View Full Version : running MP3 player on IBM5150a with inboard386

October 8th, 2017, 02:56 PM
the other day i did buy the soundtrack to the new blade runner movie. Normally i do only buy and play CD's and analog LP's.
But now i own a MP3 for the new movie. Must admit i am fan of the first blade runner - and looking forward to see the new movie in 2 weeks time.
I have had this IBM M-ACPA soundcard lying around for some time - and i did buy this card, to upgrade the old ibm-pc - it has a TMS340 cpu on the pcb.
(eventhough this card driver require 386 cpu and not only 8088 cpu)
I ones did try this card in the old PC, the sound quality is very high in my oppinion !

And today inspired by the soundtrack i did try the soundcard and it's MP3 capabilities.

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Setup: IBM 5150a with Inboard386/pc upgraded with Cyrix120GP (running 3*16Mhz = 48 Mhz). Future Domain 850 Scsi controller + disc.
VGA card , floppy card and the IBM M-ACPA soundcard.
Software: Windows 3.11 workgroup, winplay 3 v.2.3b5 - 16bit version. 5x86 Cache enabled !!


the winplay options were: Frequency "full" , stereo mode "Downmix", Resolution "8bit", CPUtype "80486 class".

First attempt, did not go well the soundtack MP3 did not start, and a message box apperaed:


...the only other MP3 i have lying around.(my own production - when my grandmother did write and publisize a book with old folktales and
i did help her by making a cd with mp3 containing the stories my grandmother did record dekades ago). These MP3 are of the 96kbps type.
And it worked ;)


cyrix cpu upgrade powering the inboard386

The conversion is done by the "powerfull" cpu and the card is just playing the waves. So the bottleneck is the motherboard with the 4.77Mhz bus.
So no soundtrack today, but MP3 on the old PC, only flaw , at sertain times "tick's" is heard. I suspect it is when software
application reades from disc , and the stream to the soundcard gets disturbed. I did alter the Frequency setting to "half" - witch not
sounded to nice, but the "ticks" dissapered! Perhaps, i can alter/remove this flaw by setting larger cache in the IBM driver. But i have
to remove driver and reinstall the driver to alter this setting (only seen the option to alter cache size at the point where i install
the driver).


October 8th, 2017, 03:07 PM
the IBM M-ACPA is capable of recording and playing compressed 16 bit(?) audio files to/from harddisc, with DOS application. Must admit i have not tried it yet :)

October 8th, 2017, 05:21 PM
Well, it's been proven that stuff like 386DX/40 + FPU can play low-bitrate MP3, and your Cyrix 5x86 is definitely faster.
Also, the 4.77MHz bus shouldn't be a real bottleneck here - CD-quality sound only needs 176 KB/s, well within the 8-bit ISA throughput, but I guess it would require some well-optimized software.

Anybody up to a challenge to play 44kHz/16-bit/stereo sound, from a disk file, on a stock 5150/5155/5160 ?
The only modifications allowed are:
* faster HDC+HDD, as the stock combo only achieves 85 KB/s
* an appropriate sound card, of course

I only have a Sound Blaster 2.0 in my XT clone - V20, 4.77MHz, CF card, and playing 44kHz/8-bit/mono WAV files works fine, using PLANY 1.5

October 15th, 2017, 09:18 AM
thank you for the point about the 176kb/s rate - well back to the topic MP3's.

The other day i did try, turn on power and directly play the 96Kbps playable MP3 fil. It worked and played the entire 15m58sec. without any "ticks". But try the not playable MP3, the system goes bad , and winplay would not afterwards play the "good" 96kbsp fil.
So perhaps my setup is sensitiv to errors, and do only function if no errors is encountered.

Today i switched the Cyrix586 with a TX486DLC and ITT4c87dlc-40 mounted in the sockets in the inboard386. Cache not enabled on the TX486.
But, it did not play smoothly. It took 1 hour 45 minut to play the 15 min58sec MP3! About 1 secund sound (okay quality) then silens
about 5 secunds...sound,silence,sound,silence so on..

Have to try out how high i can go in bitrate,with the cyrix586, and still get full quality audiowaves.

Question - what windows 3 application plays CD's from cdrom and uses soundcard for the digital to analog conversion ?
..the few i have looked at seems to be cdrom managers and letting the cdrom-drive convert the sound to analog waves :) ..


October 15th, 2017, 12:41 PM
Question - what windows 3 application plays CD's from cdrom and uses soundcard for the digital to analog conversion ?
..the few i have looked at seems to be cdrom managers and letting the cdrom-drive convert the sound to analog waves :) ..

I doubt that such a program exists.
But there's plenty of CD-audio grabbers for DOS, eg. CDDA2WAV and READCDA, and then you can play the WAV files under Windows.