A Sound Card Before Its Time

A mysterious full-length sound card recently arrived at the OS/2 Museum. It was clearly manufactured by IBM in 1985, and sports a 20 MHz Texas Instrument TMS32010 DSP (the DSP is the large black DIP chip near the lower left corner, not the ceramic gold cap chip).

A curious 1985 IBM sound card

The card has a FCC ID sticker, which is usually a good way to identify hardware:

A suspicious FCC ID sticker

The FCC ID is ANO95A6450611… which apparently does not exist. However, ANO9SA6450611 does. It is hard to say whether the typo is on the IBM card or in the FCC database. Either way, it’s an IBM FCC ID… from 1988. On a card made in 1985. If we discount time travel, there must be some other explanation.

The FRU P/N 15F8511 of the card leads to the IBM SpeechViewer adapter. The SpeechViewer was announced in late 1988, which matches the FCC ID, but not the card itself.

The IBM SpeechViewer was marketed as a PS/2 option—which somehow happened to only work in the ISA-based models 25 and 30. Because of course it’s an 8-bit ISA card. Why would IBM not make it a 16-bit card in 1988? Because the design is much older, going back to an era where a PC/AT with 16-bit slots was a rare high-end system.

The IBM SpeechViewer card appears to be more or less completely undocumented and only works with IBM’s custom SpeechViewer software. The SpeechViewer was designed for language therapists and one of its main purposes was to help deaf children learning to speak. This was accomplished by speech analysis software for therapists, and voice-controlled games for the young patients.

The SpeechViewer system was developed by the IBM Scientific Center in Paris, France and its development reportedly took about 10 years. That could explain why the card was made more than three years before it was sold, but maybe there’s more to it.

The IBM Voice Communications Option

Louis Ohland noticed that there was another similar card made by IBM, the Voice Communications Option. And that was announced in October 1985. The Voice Communication Adapter (VCA) was an 8-bit ISA card, with a list price of $1,200. Unlike the SpeechViewer, the VCA had audio and telephone jacks and was meant to be connected to a telephone network.

With appropriate software, the VCA could respond to voice commands, function as a voice-controlled keyboard, record and play back digital audio, synthesize speech from text, detect and produce dialing signals, and function as a 1,200 baud modem. All that in 1985.

The feature list is not unlike that of IBM’s 1990s Mwave adapters, and there are obvious similarities. The VCA (and SpeechViewer) is a DSP connected to a DAC and ADC. The DSP runs its own software and communicates with the host system.


Just how close is the SpeechViewer (SV) to the Voice Communications Adapter (VCA)? Very, very close. They in fact share the same PCB and only the connectors on the backplate are different. It’s clearly visible here:

The analog circuitry on IBM SpeechViewer

The VCA had three phone jacks on top, and two audio jacks on the bottom (J4 and J5). The pictured SpeechViewer has no phone jacks; instead there are two audio connectors, wired to the J4 and J5 locations. A few of the components on the PCB are not populated, but the analog section of the SpeechViewer contains a lot of heavy duty circuitry that is not common on sound cards but typical on equipment connected to the telephone network.

Without comparing with a real VCA, can we be sure that the SV is really almost identical? Yes we can, because IBM did publish a technical reference for the VCA. The logic diagrams are a perfect match, including the component labels.

Now the story makes much better sense. The SpeechViewer hardware is a slightly modified Voice Communications Option, equipped with audio jacks only and no telephony connectors. IBM did have the hardware in 1985. The SpeechViewer was fairly widely tested in hospitals and clinics around the world before it was announced. It was clearly the SpeechViewer software that was under development before 1988, not hardware.

How It Works

The SpeechViewer (and Voice Communications Adapter) is, as previously mentioned, a DSP-based sound card.

IBM SpeechViewer digital section

The TMS32010 DSP could run at 20 MHz (on the SV it runs at 19.968 MHz, a frequency evenly divisible by 768). On the left-hand side are Toshiba SRAM chips, all 2KB capacity. There are eight 55ns chips for a total of 16KB data memory, and two 45ns chips for 4KB of code memory (all using 16-bit words from the DSP’s perspective). It should be understood that this was extremely fast memory at the time. The SRAM chips appeared in Toshiba’s 1983-4 catalog and were massively faster than other SRAM/DRAM chips which typically had 100-300ns or more access time, and much longer cycle time (for the SRAM chips, it’s 45/55ns access and cycle time). The SRAM no doubt significantly contributed to the original $1,200 VCA price tag.

The DSP could execute one instruction in 200ns (5 million instructions per second). That included a 16-bit × 16-bit multiply. The TMS32010 supported 16-bit fixed-point math.

The SpeechViewer sports two AMD Am6012PC 12-bit DACs. One of them is used with an AMD Am2504PC successive approximation register to function as an ADC. The SV and VCA work at 8 or 9.6 kHz sample rate with 12-bit signed samples. There is only a single audio channel, no stereo.

The card does not use any DMA, only interrupts and shared memory. The 20KB of RAM on the card can be mapped into an 8K window in the host’s address space, selecting between lower or upper half of data memory, or code memory.

There is no firmware on the SV or VCA; the DSP code must be uploaded by the host before the DSP is brought out of reset.


There is rather obvious similarity between the 1985 VCA/SV and the 1989 IBM M-ACPA. The M-ACPA uses the exact same basic architecture with a newer TI DSP and differently organized SRAM (it has 4K dedicated sample memory and 16K data/code memory). And of course the M-ACPA can do 16-bit stereo at 44.1 kHz.

Not coincidentally, the refreshed IBM SpeechViewer II package required an M-ACPA card instead of the old model.

As mentioned above, the IBM Mwave is another obvious successor of the VCA/SV and M-ACPA.

Is It a Sound Card?

No contemporary literature calls the SpeechViewer hardware a sound card, although that’s exactly what it is. The term “sound card” probably wasn’t used until about 1989.

The IBM VCA must have been one of the earliest PC audio recording and playback adapters, although it was designed primarily for telephony and the DSP gave it capabilities that went far beyond what early sound cards could do.

In 1985, PCs were severely limited by available RAM and hard disk space (if they even had a hard disk; the VCA did not require one). Hard disk recording was not very feasible and the 8088 was not very suitable for digital audio processing—that’s after all why IBM used a DSP on the cards, because the DSP had significantly higher number crunching power than even a 286.

The VCA is older than the 1987 Covox Speech Thing, which was the first widespread PC digital audio accessory. It supported 8-bit digital output only, no sampling. A completely different class of device, the Speech Thing also cost well under $100, not over $1,000 like IBM’s hardware.

What Is Missing?

So what’s missing to use the SpeechViewer as a sound card? Well… everything. The IBM-provided software, which includes the DSP firmware. The VCA/SV significantly predates modern multimedia environments, so there is no such thing as a Windows 3.1 driver for it.

The card came without any software, so there’s not much to do with it. Armed with the VCA Technical Reference it would be possible to write something, but developing the DSP firmware from scratch might be a little tricky.

VCA or SV software, anyone?

This entry was posted in IBM, PC history, Sound. Bookmark the permalink.

20 Responses to A Sound Card Before Its Time

  1. Fernando says:

    Found a commercial, I think it is for this card, not much info:

    It’s not mentioned by name, but could give some context:

    Curiously the IBM Voice Communication Adapter was supported in “IBM 3270 Personal Computer AT” and “IBM 3270 PC (5271)” now I wonder what would one do with such configuration.

    In a site that was mentioned in a comment before there is a “IBM Voice Communications Adaptor AT Diagnostic Disk”, you could at least try that.

    Could be interesting make a driver for that card. Probably every time that a sound is played every other thing stops.

  2. Michal Necasek says:

    The 3270 AT and PC were basically standard ATs and PCs that also functioned as a 3270 terminal. It was a regular PC with extra hardware, but marketed as a separate model.

    Yes, there was a VCA diagnostic disk, but I don’t have that.

    The card was actually very advanced, and probably had a lot more computing power than the typical PC/AT. It could do quite a bit of processing without involving the CPU.

  3. Richard Wells says:

    Earlier sound cards were typically referred to in the trades as voice mail cards. See Infoworld Oct 29, 1984 for a list. PC Magazine Jan 17, 1989 has a comparison review of the IBM VCA and 5 competitors. IBM’s card did not do well.

    I am fairly certain I was programming a slightly later version of the Natural Microsystems card. I doubt its phoneme based sound generation would have worked well as a music card.

    I remember IBM’s VCAPI was very rudimentary but thirty year old memories can be wrong. An online reference explaining some of how it works can be found in a patent for voice notes with Display Write 4.

  4. Cloudschatze says:

    It seems the SpeechViewer card may be a contemporary of the NEC SAR-10:

    Regarding this though:

    “…the 1986 Covox Speech Thing, which was the first widespread PC digital audio accessory.”

    Wikipedia gets an “F” for this oft-cited bit of Internet-era misattribution.

    The Speech Thing was released in “late 1987,” according to Covox:

    Which can be further narrowed down to December 18, 1987, given the Covox-provided, first-use-in-commerce date:

    I should probably update the Wikipedia article or something… 🙂

  5. Michal Necasek says:

    In 1989, the VCA was quite old so I’m not surprised it compared poorly to competitors. And yes, telephony appears to have been the first widespread usage for hardware that was later called sound cards. I assume that the term “sound card” came into use with hardware designed (or at least sold) primarily for games, but I don’t know that.

  6. Michal Necasek says:

    I fixed the date in the article, thanks for the correction. Yeah, it’s Wikipedia… if there’s no citation, it’s probably an error or a lie.

    So the Speech Thing came out at more or less exactly the same time as AdLib. One for music, one for digital audio. The IBM VCA is much older but also a much more advanced design. Which it had to be when it needed to do something useful on an 8088-based PC.

