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Newly made PCMCIA sound card

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Reply 40 of 46, by radiance32

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yyzkevin wrote on 2021-02-23, 21:39:

how is the sound when it plays through the computer speakers? I have brought the digital audio speaker pin out on my dev board to try it out but it is mono and i assume it sounds like crap more intended for modems? I had already been thinking about it for making fake modem sounds from my pcmcia esp8266 wifi model 🤣.

Midi (with that dream.fr chip and HardMPU Project) and OPL3 I am 100% confident I can do. For the other digital audio it is beyond me right now, but if I can move this forward a bit I know there are people here that can do this with their eyes closed just did not want to start it from the ground up. I have some IBM Mwave stuff I was interested to see what their "software/hardware" workaround is for lack of DMA in the early pcmcia versions.

The sound from the internal piezo speaker in the 200LX is horrible, and very quiet. (you literally have to put the 200lx on your ear like a mobile phone, when listening to digitized sound played through it)
If you want speakers, I think it's a much better idea to buy some modern micro speakers (like the ones they put in phones and tablets nowadays),
and put one or two (for stereo) in the LXsidecar housing. The 3d printed housing could contain some horizontal lines/holes on the front in front of the micro-speakers inside that allow the sound to come out,
and it would sound really good, like modern phone or tablet...
I would'nt bother with the internal piezo speaker of the 200lx,
also, I don't know if the PCMCIA interface in the 200lx has a connection to the internal piezo speaker,
and it would be a very dirty design if users will have to open up their 200lx'es and solder in some wires coming from the LXsidecar onto the piezo speaker inside the 200lx...

I think, if you want speakers, just buy a pair of those micro speakers that go into tablets and phones noawadays, and drive them with a tiny amplifier board in the LXsidecar,
you can get those tiny little amp boards very cheaply 😉

It's an interesting idea though 😀

EDIT: -> I think I could design the housing for the 200LX in such a way that it acts a little bit like a speaker box, and gives you a little bit more bass using the housing in the same way
as a speaker uses its housing to increase the bass response of the driver(s) in it. We could add a tiny port on the back so the speakers can push/pull sound through the housing, like many larger speakers have on the back (a port).

2nd EDIT -> Kevin -> Since we were talking about maybe putting in a headphone pre-amp, maybe we can find a small circuit board that has an amp for tablet/smartphone style speakers, an amplified headphone output, and a line out all at the same time... and have stereo speakers, a 3.5" headphone jack on the front and a 3.5" line out jack on the back of the LXsidecar...

3rd EDIT -> Kevin -> I've added an issue to explore this to our GitHub project, assigned to me... I'd like to look into this as it could solve a few of the ideas we already have and add a very useful feature: quality sound without headphones! 😀 )

Terrence

Reply 41 of 46, by digger

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yyzkevin wrote on 2021-02-23, 21:39:

I have some IBM Mwave stuff I was interested to see what their "software/hardware" workaround is for lack of DMA in the early pcmcia versions.

The following snippet from the VBE/AI 1.0 Specification (an attempt at a vendor-neutral abstracted sound driver API for MS-DOS in the '90s) might be of particular interest to you in this regard:

The basic interface is geared toward block oriented devices. This type of device may use a
DMA channel, or may have on-board FIFO memory for caching blocks of data. The
interface, for the most part, is the same for the application.

Non-DMA Block oriented devices can be supported as Block I/O devices that use timer
tick callbacks to keep data moving. The Disney Sound Source with a 16 byte FIFO, or
Media Vision AudioPort with a 1024 byte FIFO, are two examples.

(You can download this specification in PDF format through the VESA website, although you need to enter an email address before you are presented with the download site.)

So apparently a FIFO buffer in hardware, being fed by a software routine that hooks the timer interrupt so it gets called many times per second, is the best alternative way to implement a performant DAC if DMA is not available. This approach is also termed "pseudo DMA" elsewhere in that same document. Both the Disney Sound Source and the Media Vision AudioPort are parallel port devices, but there's no reason why such a mechanism couldn't also be implemented in a PCMCIA device. As for making it work with games, you could write a VBE/AI driver for it, and then use the already available DIGPAK or AIL2 wrapper drivers for VBE/AI to add support for it in quite a few games. For other games, a Sound Blaster emulator would have to be developed.

