Space Invaders / Connect-4

[Lechuck]

As for the sounds effects, the explosions sounds are great now. I couldn't tell much difference to the invaders marching sound though. I took the liberty of using the tool I posted earlier to mock up how I think the notes should sound to closer match the arcade (attached) if you wanted to add the four note pattern.

Anyway, thanks once again!

I have just uploaded a new version with the four notes pattern you provided. Please, let me know what you think (I can still 'play' with sound duration...)

Cheers

[beamrider]

Thanks LeChuck

I have just played it and it's a big improvement. Makes the alien advance more menacing. It's funny how these small details make huge differences.

I rest my case now, well done.

It seems arcade perfect to me.

[Lechuck]

Thanks LeChuck

I have just played it and it's a big improvement. Makes the alien advance more menacing. It's funny how these small details make huge differences.

I rest my case now, well done.

It seems arcade perfect to me.

Great to know! Thanks for letting me know.

Cheers

[beamrider]

I had a good session playing this on real hardware this afternoon and it looks really great on the CRT.

Have to report a couple of bugs though:

(1) When using the keyboard it seems you are unable to move and fire at the same time.
(2) occasionally I hit the UFO, but my shot didn't reach/kill it.

Regarding (1) - I think you will need to scan the keyboard matrix directly to detect the fire key being pressed or not. It's not something I've done before but I suspect someone on here can provide more guidance how to achieve this or perhaps point you to some code.

[Lechuck]

Hi beamrider,

Thanks for the feedback.

(1) When using the keyboard it seems you are unable to move and fire at the same time.
Regarding (1) - I think you will need to scan the keyboard matrix directly to detect the fire key being pressed or not. It's not something I've done before but I suspect someone on here can provide more guidance how to achieve this or perhaps point you to some code.

Yes, I also noticed that. I’m reading the key pressed from mem address 197 and, so, I can only detect one key. I remember having seen a post about detecting multiple keys by reading the address with the row/column being scanned so, yes, I should be able to implement it. Something to include in the next version.

(2) occasionally I hit the UFO, but my shot didn't reach/kill it.

When I changed the movement of the mother ship from char to bit level I also had to include something specific to detect the colission so it is very likely I made a mistake. Will review that part to see if I can find the bug

Cheers

[Lechuck]

(1) When using the keyboard it seems you are unable to move and fire at the same time.
(2) occasionally I hit the UFO, but my shot didn't reach/kill it.

Regarding (1) - I think you will need to scan the keyboard matrix directly to detect the fire key being pressed or not. It's not something I've done before but I suspect someone on here can provide more guidance how to achieve this or perhaps point you to some code.

Should be fixed now. Just uploaded a new version. I have included the multiple keys detection to allow moving and firing at the same time also with the keyboard and have changed the way collision with the mother ship is checked (I was doing something very odd for that, I'm surprised it was working at all... )

Cheers

[beamrider]

Thanks for the quick turn-around.

Had a quick try and both those issues seem to be fixed now, and it plays great

Will have an extended session at the weekend again on real hardware.

[nbla000]

I have just uploaded a new version with the four notes pattern you provided. Please, let me know what you think (I can still 'play' with sound duration...)

WOW!!! I have been away for a while and in the meantime I have lost this pearl !

I think that now is perfect, is the best Space invaders conversion for home coumputers in my opinion, very good job!

[Lechuck]

WOW!!! I have been away for a while and in the meantime I have lost this pearl !

I think that now is perfect, is the best Space invaders conversion for home coumputers in my opinion, very good job!