  7. Michal Necasek says:

    About the NEC SAR-10, those were the days. Not just the card but all the complex chips were designed and manufactured by NEC.

  8. pdw says:

    There are VCA diagnostic disks on Vetusware.

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  10. js2 says:

    Interesting. This card is similar in many ways to the Novation Apple-Cat II which was available by 1981.



    I can’t find any FCC registration for the Apple-Cat II either.

  11. techfury90 says:

    I am *zero* percent surprised that NEC would have made a similar card. I’ve read their CEO at the time’s autobiography (“Computers and Communications” by Koji Kobayashi), and it mentions that NEC’s top research project in 1985 (when the book was written) was a telephone that could do real-time translation between Japanese and English. It was viewed as decades off, even by NEC leadership, but they were investing in it heavily.

  12. techfury90 says:

    NEC was also probably the single most vertically integrated personal computer vendor in history. If you look at 80s-era PC-98s, almost every IC was from them, save for the Intel CPU (and not even that for V30 machines!) and Yamaha FM synthesizer. FDDs? In house. Key switches in the keyboards? Yep. HDDs? Yep. Monitors? Oh, they even made the CRT tube itself!

  13. Richard Wells says:

    The earliest low cost (about $100) PC sound type card I can find a reference to is the Artic Synphonix released late 1984 which moved from the Apple II. Covox had the C64 version of Voice Master at the time but took a few years to get a PC version ready. Artic moved their speech tools upmarket to focus on business and educational screen readers.

    TI had the Speech Development System which was another early 8-bit PC card. I can’t tell which was first because the TI reference with pictures of many of the early TMS 32010 boards was dated in 1986. Not very good quality pictures making it difficult to compare layouts on the TI, IBM and NMS cards to see if all were based on a reference design.

    A more specialized audio early PC audio device would be the MCS AUDIODATA/IBM PC keyboard. https://nfb.org/Images/nfb/Publications/bm/bm85/bm8507/bm850712.htm

    http://www.afb.org/info/living-with-vision-loss/using-technology/interviews-with-technology-pioneers/assistive-technology-timeline/1235 might give a good over view of how speech developed and dropped in price which rather parallels how affordable music sound cards became viable.

  14. MiaM says:

    If it were designed in Paris, it could very well had been in use in french speaking territories long before it got a FCC ID.

    My general impression is that there has been a rather large barrier between french technology and most other parts of the world.

  15. Chris M. says:

    The French was the undisputed kings of technology protectionism, at least with regards to TVs. Witness the 819 line System E/F TV broadcasts, SECAM color, and the SCART plug. All originated from France and required in order to sell TVs there.

    I’d hope NEC used their tubes in their monitors. They were the best one could buy! Nothing beats an old NEC Multisync or Multisync II for video compatibility.

  16. MiaM says:

    I’d say that the real protectionism were inverted video modulation and AM modulated audio on the TV’s. That’s what made french transmissions really incompatible with the rest of the world. Compare with West v.s. East Germany where you’d get a black/white picture will good sound if you recieved transmissions your TV weren’t supposed to recieve.

    Except for the questionable mechanical quality, the SCART connector is a blessing that all of Europe had and gave the TV’s superior possibilities as a computer monitor. Too bad that S-video hadn’t surfaced yet when the SCART standard was set though, so that became a kind of add-on hack.

    PAL were partially made as a technology protectionism too. Also UK and Ireland used 6MHz picture-sound carrier distance while the rest of West Europe plus East Germany used 5.5MHz. The dutch magazine Elektor/Elektuur suggested hooking up 6MHz filters simply in parallell to the 5.5MHz filters in a TV set to be able to recieve both UK and continental transmissions.

    Btw at least some of the european manufacturers outside France did have SCART but couldn’t bring them self to use a french name, so it were called “PERITEL” or “EURO-AV” or similar.

    In vintage computer forums I see all theese non-european people discussing different converters and other stuff to hook up their 80’s home computers, while we in Europe just make a cable or at most use a bunch of resistors to convert TTL levels to analogue levels, and use the RGB input of the SCART socket.

  17. Michal Necasek says:

    This card was designed by IBM France, and from what I can tell the system was not developed for French first and English later. It was in development for a long time because it was a research project.

  18. Phenella Laurence says:

    So, would it play with perhaps this somg ?

  19. Michal Necasek says:

    I haven’t read anything about IBM using the VCA/SV for music. Then again with the DSP, I don’t think there’s any reason it couldn’t be done.

  20. Richard Wells says:

    IBM Story Board Plus software split the functionality using both the music feature card (for music) and the voice communications option (for speech). Nothing prevented the recording of music as speech but the playback from the VCA would garble most music.

    TI had an app note explaining how to make the TMS 320xx into a music synthesizer but I think the IBM VCA card lacked the few components necessary to do it. Dead link now alas.

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