I've been working on a VBE/AI driver myself, and I'd be happy to share my knowledge with you if you're interested. 🙂

Reply 42 of 46, by yyzkevin

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lolo799 wrote on 2021-02-23, 22:37:
I can answer that one, it doesn't sound that bad really, it just depends on the laptop, "newer" ones use the same speakers for t […]
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I can answer that one, it doesn't sound that bad really, it just depends on the laptop, "newer" ones use the same speakers for the integrated audio card out and the basic system speaker sounds, so it's quite good on those.

On older models usually without integrated audio, the system speaker is just a piezo electric device which makes a somewhat distorted sound, it has its charm though!

I posted a sample here of me playing Doom using the Panasonic cf-vew211 opl3 based card:
Re: System Beeps - a PC Speaker music album

Interestingly enough the (also by Panasonic) fm radio pcmcia card can also output the audio signal through the system speaker, I tried on my 200lx and it was alright.

I assume it's mono, it's probably written in the pcmcia specs but I'm not going to look for the answer right now.

Great project you're doing yyzkevin, I'm eagerly curious to see how it goes.

Those sounded much better than I expected that is quite promising, I was specifically wondering about the HP200LX!

There are various pages of information about the speaker function of the spec, I have a few actual books helping me along as it is not that easy to find information online for this topic.

mpj4Qcxl.jpg

Reply 43 of 46, by yyzkevin

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radiance32 wrote on 2021-02-23, 22:38:
The sound from the internal piezo speaker in the 200LX is horrible, and very quiet. (you literally have to put the 200lx on your […]
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yyzkevin wrote on 2021-02-23, 21:39:

how is the sound when it plays through the computer speakers? I have brought the digital audio speaker pin out on my dev board to try it out but it is mono and i assume it sounds like crap more intended for modems? I had already been thinking about it for making fake modem sounds from my pcmcia esp8266 wifi model 🤣.

Midi (with that dream.fr chip and HardMPU Project) and OPL3 I am 100% confident I can do. For the other digital audio it is beyond me right now, but if I can move this forward a bit I know there are people here that can do this with their eyes closed just did not want to start it from the ground up. I have some IBM Mwave stuff I was interested to see what their "software/hardware" workaround is for lack of DMA in the early pcmcia versions.

The sound from the internal piezo speaker in the 200LX is horrible, and very quiet. (you literally have to put the 200lx on your ear like a mobile phone, when listening to digitized sound played through it)
If you want speakers, I think it's a much better idea to buy some modern micro speakers (like the ones they put in phones and tablets nowadays),
and put one or two (for stereo) in the LXsidecar housing. The 3d printed housing could contain some horizontal lines/holes on the front in front of the micro-speakers inside that allow the sound to come out,
and it would sound really good, like modern phone or tablet...
I would'nt bother with the internal piezo speaker of the 200lx,
also, I don't know if the PCMCIA interface in the 200lx has a connection to the internal piezo speaker,
and it would be a very dirty design if users will have to open up their 200lx'es and solder in some wires coming from the LXsidecar onto the piezo speaker inside the 200lx...

I think, if you want speakers, just buy a pair of those micro speakers that go into tablets and phones noawadays, and drive them with a tiny amplifier board in the LXsidecar,
you can get those tiny little amp boards very cheaply 😉

It's an interesting idea though 😀

EDIT: -> I think I could design the housing for the 200LX in such a way that it acts a little bit like a speaker box, and gives you a little bit more bass using the housing in the same way
as a speaker uses its housing to increase the bass response of the driver(s) in it. We could add a tiny port on the back so the speakers can push/pull sound through the housing, like many larger speakers have on the back (a port).

2nd EDIT -> Kevin -> Since we were talking about maybe putting in a headphone pre-amp, maybe we can find a small circuit board that has an amp for tablet/smartphone style speakers, an amplified headphone output, and a line out all at the same time... and have stereo speakers, a 3.5" headphone jack on the front and a 3.5" line out jack on the back of the LXsidecar...

3rd EDIT -> Kevin -> I've added an issue to explore this to our GitHub project, assigned to me... I'd like to look into this as it could solve a few of the ideas we already have and add a very useful feature: quality sound without headphones! 😀 )

Terrence

Yeah this is all good stuff for sure we are going to do it on our little LX sidecar. We can discuss the sidecar specifics in that github or in our palmtop thread, it is a bit different and will not be of interest to everyone here?. On that project we can go all crazy whatever we want because form factor is not an issue, on this "pcmcia card" has some other limiting factors so maybe it is not going to have headphone output for example, maybe we are going to go with feeding to the internal machine over speaker pin, or have lineout option fixed volume etc. Not sure yet.

