Casio ROM Packs

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Picture of a ROM Pack installed in a PT-87 Keyboard

The Casio ROM Pack system was a method of storing music information, rather like modern-day MIDI files, on small, interchangable “cassettes” which plugged into a Casio keyboard, a bit like you might plug in a Flash memory card today.

The format first appeared in 1983, and is similar in many respects to the Yamaha Playcard system, which appeared at around the same time. Casio made a number of keyboard models throughout the 1980s and early 1990s that accepted ROM Packs. The most recent ROM Pack I have seen is RO-618K, dated 1993, so the format was in use for at least 10 years - a surprisingly long time.

As well as just listening to the music, ROM Pack keyboards had various training modes to teach you to play the tunes, most using flashing LEDs above each key to guide you - the precursor to the modern Key Lighting feature.

As their name suggests, they were read-only – you could buy various ROM packs with various tunes pre-loaded, but you could not record your own data to the packs. Casio did have a writable equivalent – the “RAM Pack” – but very few keyboard models supported the writable packs (in fact, the PT-50 is the only one I know of), and the packs themselves are extremely rare.

Thanks to a hand-written note on the back of a PT-82 manual I recently acquired, I now know that ROM packs retailed for £7.95 each at Cliff Owen Music in Seven Kings in around 1986. According to the Bank of England's Inflation Calculator, that equates to about £25 in 2020 - so ROM Packs were not cheap!
Sadly, Cliff Owen Music closed down some time around 2015, and its former site is now occupied by a mobile-phone-repair-cum-hardware shop, and a law firm.

ROM Packs seem to be very robust. Even after nearly 40 years, I have never come across a faulty ROM Pack. Even the apparently-fragile elastomeric (Zebra) contact strip seems very reliable, and I have never had to clean the contacts, even on ROM Packs which have clearly been mistreated. In contrast, Yamaha Playcards can easily be damaged, both physically and by exposure to magnetic fields, rendering them unreadable. Casio's system is definitely the more resilient format.

What Keyboards support ROM Packs?

The following Casio keyboard models support ROM Packs: PT-8, PT-50, PT-80, PT-82, PT-87, PT-88, PT-180, PT-280, PT-380, PT-480, PT-580, PT-680 MT-18, MT-28, MT-85, MT-86, MT-88, MT-800, MT-820, MT-830, CT-800, CT-805, CT-810, CT-840, SK-8, SK-8A, KS-03, KS-02 (not to be confused with the SK-2 which is a different keyboard with no ROM Pack support).

The Casio DH-280 and DH-800 Digital Horns (Wind Synthesizers) also take ROM Packs.

The technology was never licensed to any other manufacturer, but some ROM Pack keyboards were sold under the Realistic Concertmate brand in Tandy (UK) and Radio Shack (US) shops, but these were simply rebadged Casio models.

I was recently informed that a company called Liwaco (chiefly known for making hand-held LCD electronic games) also sold re-badged Casio keyboards in France, and possibly elsewhere as well. A number of these Liwaco clones were ROM Pack-compatible, and it appears that the ROM Packs themselves supplied with them were also rebranded as "Liwaco ROM," with a very different label design from Casio-branded ROMs. See this blog post about Liwaco's Casio clones.

The American piano manufacturer Baldwin also cloned some Casio keyboards, including the ROM-Pack-capable CT-810. This model was rebadged as the Baldwin Discoverer 60, and bundled with a clone of ROM Pack RO-551, labelled as Baldwin BRP-1.

Other manufacturers may also have cloned ROM Pack keyboards. The Russian company Electronica cloned the Casio VL-1, naming it the IM-46, so it seems likely they would have cloned other models as well, and there could be many others.

What ROM Packs were available?

I have created a List of Known Casio ROM Packs, based on information from a multitude of sources, some reliable, others not. It's almost certainly not complete, and probably isn't very accurate, but it gives an idea of the sort of music that was available on ROM Packs.

The most common ROM pack is the RO-551, entitled "World Songs." This contains four songs and seems to be the one Casio supplied with most of their ROM pack-compatible keyboards, so there are plenty of these around. Other ROM packs are actually quite scarce, and usually only appear on eBay when bundled with a keyboard.

What does the music sound like?

Different keyboard models render the ROM Pack music differently, but there are some audio examples on the List of Casio ROM Packs.

What's inside a ROM Pack?

Surprisingly little. It's just one IC (presumably a PROM) on a small PCB, with a couple of capacitors and an elastomeric (Zebra) contact strip. Most of the Pack is empty space. I think the pack was probably designed to be this size so that Casio could fit all the stuff required for the writable RAM Pack into the same package. The writable packs didn't seem to catch on, so we're left with a ROM Pack that could be roughly a quarter of the size it is. Of course, the marketing department probably had a large say in the dimensions as well.

To the right is a picture of a dismantled ROM Pack so you can see for yourself (click the image for a high-resolution version).

This particular pack (RO-551) contains a Panasonic MN6404 IC, but other packs may contain different ICs - I opened an RO-261 and found an OKI M5268. The PCB was also much thinner, but otherwise identical.

I have not been able to find data sheets for either of these ICs, and the only information I can find on the system is in the SK-8 Service Manual, and is very sketchy and leaves a lot of questions unanswered. Please let me know if you can help.