PDA

View Full Version : DIY audio card for IBM PS/1 2011



nestor
July 27th, 2011, 04:24 AM
I built this prototype card with a YMF262 and its YAC512 DAC (it is 100% AdLib compatible):

http://img827.imageshack.us/img827/8039/20110711163856491.jpg


And here is a video (720p):


http://www.youtube.com/watch?v=V9CZQzpzYA0

I hope you like it.

Great Hierophant
July 27th, 2011, 06:11 PM
Is it located at the Adlib I/O ports of 388/389?

Chuck(G)
July 27th, 2011, 06:25 PM
Nice work! It's good to see someone creating their own peripheral boards. :thumbsup:

nestor
July 27th, 2011, 11:16 PM
Is it located at the Adlib I/O ports of 388/389?

That is the only way to achieve AdLib compatibility ;)


Nice work! It's good to see someone creating their own peripheral boards. :thumbsup:

This was a dream 20 years ago when I was a kid, in that time it was impossible to put a soundcard in a PS/1...

angel_grig
July 28th, 2011, 08:10 AM
Wow!Excellent work!Can you tell us more info?It it ISA compatible?(I see no ISA connector)

Maverick1978
July 28th, 2011, 08:39 AM
Nice work! Would love to see this documented into a wiki of some sort, with detailed schematics and pictures, especially since this seems to be adapted to use a proprietary connector found in the PS/1 (which I've sadly never gotten to crack open and experience)

nestor
July 28th, 2011, 11:34 AM
Wow!Excellent work!Can you tell us more info?It it ISA compatible?(I see no ISA connector)
Yes, it is ISA compatible but the IBM PS/1 models 2011 and some 2121 don't have ISA connectors. Instead there is a 34 pin header to attach a very rare PS/1 Audio Card, so I used it.


Nice work! Would love to see this documented into a wiki of some sort, with detailed schematics and pictures, especially since this seems to be adapted to use a proprietary connector found in the PS/1 (which I've sadly never gotten to crack open and experience)

The schematic is based on the one from the OPL2/OPM Sound Card project from this forums, but using a OPL3 and a YAC512. The hardest part was to discover by trial and error the approximate pinout of the proprietary connector :evil:

pearce_jj
July 28th, 2011, 11:38 AM
Would you be prepared to share that pinout?

TNC
July 29th, 2011, 01:00 AM
Yes, it is ISA compatible but the IBM PS/1 models 2011 and some 2121 don't have ISA connectors. Instead there is a 34 pin header to attach a very rare PS/1 Audio Card, so I used it.

It seems to be, that not all 2121 lack ISA slots. Mine got 2 or 3 (cant exactly remember). Look on the pictures (looked like mine, but mine was faster):
http://www.edv-und-radio-nostalgieservice.de/detail.php?name=IBM+PS%2F1+Mod.2121&dir=computer&dirid=1&id=1&ok=Ansehen

Great Hierophant
July 29th, 2011, 12:40 PM
Does the Card use IRQ and DMA? That takes up 3 pins, I/O R/W 2 pins, ALE 1 pin, OSC 1 pin and then there are at least 10 Address Pins and 8 Data Pins. +5v and GND make two more, and it probably requires a - volt.

nestor
July 29th, 2011, 01:16 PM
No, it doesn't use IRQ, DMA or OSC signals. If they are present in the proprietary connector, I couldn't identify them. It uses 10 address pins, 8 data pins, /IOR, /IOW, ALE, GND, +5v, +12v and -12v. Also uses an output pin that routes sound to the monitor, mixed with the PC-Speaker sound.

Great Hierophant
July 29th, 2011, 10:20 PM
Sorry, I thought I was asking about the IBM PS/1 Audio Card, which does use IRQ but not DMA and has no oscillator onboard. Your pin usage corresponds exactly to the Adlib card needs to use, except that the real card uses the OSC signal. I assume you also have IOR and IOW on your board.

nestor
July 30th, 2011, 12:33 AM
You are right, I missed the /IOR and /IOW pins (edited last post). As I couldn't identify the OSC pin in the PS/1 header, I made a 14.318 oscillator for the YMF262. This card is only a prototype, I think I can improve it and reduce greatly the numer of components used. I wired both output channels from the YAC512 but AdLib software only produces mono output, so one channel can be removed. If the OSC signal is present in the header and I can find it, the oscillator can also be removed.

About the IBM PS/1 Audio Card, I don't have any info about it. Does it allow to play digital samples like the Sound Blaster or only synth like AdLib?

Great Hierophant
July 30th, 2011, 09:18 AM
The IBM PS/1 Audio Card has similar functionality to the Tandy PSSJ sound chip found in the Tandy 1000 TL/SL/RL machines. It does not have FM synthesis, but the same TI PSG sound found in the TI SN76496 (3 square waves + 1 noise channel). It does have DAC that uses an IRQ but not DMA. See here for more info :
http://vogons.zetafleet.com/viewtopic.php?t=18327&postdays=0&postorder=asc&highlight=ps1%29.&start=20

I cannot tell from the discussion whether card uses the OSC signal or not, but I am guessing that it is likely.

nestor
August 15th, 2011, 10:21 AM
Thank you for the information. I found a clock signal in the 34 pin header but it is not the 14.318 ISA clock, it seems to be the system clock (10 MHz) because the OPL3 plays tunes in a lower pitch when feeded with this clock signal.

pl212
May 24th, 2014, 11:12 AM
Just following up on this... would you be interested in possibly sharing your design for the SoundBlaster clone? I know there are many of us with PS/1's who would enjoy trying to make one of them ourselves.

A separate project could be to produce the PCjr-based "PS/1 Audio Card" itself, since I can't imagine the chips would be all that expensive.

Great Hierophant
May 24th, 2014, 04:37 PM
http://ps1stuff.wordpress.com/ - Resource for the 2011 Technical Reference and other cool stuff. Only the 10MHz clock signal is sent to the connector to the PS/1 Audio Card and Joystick Adapter. The base frequency for the tone generators is 125KHz. The chip has divide by 32 and a divide by 2 stages in addition to the programmable 10-bit frequency divisor. The CLK signal in the PS/1 2011 is 10MHz, and that is the only oscillator-type signal on the connector for the but it is apparently knocked down to 8MHz before it reaches the sound chip or at the sound chip.

By contrast, the 3-voice sound chip in the PCjr. and Tandy 1000 use a 3.579MHz signal for input. The TI SN76469 has divide by 2, divide by 8 and divide by 2 stages in addition to the in addition to the programmable 10-bit frequency divisor. This would make the base frequency for the tone generators 111,860KHz.

The Adlib and Sound Blaster cards with Yamaha OPL2 and OPL3 chips use the 14.318180MHz signal from the OSC pin or an onboard crystal with that frequency. That frequency is divided by 4 before it reaches the chip. If you divide the 10MHz CLK pin by 4, you would get 2.5MHz, which is way too slow.

ssshake
June 9th, 2019, 07:48 PM
Thank you for the information. I found a clock signal in the 34 pin header but it is not the 14.318 ISA clock, it seems to be the system clock (10 MHz) because the OPL3 plays tunes in a lower pitch when feeded with this clock signal.

This is an old thread but if you would either post schematics and parts so I could build one that would be awesome. Or if you would be willing to build one to sell me I would be very interested. I love the 2011.