Reply 44 of 46, by Gahhhrrrlic

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I suppose if the laptop is equipped with only a piezo then it would be kind of a waste for the sound card to work through that. However I have used many laptops with PCMCIA slots, which had nice multimedia speakers built in under the casing and like a previous poster mentioned, it sounds on par with today's tablets, etc. In fact 1 laptop I used (I forgot now which one), had a convoluted duct routed inside the case which exited at an oval shaped port, which was a mini sub-woofer. I mean we're talking a subwoofer with the volume of a laptop shell here so how good could it be but I thought that was the most awesome thing I'd ever seen in my life and no doubt it had better bass than any other integrated speakers... so yeah there's a spectrum for laptops, from cheap pc speaker to mono multimedia speaker to full stereo hi-fi + subwoofers 😁 There's absolutely nothing wrong with having a plug on the card to attach your own speakers. That's great if you can do it, but being able to route the signal through the computer's own speakers really grows on you when you want to use your laptop for what it was marketed for - portability. Playing Descent on a train with the computer in your lap and no paraphernalia to worry about really is a pleasure once you've tried it.

https://hubpages.com/technology/How-to-Maximi … -Retro-Computer

Reply 45 of 46, by yyzkevin

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Kind of reminds me I think of maybe Compaq Presario laptops of the early 2000's that had some kind of ported woofer setup if I recall.

I think we will make the card output to the internal speaker when no external headphones or speaker is attached.

Gahhhrrrlic wrote on 2021-02-24, 07:20:

I suppose if the laptop is equipped with only a piezo then it would be kind of a waste for the sound card to work through that. However I have used many laptops with PCMCIA slots, which had nice multimedia speakers built in under the casing and like a previous poster mentioned, it sounds on par with today's tablets, etc. In fact 1 laptop I used (I forgot now which one), had a convoluted duct routed inside the case which exited at an oval shaped port, which was a mini sub-woofer. I mean we're talking a subwoofer with the volume of a laptop shell here so how good could it be but I thought that was the most awesome thing I'd ever seen in my life and no doubt it had better bass than any other integrated speakers... so yeah there's a spectrum for laptops, from cheap pc speaker to mono multimedia speaker to full stereo hi-fi + subwoofers 😁 There's absolutely nothing wrong with having a plug on the card to attach your own speakers. That's great if you can do it, but being able to route the signal through the computer's own speakers really grows on you when you want to use your laptop for what it was marketed for - portability. Playing Descent on a train with the computer in your lap and no paraphernalia to worry about really is a pleasure once you've tried it.

Reply 46 of 46, by radiance32

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yyzkevin wrote on Today, 01:27:

Kind of reminds me I think of maybe Compaq Presario laptops of the early 2000's that had some kind of ported woofer setup if I recall.

I think we will make the card output to the internal speaker when no external headphones or speaker is attached.

Gahhhrrrlic wrote on 2021-02-24, 07:20:

I suppose if the laptop is equipped with only a piezo then it would be kind of a waste for the sound card to work through that. However I have used many laptops with PCMCIA slots, which had nice multimedia speakers built in under the casing and like a previous poster mentioned, it sounds on par with today's tablets, etc. In fact 1 laptop I used (I forgot now which one), had a convoluted duct routed inside the case which exited at an oval shaped port, which was a mini sub-woofer. I mean we're talking a subwoofer with the volume of a laptop shell here so how good could it be but I thought that was the most awesome thing I'd ever seen in my life and no doubt it had better bass than any other integrated speakers... so yeah there's a spectrum for laptops, from cheap pc speaker to mono multimedia speaker to full stereo hi-fi + subwoofers 😁 There's absolutely nothing wrong with having a plug on the card to attach your own speakers. That's great if you can do it, but being able to route the signal through the computer's own speakers really grows on you when you want to use your laptop for what it was marketed for - portability. Playing Descent on a train with the computer in your lap and no paraphernalia to worry about really is a pleasure once you've tried it.

Yeah, i agree 😀 If there is a 3.5" jack inserted into the headphone jack, use that, if not, send audio into the 1 watt amp IC and to the 1 watt micro-speaker 😀

Terrence