Quote from: TotO on Today at 20:53As I know, the pull-up resistors are embedded into the AY-3-8910.Well, same is for 8912, but unfortunately it didn't work with my CPC464 (still needed external pull-ups) , so it's better have it that too as an option, don't you think?
Quote from: GUNHED on Yesterday at 21:23Wouldn't that also make the screen 1/4 height? Or am I missing something?Quote from: lmimmfn on 03:18, 11 August 22The regular character line height is 8 scan lines. So you need to transfer data for 8 scanlines every frame in case you want to scroll up or down.Quote from: GUNHED on 17:37, 10 August 22Excuse my ignorance but onQuote from: Axel on 14:28, 08 August 22What tricks could you try to enlarge the game window with the same or better framerate?- Use screen 64 byte in width (32 x 32 characters in MODE 1, but here MODE 0 would probably look more nice)
- Use CRTC characters only 4 scanlines high, or even better only 2 (instead of 8 like usually), this will make the scrolling more smooth, also gives extra time, because less V-RAM needs to be moved.
- instead of having sprites as data, use something like CoData (I use that for Filmemacher). Basically a program which draws the sprite or graphic element on screen. That's more quick compared to copy data.
- Use more RAM, this enables to unroll routines which contain loops. Also a speed up.
And finally: Do a complete rewrite instead of patching / enhancing / bettenering / etc. of an existing program. Alcon 2020 may serve as a well example for that ;-)
"Use CRTC characters only 4 scanlines high, or even better only 2 (instead of 8 like usually), this will make the scrolling more smooth, also gives extra time, because less V-RAM needs to be moved."
How does that make scrolling smooth? The CRTC has a fixed number of cycles to read the ram separately to the Z80, so how does reducing the character scanlines improve performance if its still a full screen(32x32)?
The CRTC is still working outside of the Z80 for screen refresh so I don't understand the comment.
In case you use only 2 scanlines, then you only need to transfer 1/4 of the data. In addition scrolling is more smooth and slower.
Quote from: ikonsgr on Today at 19:37so i'm thinking of creating an adapter to be able to plug the much cheaper ay-3 8910 (i find it on ebay for ~3euros...)Nice idea.
Since this chip is relatively easy to be damaged (because of the direct connection to the joy port), i think it might be a good idea, what do youthink?
Quote from: cngsoft on 23:33, 11 August 22Ideally, the package should include the sources and docs, nothing else; it would be the user's task to compile the binaries and to bring his own firmware files.And nobody will use it.
Quote from: Nich on 22:02, 11 August 22I've taken a photo of the screenshot from my own collection of AA magazines, and the player sprite does indeed appear blue instead of green.
Quote from: pelrun on 13:32, 11 August 22Turns out CGA has a 6845 CRTC, so there's quite a bit in common here with demos on the CPC. It's a type 2 though (edit: just noticed ralferoo mentioned this already...)Hadn't thought of that, but would make sense as it'd be a single bit at 15kHz.
I was hanging out with cTrix while he was composing the credits tune for this, it's a banger. Player is writing out a single sample per scanline, and the pc speaker hardware is only supposed to be a beeper!