is to hold the fire button longer, especially when the beam speeds up. At the faster sweep speeds, this allows you to sort of scoop the objects along rather than bump them. Early though, quick taps of fire can sometimes allow you to double-bump the objects in one beam pass. Also, press & hold fire earlier to make smaller pushes when you have objects close to the incinerator. There's a couple of fixes and other improvements I know I want to make: 1) It's too easy to start a new game immediately after loosing... I need to have the game ignore the fire button during the "loose" music motif and perhaps a bit longer to ensure you see your final score. 2) I want to make the Advanced difficulty switch setting start the same with speed level 2 (currently both A and B start the beam at speed level 1). That would allow better players skip the slowest phase. The speed is how many pixel positions or scanlines the beam advances each video frame (currently it is 1, 2, 3... no matter the difficulty, and then 4 is possible if difficulty is set to A). 3) Make the current moving objects just a little faster. 4) Add additional object types with unique ways of moving 5) Slow the title music, maybe add a second voice accompaniment I haven't decided if I want to grow the feature set with things like: 1) Game version where you set the beam sweep direction each time. 2) Two-player version(s)

I agree it's possible. I did a lot of asymmetric playfield in my game Immunity for score and status bars. I recommend pre-computing as much of the math as possible and put it in tables for relatively simple look-up operations rather than number crunching on the CPU.

Some notes on the typical behavior of space-varmits™ * Creepers: Move slowly outward from the incinerator. Sliders: Move in a straight horizontal or vertical path, usually whichever would be longest path to the edgewhen the varmit begins motion. Zipsters: Chooses a random direction, slightly biased away from incinerator, but they are know to frequently zip right into it! Zagsters: Generally alternate between a horizontal and vertical path away from incinerator. Pushing any of these varmits to a new location will trigger them to re-establish their path. * (not actually trade-marked... yet, at least!)

Sweep Shot Welcome Space Station 48-307 Custodial Cadet! Your first job is to operate the station debris incinerator, which is enhanced with a laser-guided ion-beam sweeping device to push unwanted objects, including some nasty space-varmits, into the incineration zone. The ion-beam is easy to operate, but tricky to master! The laser guide line will continuously sweep across the station sector in a repeating pattern. You inject an ionic pushing wave when you press your control button. The guide beam will glow orange as it energizes… but press too long and it looses effect. After you release the button, the beam will require a fraction of a second to recover before it can be utilized again. Note that you push the objects stronger if the beam activates on or very close to an object, and pushes more weakly if activated before reaching the object. Timing is critical! Station “dust bunnies” will not move on their own, but the space-varmits will! Nudge them quickly into the incinerator in the center of your sector or they can escape. You will hear a warning tone if the object is close to the sector edge. If four objects escape, your shift will be terminated early and you will be sent to kitchen patrol… or worse! Your performance will be monitored, and you will receive more performance points if you incinerate the unwanted objects with fewer ion blasts. The more quickly-moving objects can earn higher amounts of performance points. If you clear all of the objects in one sector, you will advance to another sector, but the ion-beam sweeping rate will increase each time up to the max speed seen in the third and later sectors. Many custodial cadets find that the higher sweeping speed becomes easier to use than the slowest speed once the timing is familiar. Objects and space--varmits: DustBuns: Creepers: Sliders: Zipsters: Zagsters: A good, clean incineration: We’re counting on you to maintain a clean station. Now get to it! [2600 control notes: Reset Switch will restart the title screen; press Fire on the title screen or a game-over screen to begin play; pressing Fire on the game over screen (which looks white with black score digits) for a longer period will restart the title screen again; only the Left Joystick fire button is used to play; The Left Difficulty Switch allows the beam sweeping speed to reach a level of 4 (beginner is limited to 3); Right Difficulty switch disables ongoing beam rumble sound in the the A position; there are no game variants.] sweepshot - 2022Dec31.bin

Coming later today (Dec. 31st)! Just needs a bit more cleanup and tuning... Will post my best version around 3:00 PM EDT.

Here is a new playable demo. It has the new features described in my recent posts minus two that I'm holding for potential commercial release: 1) Resting (skip ahead) 2) Two of the six tissue types I increased some of the movement rates to make it a bit more challenging. The beginner difficulty level is perhaps still a bit easy, but the advanced difficulty is quite hard to beat in my opinion. I don't know of any major issues with this, but if you notice a bug or weird issue, let me know! Also if you have feedback on the gameplay challenge level, etc. that would be great to hear. Happy Holidays! imm _demo_2022dec23.bin