Are there standard DIN pinouts for cassette and video ports on early Japanese 8-bit computers?

Question

I have several different Japanese 8-bit computers, and they use similar DIN connectors for video and cassette I/O:

• Composite video: 180° 5-pin DIN: Fujitsu FM-7, NEC PC-8001mkII
• Color TTL (digital) RGB/RGBI video: 8-pin 270° DIN: Fujitsu FM-7, NEC PC-8001mkII
• Cassette: 270° 8-pin DIN: Fujitsu FM-7, NEC PC-8001mkII, NEC PC-6001

These are just ones I have examined myself; I have seen various other examples on the net that look as if they also output the above signals out the same jacks.

Is there a common (even if informal) standard for any or all of these, or do Japanese 8-bit computers frequently use the same 5-pin and 8-pin DIN connectors for these signals but with different pinouts?

I am interested just in the signals listed above: cassette audio, composite video and TTL (digital) video. (I believe that would restrict this mainly to pre-MSX and MSX1 computers.) Standards for the monitor side of the connection or analogue RGB signals outside the scope of this question, unless they have a direct bearing on the connectors/signals above.

Answer 1

[This is a community wiki post. However, if you don't have enough reputation to edit it, or just don't feel like doing the work, feel free to post a comment on it linking to the source of a pinout that's not yet here and I will add it to the post --cjs.]

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The page OLD Hard　旧機種情報 >>Connecter Infomation　ケーブル情報 (Japanese) has a lot of information on various cables for Japanese computers, including a summary table at the bottom of that page covering CRT, keyboard, mouse, CMT (cassette), FDD and power (電源) connectors for 36 different computers. This information should be integrated into what's below.

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This won't help with determining if there are any formal standards, but we can at least figure out if there are informal/accidental standards by looking at actual machines. MSX1 seems to be fairly consistent (excepting analogue RGB, which we're not covering here), so between that and the pre-MSX computers there aren't all that many of them. The listings below are in approximately chronological order of release.

In this answer we use the standard pin numbering, below looking in to the female jack on the computer. Note that some references are different, in particular some that give a numbering marked "male" are actually looking at the side of the connector you solder, which gives the same numbering as below. But check the reference carefully!

       ∪                 ∪
                      7     6
  3         1       3    8    1
    5     4           5     4
       2                 2

The critical signals to make the interface work are in CAPS below; "extra" signals that shouldn't harm operation if left unconnected are in lower-case.

Cassette

Verdict so far: very standard.

                     1      2      3      4      5      6      7      8
NEC PC-8001         GND    GND    GND    REC    PLAY   REM+   REM-   GND
NEC PC-6001mkII     cmt1   cmt2   GND    REC    PLAY   REM+   REM-   GND
Fujitsu FM-77       GND    GND    GND    REC    PLAY   REM+   REM-   GND
Panasonic JR-200    GND    GND    GND    REC    PLAY   REM+   REM-   GND
MSX Standard        GND    GND    GND    REC    PLAY   REM+   REM-   GND

Notes:

• Cables almost invariably connect only pin 2 to sleeve on record/play plugs, 4/5 to tip on rec/play, and 6/7 to ring/tip on remote, leaving all other pins unconnected.
• There are a few exceptions to the standard for the MSX CMT interface. Most of them use a 5-pin port, and so are obviously different. It's not clear if the Frael Bruc 100, a not-quite-MSX computer, uses an 8-pin port, but at any rate it's Italian, not Japanese.

Sources: PC-8001 CMT, PC-6001mkII CMT, FM-77 CMT, JR-200 CMT, MSX CMT.

Composite Video

Verdict so far: two standards, one for non-MSX, one for MSX.

