Photos of DMS-1 Cartridge and PCB

By jdmcs

Rookie (22)

Аватар пользователя jdmcs

21-01-2019, 04:14

Apparently, I under-estimated the desire of forum members to see inside of MSX cartridges in a previous post regarding an apparently rare DMS SRAM cartridge that I purchased in a three cartridge lot on eBay. I paid a total of AUS $114.09 (AUS $70.89 winning bid + AUS $43.20 international shipping to the US) for the aforementioned SRAM cartridge, the DMS-1 cartridge, and a YRM-102 cartridge.

Therefore, without further ado, here is a quick peek inside the "D.M.S. 1 Real Time Sequence/Recorder" cartridge for the Yamaha CX5M Music Computer (equipped with the SFG-01)...

The front, top, and rear of the cartridge are rather unassuming. Other than the rather cool looking DMS logo (bonus points given by me for finding the logo totally retro for an 80's indie MSX publisher, even if it seems a bit old today), the label is totally unassuming.

The cartridge snaps together, and holds a rather generic-looking PCB inside. To keep the label intact, I actually broke two pins at the top of the plastic when I unsnapped the plastic. (Oh, well...) I then immediately freak out when I see an EEPROM without a protective label:

Also, well played, whomever wrote IC in a pencil on that chip...

That's a bare PCB by any standards with only two components! The EEPROM is a Hitachi HN4827128G-25 -- I believe this is a 16kb x 8 ROM with a 250ns access time.The other component is a capacitor, which had two lines of text printed on it, the first being "1" and the second being "35+".

Interestingly enough, the EEPROM is at location ROM1, with an unpopulated ROM2 location presumably for larger cartridges assembled by the same contract manufacturer. (I presume DMS was not large enough to make their own cartridges, especially given how the SRAm cartridge was obviously not designed by DMS.)

The back of the PCB is even less interesting than the front:

Unlike the SRAM cartridge, there's no indication of who the contract manufacturer might have been. However, given the generic nature of the PCB, I suspect that it might have been manufactured by a company that also contract manufactured other third-party MSX cartridges.

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By jdmcs

Rookie (22)

Аватар пользователя jdmcs

21-01-2019, 04:45

By the way, I realize many folks are emulating MSX computers these days due to the difficulty in obtaining and maintaining vintage computer hardware. However, I am trying to acquire certain hardware and software items focused around the Yamaha CX5m due to a certain je ne sais quoi (cue vintage TV show reference at 5:41) of generating music on the actual vintage platform.

So if enough folks enjoy this post, I'd be glad to post photos looking into other hardware-related items for the CX5M... including those of the CX5M itself.

(And yes, I learned all of the French I needed to know from Due South.)

By jdmcs

Rookie (22)

Аватар пользователя jdmcs

21-01-2019, 05:58

Does this cartridge work? Yes! Here are a few photos additional photos for documentation.

This cartridge reports as version "1C":

By "Abdul H. Ibrahim":

(Yes, I've already private messaged dms1guy to see if he would comment on the SRAM cartridge post.)

With a "Registry Number" of 851001001 (I presume this is a Brittish thing):

(By the way, if this cartridge is inserted into a CX5M with an SFG-05, nothing happens -- the system boots to the BASIC prompt as if no cartridge was inserted.)

By rderooy

Paladin (686)

Аватар пользователя rderooy

21-01-2019, 08:40

Since you did not mention it... GenMSX has a link to the manual

By yzi

Champion (444)

Аватар пользователя yzi

21-01-2019, 19:44

Do you know which musicians, composers or arrangers used the DMS-1, and for what kinds of productions? What external gear, synthesizers, samplers, etc. was it used with?

By RetroTechie

Paragon (1563)

Аватар пользователя RetroTechie

21-01-2019, 23:44

That's an EPROM, not an EEPROM. The 2nd E is reserved for EPROMs which are erased using electrical means only (and thus come without a window). With a window it's erasable using short-wavelength (around 250 nm) UltraViolet light. Don't fret about a label over the window: in full sunlight erasure can take weeks, under ambient indoor light much, much, much longer. But yes with enough patience erasure may occur & this chip is old so better not tempt fate... Normally cartridge box shields the chip from light.

Indeed it's 128 kbit (16K x 8 bits), and here it'll occupy 4000-7FFFh memory range from slot it's inserted in - solder blob to cartridge pin 1 tells you this.

jdmcs wrote:

Also, well played, whomever wrote IC in a pencil on that chip...

Not "IC" from integrated circuit, but "1C" = version number (see screenshot you provided below). Pretty common to write version numbers like that on (E)PROMs using whatever is at hand - helps prevent sticking them in places where they don't belong, or shipping product with outdated versions in it.

Is this software dumped already?

By jdmcs

Rookie (22)

Аватар пользователя jdmcs

22-01-2019, 01:58


That's an EPROM, not an EEPROM.

I was suffering from EEPROM on the brain last night.


Is this software dumped already?

Looks like has a version of DMS-1 posted, but I'm not sure which version they have.

By mars2000you

Enlighted (6564)

Аватар пользователя mars2000you

22-01-2019, 02:24

jdmcs wrote:

Looks like has a version of DMS-1 posted, but I'm not sure which version they have.

It's version 1C (offset 1473H of the ROM)

DMS-2 is also available on this site.

By Mork

Resident (49)

Аватар пользователя Mork

27-06-2022, 17:13

If the Sequenzer/Recorder has no RAM at all, how many notes/minutes will it be able to record?