Thanks a lot! I’m very glad you liked it

Cheers

[Lechuck]

Hi,

I've just uploaded a new version with minor changes:

- I have slightly modified speed of shooting (I think that now, game pacing is closer to the original)
- I have modified the way sounds are played. Previous version was using an IRQ interrupt to play the Alien's movement sound, but rest of sounds were being played from the 'main' loop (some sound effects were 'too fast' to be reproduced in a 60 times/second basis). As a result, as game was progressing (making it faster), some of the effects could sound diferently (this was specially noticeable in the sound effect for Aliens destroyed). In this new version, I'm using a VIA timer and a NMI interrupt to reproduce the sounds.
- I have fixed a couple of minor bugs (one affected the way buildings were destroyed when Aliens were in the lower part of the screen; the other provoked that, sometimes, a building char, was completly deleted instead of 'gradually' destroyed)


Cheers

[highinfidelity]

Wow, further new improvements!

I have to apologise for not having tried the improved versions yet, but unfortunately I am still having problems of dizziness/vertigo and I'm trying to avoid fast moving and flashing things, videogames included, whenever I can.

Still I can't wait to try it out, and judging by other people's comments I'm sure you did a terrific job.

[highinfidelity]

I am finally having occasional moments of relief, and yesterday I felt that I could perhaps enjoy half an hour of videogaming without having to "pay the fee" as aftermath.

I immensely enjoyed the last improved version of your Space invaders port! The intro screen is absolutely perfect now and adds greatly to the overall "classy" feeling that this port delivers. The mother ship sequence is now perfect and very enjoyable - I indeed get tempted to pursue it very frequently and miss a ship nearly every time just as in the original arcade!

I have the feeling (but again: might be just a feeling) that there is a bit too much of lag in the shoot-hit-explode-shoot sequence. Undoubtably it is correct that also in the original arcade game firing is inhibited until the explosion sound and graph are both over, but I have the feeling that the next shot is released a liiiiiittle sooner. But again, it may be just bad recall.

A detail that I think can be easily improved is score memory: when the game is over but the player didn't beat the previous best score, the score of the last game session is immediately reset to zero as the intro screen is engaged. I think it could be easily programmed to be kept in memory, so that it is being kept displayed during the intro screen, side by side with the best score, and then reset only when a new game begins.

[Lechuck]

I immensely enjoyed the last improved version of your Space invaders port! The intro screen is absolutely perfect now and adds greatly to the overall "classy" feeling that this port delivers. The mother ship sequence is now perfect and very enjoyable - I indeed get tempted to pursue it very frequently and miss a ship nearly every time just as in the original arcade!

Great to know. Thanks for the feedback!

I have the feeling (but again: might be just a feeling) that there is a bit too much of lag in the shoot-hit-explode-shoot sequence. Undoubtably it is correct that also in the original arcade game firing is inhibited until the explosion sound and graph are both over, but I have the feeling that the next shot is released a liiiiiittle sooner. But again, it may be just bad recall.

Dificult to say, when comes to timing...
Explosion is kept in the screen for 1/3 second (as it is, I think, in original Arcade). After that, next time we press the fire button, a new shot will be created (there shouldn't be any lag between the moment the explosion is removed and a new shot is(can be) created).

A detail that I think can be easily improved is score memory: when the game is over but the player didn't beat the previous best score, the score of the last game session is immediately reset to zero as the intro screen is engaged. I think it could be easily programmed to be kept in memory, so that it is being kept displayed during the intro screen, side by side with the best score, and then reset only when a new game begins.

Good point. Yes, that is right, in the original, score from last game is kept until a new game is started. Will include that next time I upload a new version.

Cheers

[Lechuck]

A detail that I think can be easily improved is score memory: when the game is over but the player didn't beat the previous best score, the score of the last game session is immediately reset to zero as the intro screen is engaged. I think it could be easily programmed to be kept in memory, so that it is being kept displayed during the intro screen, side by side with the best score, and then reset only when a new game begins.

Good point. Yes, that is right, in the original, score from last game is kept until a new game is started. Will include that next time I upload a new version.

Cheers

Sorry, I had forgotten this...

Just uploaded a new version (same link as before). Now, player's score is set to 0, only when a new game starts.

Cheers

[highinfidelity]

Good job, thank you very much!