                     1      2      3      4      5
NEC PC-8001         ???    GND    COMP   ???    ???
Fujitsu FM-77       2MHz   GND    COMP   hsync  vsync
Sega SC-3000        audio  GND    COMP   gnd    gnd
MSX Yamaha/Victor   sound  GND    a/v+5  nc/rf  COMP           

Notes:

• The MSX comp used by Yamaha and Victor may not be an MSX-defined standard. It's incompatible with other systems listed here. The a/v+5 is used as a control signal to JP-21 (and possibly SCART) connections to set the aspect ratio.
• The Sega Master System/Mega Drive 8-pin video connector is also compatible with a 5-pin composite video cable using 2:GND and 3:COMP.

Sources: Sources: PC-8001 comp, FM-77 comp, SC-3000 comp, MSX comp.

Digital RGB Video

Verdict so far: very standard.

                     1      2      3      4      5      6      7      8
NEC PC-8001         vcc    GND    14Mhz  HSYNC  VSYNC  RED    GREEN  BLUE
NEC PC-8801         +12V   GND    ?      HSYNC  VSYNC  RED    GREEN  BLUE
NEC PC-6001mkII     14MHz  GND    ccont  HSYNC  VSYNC  RED    GREEN  BLUE
Sharp MZ-700        video  GND    csync  HSYNC  VSYNC  RED    GREEN  BLUE
Fujitsu FM-7        +12V   GND    2MHz   HSYNC  VSYNC  RED    GREEN  BLUE
Panasonic JR-200    vblank GND    comp.  HSYNC  VSYNC  RED   GREEN  BLUE
MSX Digital         +12V   GND    n/c    HSYNC  VSYNC  RED    GREEN  BLUE
Sharp MZ-800        i      GND    unused HSYNC  VSYNC  RED    GREEN  BLUE

Notes:

• The NEC PC-6001mkII ccont signal is the 色相制御信号 or RGBI intensity bit.
• The Sharp MZ-700 RGB scan has been corrected by hand to reverse the original 3:HSYNC and 5:CSYNC description, which was presumably a typo. The MZ-800 RGB source also gives an MZ-700 pinout that matches the correction.
• National/Panasonic JR-200 includes DIN-5-compatible composite color output on the same DIN-8 connector used for DRGB.
• Warning: The MSX RGB pinout above applies only to those MSX computers that use digital RGB output, which is very few (Fujitsu FM-X, Pioneer PX-7, PX-V7 and PX-V60 according to the source). Most MSX computers seem to use analogue RGB outputs on 8-pin connectors, which are not compatible with digital and vary in the pins they use for which signals.

Sources: PC-8001 RGB, PC-8801 RGB, PC-6001mkII RGB, MZ-700 RGB (p.19), FM-7 RGB, MSX RGB, MZ-800 RGB.

Answer 2

Is there a common (even if informal) standard for these,

No, they have been different from the beginning. Not even the ubiquitous MSX standard could establish a unified connector and even less a pinout.

In later years SCART/JP21 established a common use by market force, as it became a standard for TV sets in Japan and large parts of Asia. Still, compatibility was often reached by supplying a cable to connect a computer's proprietary plug to JP21 required by standard monitors/TVs.

or do Japanese 8-bit computers frequently use the same 5-pin and 8-pin DIN connectors with different pinouts?

Not only that, but they also use both versions of the DIN 45326 type 8 connector. 8A with 45° (also called 270°), but also type B with 41° (sometimes marked as 262°) - like the most beautiful of all MSXes, the Yashica YC-64.

Mechanically it's down to two main connectors:

• DIN 45326 type 8A
• SCART/NFC 92250 (only the connector)

With the DIN connector, next to all manufacturers had their own pinout. Some even changed between machines, as Panasonic did. They not only differ in signals present (RGB or YUV, sync on green, separate sync, combined sync, ...), but also in where they are placed (FM-X has +12V on pin 1, while Sanyo puts blue on 1).

The situation changed a bit after Japan adopted its version of SCART with the TTC-3/CPE-1201 standard. In Japan and Korea, it's usually called/labeled RGB-21, while outside (in Europe at least) JP-21 is the common name. While using the 21 pin SCART connector, the signal assignment is completely different.

