Philips PMDS / PM 4422 keyboard

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Philips PMDS / PM 4422 keyboard

I've done my research (including ABBA and Billy Joel) while cleaning a gorgeous 1982 Philips keyboard belonging to a PM 4422 computer.

KBD.news
Published March 9, 2023

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Let's set the tone for this rather long and media-heavy post with The Visitors by ABBA (1982). Hit play, continue reading, and you'll see in a minute why.

Background

This weekend I was cleaning a recently acquired Philips keyboard. I bought it the very second I spotted it on a local classified site, without knowing anything about this particular model. With apparent sings of pre-1984, pre-standard design it seemed unique and rare enough to fit into my collection:

Pic: Photo of the original listing

Photo of the original listing

It came without the terminal/computer, still, it was thrilling to disassemble and clean this relic while doing my research and watch the story unfold.

Research

Neither the sticker on the back (Philips NC 8700 817) nor the PCB (KB 817/01 - overwritten to 02 with a sharpie) provided any usable clue on the keyboard, at least nothing Google would appreciate.

Pic: Sticker on the back (Philips NC 8700)

Sticker on the back (Philips NC 8700)

Pic: On the silk screen: KB 817/01 overwritten by hand to 817/02

On the silk screen: KB 817/01 overwritten by hand to 817/02

In my desperation I searched for "Philips terminal keyboard" and, after endless scrolling, I came across some keyboards with a distinctively '70/'80 vibe and colorway, similar to that of my unknown Philips (PX-1000Cr, Philips P2000T).

And then there was this photo showing the same unmistakably weird layout with amber accents:

Pic: Source: DutchAudioClassics.nl

Source: DutchAudioClassics.nl

DutchAudioClassics.nl has a handful of write-ups on early CD mastering and production with some archive images. One step closer to the solution, but not there yet.

My keyboard is beige, while the housing of the otherwise identical keyboard in the photos is dark brown/grey. But a black and white photo features the white/light beige version:

Pic: Source: DutchAudioClassics.nl

Source: DutchAudioClassics.nl

My keyboard, in either brown or white housing, is in all those photos, unfortunately, without any usable reference to the computer.

Pic: Source: DutchAudioClassics.nl

Source: DutchAudioClassics.nl

By the way, that's why ABBA. The Visitors, the eighth studio album of the legendary Swedish pop group, was the first one released on CD (outside of Japan). The Compact Disk, a revolutionary new technology co-developed by Philips and Sony was introduced in 1979 as a prototype, but Philips had a hard time to put the concept and technology into mass production until 1982, when the first CDs finally hit the market:

The Visitors was one of the first records ever to be digitally recorded and mixed, as well as one of the earliest in history to be pressed on the CD format in 1982 (in terms of commercial release dates, it was predated by the Japanese release of Billy Joel's 52nd Street.) (source)

The CD mastering of these early albums in 1982, along with ABBA's, was done on Philips' rig called LHH 0400 CD-Master Recording System – the one in the photos above. And according to a sticker on the PCB, the Philips keyboard I held in my hands was manufactured in the same year.

Hm. Of course it would be too good to be true that I somehow managed to lay my hands on such a historic relic. At this point of my research it seemed more likely that Philips repurposed one of their contemporary computers available at that time, maybe a more generic workstation, for the LHH 0400.

A diagram in the LHH 0400 brochure marks the computer as LHH 0403 (no results), and the photos are too low-res to read the text above the screen. But Google Image Search saved the day by spitting out this Italian ad:

Pic:

(source)

So the computer in question is the Philips PMDS or Philips Microcontroller Development System. (In some other sources Philips Microprocessor Development System.)

This is the name of the framework, the whole ecosystem of various development tools I guess, the particular hardware in question is the PM 4421 (and PM 4422).

Pic: PMDS ecosystem.

PMDS ecosystem.

Strangely, being aware of at least three promising keywords (LHH 0400, PMDS, PM 4421/22), I still couldn't find much usable info on this piece of hardware, especially the keyboard. Nothing on deskthority, only a few BW photos in a German brochure:

Pic: PMDS I (PM 4421) – Note the dark housing.

PMDS I (PM 4421) – Note the dark housing.

As the name implies, the PMDS was a microprocessor development system – a system with the purpose of developing, programming testing, debugging, etc. microcontrollers. That's why in the photo above, you can see the adapters on offer for various processor families.

Earlier MDSs by Philips (PM 4400) were introduced in 1979, the same year the CD technology was announced. Basic price in Europe started at 14,000 GBP (Electronics & Power, 1979).

Pic: PMDS I, 1980

PMDS I, 1980

Being a microprocessor development system, not a home computer, explains the relative scarcity of both the hardware and the online resources covering it. Regardless, we are closing in:

Pic: PMDS II (PM 4422) – with white housing.

PMDS II (PM 4422) – with white housing.

This second photo shows the Philips PMDS II, an extended version with pretty much the same functionality (you could upgrade the I to II) but e.g. with multi-user support, more periphery options, etc.

Based on these photos it seems my keyboard (beige housing) belonged to a PMDS II…

Pic: My Philips PMDS II keyboard in all its glory

My Philips PMDS II keyboard in all its glory

… however, not for long, because another PMDS II ad lists it with another, much more meh, keyboard:

Pic: PMDS PM 4422 ad (source: retrocomputingforum.com)

PMDS PM 4422 ad (source: retrocomputingforum.com)

In Issue 10 of the RetroMagazine World, Alberto Apostolo has a short article entitled Philips Microprocessor Development System PDMS II listing some specs:

PMDS II specifications

CPU: Motorola 68000 (ref. Electronics & Power, p.6652, Oct, 1982)
RAM: 256 Kb (up to 1Mb)
Storage: 1 or 2 5.25" floppy disk drives, 1 Winchester HD of 5Mb or 21Mb (expandable with another HD up to 147Mb)
OS: UNIX (Bell Laboratories version)

Keycaps

But let's get back to the present and take a closer look at this gorgeous keyboard.

Both the layout and the keycaps are extraordinary:

Pic:

The keycap profile is unique, uniform, doubleshot in three colors (similar to the Philips P2000s):

Pic: CAP – the ultimate keycap legend

CAP – the ultimate keycap legend

Pic:

Huge stepped ETB (2x3->6u!), TAB (4u!) and "-" keys. All with a single stem, no dummy stems or stabilizers.

According to Marcin Wichary, "ETB" may refer to the End-of-Transmission-Block character.

Pic:

Lots of indicator LEDs with stylish cap-like housing.

Pic:

Switches

The switches are mushy and scratchy, just like you'd expect, I didn't want to desolder them so can't tell you the exact switch type. Stems similar to my Honeywell.

Pic:

Sorry, I'm definitely not going to desolder the switches, they are evil. As if they'd be designed specifically to drain your blood. And I have to say they are pretty effective in achieving that goal:

Pic: