EaglePlayer Amplifiers

Since EaglePlayer has been open source for 10 years now, has anyone looked at writing an AHI amplifier for it?

It was always my favourite player on my A4000, but has never worked on OS4 because of no AHI support.

Anyone have any info?

@Severin

It's 680x0 assembler.

can be downloaded from here:

http://bax.comlab.uni-rostock.de/~bj/ ... layer/index.html#download

it can possibly be developed using the VBCC assembler, if anyone is interested, in a retro coding experience.

@LiveForIt

Yeah I know the source is there. but it doesn't contain an AHI amplifier. As it comes with developer info for engines I was wondering if anyone atemputed one for it.

I kmow notheing about assembler, c or AHI so strictly and end user for this one.

@Severin

Well, I replayed to you but it was meant "@all".

You do not learn 680x0 in a sec or two, you need at least some basic understand of how microcomputer work.

Paula works in parallel with the CPU, give it an memory address and ask it to play from there. you do that by poking hw registers.

the same you can do with AHI, but you need to first open the AHI device, then you setup a AHI port and IORequest structure, you fill in with thing like Frequency and so on.

Then you set IORequest to address you like play, and use SendIO(), before you send a new SendIO(), you need to do a WaitIO(), or else thing crash badly I think.

Anyway all this has to be done in assembler

before exit, you need delete msgport, IORequest, and close the AHI device.

I was going to say that SendIO() is just a convenience function in amiga.lib which is equivalent to:

void SendIO(struct IORequest *ior) {
ior->io_Flags = 0;
BeginIO(ior);
}

While the latter part is true it turns out my memory was wrong and BeginIO() is the function that was in amiga.lib and SendIO() is the one that's been in exec from the start, which is a bit strange since SendIO() can't be used for "audio.device" because it clears the flags field.

When programming in assembler for 680x0 you would generally avoid amiga.lib functions as they use the C ABI which passes parameters on the stack.

hmmm... Why Assembler? I understand why it was used originaly, to get the required speed on 68020 but surely an 'Amplifier' is just a plugin and could be written with almost any language.

@Severin


EP_Catalog-Main.s

Show there might be possible to change timer from CIA to VBlank, I think this is done using register not high level API, so even if VBlank is used, the code is most likely no good.

EP_Main.s

Needs a rewrite, CIA timer used a lot.

EP_InternalPlayers.s

The CIAB timer is closed.

If you actually run the program and look at the menus timing can be set to CIA, VBlank and timer.device, so there shouldn't be a problem with timer.device.

@salass00

I'm not sure I understand, way do need to care about io flags? SendIO() is used AHI DEVICE implementation in mplayer. Should that be changed and how should it be changed?

UADE (Unix Amiga DeliTracker Emulator) despite having DeliTracker in its name uses mostly EaglePlayer replayers so in a sense EaglePlayer is already usable on AmigaOS 4.x through UADE.

@LiveForIt

Quote:

I just wrote a comment on something I've always found a bit odd, that is SendIO() being in ROM while BeginIO() is in amiga.lib when it would make so much more sense the other way around.

AFAIK audio.device is pretty unique in using io_Flags for anything other than IOF_QUICK. Certainly you don't have to worry about it with AHI.