De facto standardisation on the monitor/TV side happened in the mid-1980s when Japanese (and later Korean) manufacturers offered RGB (and later S-Video) input by default via JP21 connectors. In the late 1980s next to every Japanese home computer was sold either with a proprietary-to-JP21 cable, or newer machines already had JP21 built-in, so standard cables could be used.

Note that this is only true for machines for Asian markets. Units designated for Europe (like Sony HB-G900) had fully SCART compatible connectors on the back.

Bottom Line: JP-21 may be the closest answer here. It did, beginning in the mid-1980s, clean up the CRT side, but only in part replaced proprietary connectors on the console side. And it's not a DIN either.

Answer 3

There's a seller on Yahoo Auctions in Japan named michael_torojirou who makes cables for pre-90s computers. Over the last several years has sold a lot (several thousand, from the looks of it) of them with consistently good feedback, so it's likely that they work.

From his offerings for cables that connect 8-pin DIN digital RGB outputs to various kinds of monitors, we can see that the same cable is used for a wide variety of computers, indicating that these outputs are fairly standardized, even beyond the early 8-bit computers and MSX1.

Some examples:

MZ/PC-8801/8001/6001/6601/FM-7 to "RGB21" (i.e., the JP-21 variant of SCART). There's obviously digital-to-analogue RGB conversion circuitry in this cable because most of the computers he discusses have only digital outputs, and he's tested it with an analogue RGB display (Sanyo CMT-A14F1G) and several up/down-scalers. He lists this as usable with:

• Fujitsu FM-8、FM-7、FM-NEW7
• SHARP MZ-700/1500/2200/2500 (2500 at 16 colours, 15 KHz only)
• Casio FP-1100
• NEC PC-6001mk2、PC-6601/SR、PC-8001mk2/SR
• NEC PC-8801mk2 series digital 8-pin ouput (8 colours)
• NEC PC-9801 series digital 8-pin output (8 colors at 15 KHz low resolution)

MZ/PC-8001/6001/6601/FM-7 to DB-15 (not DE-15), for monitors with a 15-pin analogue RGB input. It seems basically the same as the cable above with a different monitor-side connector, and supports the same set of computers as above.

MZ/PC-8001/6001/FM-7三菱液晶MDT221WG/MDT242WG/RDT202WLM to DE-15. This seems to be for monitors like the Mitsubish [MDT242WG] that support analogue RGB at 24 kHz. It's been tested to work with:

• SHARP MZ-700, 1500 (startup screen), 2500 (several games; 16/8 colours only)
• Fujitsu FM-7, FM-NEW7 (several games)
• Casio FP-1100 (startup screen)
• NEC PC-6001mk2 (startup screen; PC60/PC66 16 colors not supported)
• PC-8001mk2 (startup screen; 40-cols not supported)
• PC-8801mk2FR (several games; 24 KHz)

He goes on to say that this is supposed to work with (I guess some) MSX2 computers and game consoles as well.

So it seems that there is a fairly standard pinout for digital RGB on 8-pin DIN connectors for early Japanese 8-bit computers.

Answer 4

I'm not sure if this is the right place to to mention this, but I confirm the outputs mentioned in the question (and reverse-engineer ones I'm not sure of) with this breakout DIN connector that I made:

This allows me to bring the signals on to a breadboard where I can 'scope them out, cross-connect them to a more standard video cable into a monitor, and so on.

The pin to wire colour assigment that I use is designed to be reasonably mnemonic for the (informal) standard for 8-pin DIN RGB video on Japanese 8-bit computers as described in the community wiki answer, though this of course can be used for CMT (cassette) ports as well:

1-Orange  2-Black   3-Yellow  # [V+/audio], GND, [clock]
4-White   5-Grey              # hsync/vsync (usu. grey/black); MIC/EAR
6-Red     7-Green   8-Blue    # TTL RGB; 6/7 cassette relay

(A similar breakout could be made for 5-pin ports.)

Note that the wires are kept quite short; this is important when using this for video since obviously this isn't coax.