Recent Posts

11

Games / Re: The Legend Of Zelda on Amstrad CPC+ [WIP]

« Last post by TotO on Yesterday at 17:51 »

it's the best choice because people love the game, the name and the brand.
They are also talking about it whereas there is almost nothing more than an intention
it's a marketing rule -> do not make new things, people are afraid of novelty

This game is not the prefered of peoples loving the name and the brand. Doing old things do not means doing the bad old things.

12

Technical Support / Re: New CPC 464 Owner, Tech Support Needed

« Last post by Fourdy on Yesterday at 17:26 »

UPDATE!


So, the 464 is in full working order thanks to Bryce, 6 of the 8 RAM chips were replaced and I believe a broken trace was repaired under a RAM IC also. I'm sure he'll be able to give some further detail as to what was done exactly.


I'd like to say thanks to Bryce for taking the time and effort to repair the board and send it back to the UK, top man!


Thanks all...

13

Games / Re: The Legend Of Zelda on Amstrad CPC+ [WIP]

« Last post by roudoudou on Yesterday at 17:10 »

The problem about the Legend of Zelda (NES) is the gameplay is too old and the difficulty form an other age.
Not sure that was the best choice for a CPC/PLUS port. At less, Link Awakening DX was prefered.

it's the best choice because people love the game, the name and the brand. They are also talking about it whereas there is almost nothing more than an intention
it's a marketing rule -> do not make new things, people are afraid of novelty

14

Games / Re: The Legend Of Zelda on Amstrad CPC+ [WIP]

« Last post by TotO on Yesterday at 16:49 »

The problem about the Legend of Zelda (NES) is the gameplay is too old and the difficulty form an other age.
Not sure that was the best choice for a CPC/PLUS port. At less, Link Awakening DX was prefered.

15

Programming / Re: CRTC detailed operation

« Last post by RichTW on Yesterday at 16:04 »

EDIT: just watched the best-rated BBC Micro productions on Pouet. Interesting ! I don't know how much you can compete against our Z80 3.3Mhz, maybe you are more limited with the slower 6502. I saw some FX exploiting line splitting (R9=0), which is what we also use to create most of the  best FXs on Amstrad (ZoomScroller and such may be doable on BBC machines too).

The main problem with the BBC, to be honest, is the horrible 1-bit RGB colour palette.  The CPU is pretty good as it's clocked at 2MHz (double the normal 6502 speed) and there's no contention with the video hardware, but you have to be inventive to work around the lurid colours!  The CRTC has the curious ability to be clocked at either 1MHz or 2MHz, so it can do character-by-character horizontal scrolling.  Bitshifters have been releasing some nice BBC demos recently, making use of all sorts of rupture techniques.  Games-wise, the jewel in the crown is probably Exile.

16

Programming / Re: CRTC detailed operation

« Last post by RichTW on Yesterday at 15:15 »

Merci beaucoup Longshot!

This is the first time I've seen the behaviour acknowledged, so it's nice to see that it's recognised elsewhere and not me misinterpreting the observations!

We know that there are two 'events' regarding the counters: one when the counter hits its corresponding register at N-1 (and the comparator goes high), and one when the counter gets reset on the following clock (where the comparator goes low again, generating a falling edge which clocks the next counter in the chain).

Simplistically, that would imply that setting Rn to Cn, no matter how late, would signal the comparator high, and the edge would fall on the next clock and trigger the next counter in the chain.

But, as you say, there seems to be something magic happening when C9=R9 which leads to some interesting effects.

This I never heard before:

For example, on a CRTC 0, if you modify R9 with the current value of C9, then C9 goes to 0, and C4 is incremented, even if C4 = R4

But it seems related to:

ignoring the updating of C4 when C9=R9 and R4 is modified with C4
In this situation, the R4 register update is ignored and C4 is incremented by 1. So it goes to 1.

The only difference each time is that, when it works correctly, the counters are equal to their respective registers at the start of the line.  It's as if there's some extra logic, which comes from the C0 reset signal, which is used to determine whether to start the 'end of screen / vertical adjust' logic.  The results of that determine whether C4 gets reset or not, so it's not such a straightforward check.  Do we know which value C4 has during the vertical adjust period?  Does it stay equal to R4, is it reset, or is it R4+1?

Here is a link that may interest you about other techniques that you may not have exploited yet on BBC
 https://open.amstrad.info/2019/08/20/archive-rupture-verticale-31-aout-1992/
 It's in French but I can translate it if it interests you.

Thanks!  I found a similar document on GitHub (also in French).  I can understand to a reasonable extent, but Google Translate helps immensely too!

17

Demos / Re: SID or something?

« Last post by BSC on Yesterday at 14:25 »

How much CPU time does the emulation take? And what do you mean by 6% of the AY capabilities?

The 6% thing was a pun relating to what Rhino wrote in the Batman Demo, where he stated something similar about CPC Demos

Anyway I think there's a lot of room for cool things to do with the PSG...

18

Demos / Re: SID or something?

« Last post by BSC on Yesterday at 14:23 »

Ok so it is like what I did for Imperial Mahjong I guess (which is, in all fairness, is inspired from what you did on your SID tracker!). Are the three channels on three different channels (that's what I do on IM), or do you mix them on one channel?

I knew that already ;-)

The three channels are mixed into one, otherwise the replay rate would be too low and the sound would be too harsh.
I am still experimenting with increasing the replay rate. Currently it is around 12 KHz.

19

General Discussion - Introductions / Re: Help! Losing the enthusiasm.

« Last post by BSC on Yesterday at 14:17 »

But that can't be it, because I'm pretty much alone with my Blu-Play interest too, and that doesn't change the interest. But maybe I'll lose interest for this platform again as soon as I've achieved my goals with it.   I suspect that'll be a while though.

No, you are not This Blu-Play thing sounds very interesting, I think I'll have a closer look in autumn (when I am naturally more inclined to spend my evenings at home).

20

General Discussion - Introductions / Re: Help! Losing the enthusiasm.

« Last post by BSC on Yesterday at 14:13 »

I actually have been thinking about a CPC music project lately - but a BASIC one. Mainly an idea for an effect that can only be done programmatically (which in my book means BASIC, because ASM/C is too tricky for me). But again, lack of time + knowing the amount of interest in the community won't be high = no go.

That sounds interesting - at least to me! And if it's interesting enough, I could even help with doing it in Z80.
So, if you don't mind, I would like to hear more about it.