Amstrad 464 Plus - Ticking like mad - C4CPC

[Neil79]

I've been testing out the C4CPC on the Amstrad 464 Plus and although it's easier to use with the GX4000 pad ( I prefer joystick ), I'm having an issue with some games. When I load up Auf Wiedersehen Monty I get a mad ticking/clacking sound, that gets ever worse if I move the joystick. This has also happened later on in APB, which didn't at first.


It's the same sound the Amstrad 464 Plus makes when it's first turned on. Any ideas?

[dragon]

I not have  the 464+ can be the tape rele?.

[Audronic]

@Neil79


Can you check your Power Supply ?


Ray

[Neil79]

@Neil79


Can you check your Power Supply ?


Ray

Hi Ray, it's this one


http://www.ebay.co.uk/itm/390531959470?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


Input 100-240V
50-60hz 0.5A


Output 5V : 2500mA

[dragon]

This has been treaty in the gx4000 thread time ago, I don't know if arnoldemu found the cause finally.

http://www.cpcwiki.eu/forum/games/converted-gx4000-cpr-the-topic/870/



But unfortunly. The emulators not support the sound of tape relay,and i don't have the 464 plus. So I can't do nothing with that  sorry.

[Neil79]

This has been treaty in the gx4000 thread time ago, I don't know if arnoldemu found the cause finally.

http://www.cpcwiki.eu/forum/games/converted-gx4000-cpr-the-topic/870/



But unfortunly. The emulators not support the sound of tape relay,and i don't have the 464 plus. So I can't do nothing with that  sorry.

Ah so it's the tape relay, at least it's that then


Thanks buddy!

[arnoldemu]

Ah so it's the tape relay, at least it's that then


Thanks buddy!

For 'Auf Weidersehen Monty' there is actually a bug. The keyboard scanning routine is at b5ed.

The instruction at b5fa forces PSG 'write register' operation AND motor on. (it should be OR &40 not OR &50)

joystick is at b5b9 and b5be sets motor. (should be LD BC,&F649 and not LD BC,&F659)

but the sound output routine at 9231 switches it off. (this is ok)

So it's bugged.

I don't know how frequent each is updated, but there is a chance that the relay has time to charge sometimes and at other times not, so it switches on/off.

On CPC, the write to PPI control sets port outputs to 0 and the time that the motor is on is much shorter. Unlikely it has enough time to switch.

Anything by Teque or Krisalis and some Grandslam titles I would expect the same to happen because they probably share code.

[dragon]

I have patchet it with arnoldemu tells, try if it work

[Neil79]

Nice one, I'll be trying it this week sometime


Thanks buddy

[Neil79]

You fixed it!! YAY!


Thanks, tested and working fine on my 464 plus

[arnoldemu]

You fixed it!! YAY!


Thanks, tested and working fine on my 464 plus

Let me know if there are others that do the same and I will find the bug.
Heroquest may be intentional (have to check again) but I doubt others are.

[Neil79]

Let me know if there are others that do the same and I will find the bug.
Heroquest may be intentional (have to check again) but I doubt others are.

APB does it on occasion, but it's not constant and not when you load it up




Ta

[arnoldemu]

I'm not sure. Is it in a later level?

The code for controlling the PSG using port f6 is not great - well it's not how I would do it.
Maybe this is the cause.

I'll work out a list of pokes for @dragon to try.

Best way is to write data, then 'write' then 'invalid'. But it does data, then 'invalid' then 'write'. Then does another write .... Sound possibly glitches because of it.

[Phantomz]

Does " Pac-Mania "still have the problem?

I know @chinnyhill10 had the problem with the first cpr I did, I tried a different version of the game, but unsure if the problem was still there as I haven't got a 464 plus to test it on.

[Neil79]

I'm not sure. Is it in a later level?

It did it a few times in the first tutorial right towards the finish line, then it stopped 

[dragon]

I'll work out a list of pokes for @dragon to try.

I think this game was Converted by phantomz.


In the other side i doubut heroquest  have problems in  the 464+  the 64k versión of gx4000 lost músic that is a interrupt in the second bank ram. Another theme is the 128k.

[arnoldemu]

Does " Pac-Mania "still have the problem?

I know @chinnyhill10 had the problem with the first cpr I did, I tried a different version of the game, but unsure if the problem was still there as I haven't got a 464 plus to test it on.

yes.

4137 should be ld bc,&f649 but it's ld bc,&f659
417c should be or &40 and not or &50

same programmers made this game and Auf Weidersehen Monty.

[arnoldemu]

apb:

1af is 3e 06. It seems to be scanning up, down, left, right, fire and maybe the last one was quit?
Last key seems to be disabled and set to ff,01.

It's enabling the motor. Set ff to 4f OR set 1af to 3e 05.

That should fix the clicking.

[Phantomz]

@arnoldemu Thanks for the info. 

I've just patched " APB " and " Pac-Mania ", unlike a lot of you guys on here I don't program, so hopefully I've done the fix ok on both games.

@Neil79 Can you test these versions please as I haven't got a 464 plus to test them on, thanks. 

[Neil79]

Nice one, I shall test later in the week as I put my back out today