Has anyone ever thought of retro fitting an Amstrad with Hardware scrolling?

[Xifos]

Thanks.

I'm just doing tests here.
So there are too many c parts (using sdcc), and i am using the firmware.
I was just wondering how they did with mission genocide and warhawk ?
(it's perfectly done even at the top of the screen)

EDIT : argh, i had a look at my code, and i realize i was not putting the right values for r5 !
It was between 0 and 8, instead of 0 and 7 !
The result cannot be good !

[Xifos]

Here's another version.
This time the crtc values for r5 are good (you can see it at the sprite moving at the same rate of the scrolling)
I set the inks at black at the top, but it's not perfect.
For this kind of games, i guess i have to avoid sdcc and the firmware...

[sigh]

That is looking very nice indeed!
Are you planning to implement a slight left and right horizontal scroll?

[Xifos]

I know that some vertical shooters have a slight horizontal scroll.
But i don't know how i could do that in hardware...
I'm not even sure to be able to put others sprites and stay at 50 hz !

[Puresox]

That's looking great! Cheers for the taster.

[Puresox]

Just a question about the movement of the craft. I have noticed on a lot of vertical scrolling shooters on the Amstrad, that left and right movement seems spot on , but along the horizontal axis , the movement is laboured and not as quick. I know it may be partially optical illusion due to the scrolling giving false effect . Is this a limit or can it be altered?

[Axelay]

I was just wondering how they did with mission genocide and warhawk ?
(it's perfectly done even at the top of the screen)

If you look closely at the top of the screen in Mission Genocide, you can see the sprites emerging from the top of the screen extend above the top of the background by up to one character.  So that suggests there's a blank line written to the screen memory before it appears on screen, and the new background written line by line at the lowest point the top of the screen appears, giving the impression of a static screen top.  But nothing has been done to mask the sprites, perhaps because it isnt as noticable on a real monitor compared to in an emulator.

Are you planning to implement a slight left and right horizontal scroll?

Adding that to a vertical scroll on the CPC would negate the optimisation benefits to the sprite code of having a 64 byte wide screen.

[Xifos]

Just a question about the movement of the craft. I have noticed on a lot of vertical scrolling shooters on the Amstrad, that left and right movement seems spot on , but along the horizontal axis , the movement is laboured and not as quick. I know it may be partially optical illusion due to the scrolling giving false effect . Is this a limit or can it be altered?

I'm not sure, are you talking about the fact horizontal movement for the sprite is byte/byte instead of pixel/pixel ?

[sigh]

Adding that to a vertical scroll on the CPC would negate the optimisation benefits to the sprite code of having a 64 byte wide screen.

Okay.

I'm not sure, are you talking about the fact horizontal movement for the sprite is byte/byte instead of pixel/pixel ?

What'a happening is that up and down movement speed of the ship is different from the left and rigt movement speed. Could this be solved by having the ship move by 4 horizontal pixels?

I'm seriously looking forward to this game. I always wanted to see more smooth vertical scrolling shooters on the CPC.

[Gryzor]

Boy, and to think I found Lightforce to be smooth back then...


https://www.youtube.com/watch?v=NGzpEfp_6jo

[ralferoo]

And 1943:
[Amstrad Cpc] 1943 Longplay

[TFM]

That's software scrolling, not hardware.