15 pin highdensity D-SUB female connector at the computer.
15 pin highdensity D-SUB male connector at the cable.
The Macintosh Portable (1989) includes a 15-pin high-density D-shaped external video connector that is fundamentally different from the standard Apple DA-15 analogue RGB connector found on other Macintosh models. Rather than carrying separate red, green, and blue video signals with sync lines, this port exposes the internal flat-panel display data bus directly — an 8-bit parallel digital interface (FPDATA[0–7]) together with a frame-sync signal, a display clock, backlight control voltage, +5 V supply rails, and a direct connection to the main battery voltage. The governing specification is documented in Chapter 12 (Table 12-9 and Figure 12-6) of Apple’s Guide to the Macintosh Family Hardware, Second Edition (1990). Because the signal set is incompatible with all other Apple video hardware, the connector should never be connected to a standard Macintosh DA-15 monitor or adapter.
| Pin | Signal | Description |
|---|---|---|
| 1 | FPDATA(0) | Flat-panel display data bus (bit 0) |
| 2 | FPDATA(1) | Flat-panel display data bus (bit 1) |
| 3 | +5V | +5 volts DC |
| 4 | FPDATA (2) | Flat-panel display data bus (bit 2) |
| 5 | FPDATA(3) | Flat-panel display data bus (bit 3) |
| 6 | FPDATA(4) | Flat-panel display data bus (bit 4) |
| 7 | GND | Ground |
| 8 | +5V | +5 volts DC |
| 9 | GND | Ground |
| 10 | FPDATA(5) | Flat-panel display data bus (bit 5) |
| 11 | FPDATA(6) | Flat-panel display data bus (bit 6) |
| 12 | FPDATA(7) | Flat-panel display data bus (bit 7) |
| 13 | BATTVOLTAGE | Direct connect to main battery |
| 14 | FLM | Flat-panel new frame sync |
| 15 | CL2/ | Flat-panel display data clock |
Notes
The physical shell is a 15-pin high-density D-type (sometimes labelled HD-15), identical in form to the DA-15 used for analogue RGB video on other Macintosh computers of the same era, but the signals are entirely different. This connector must not be connected to a standard Apple DA-15 video monitor, a DA-15 video card, or any VGA-to-Mac adapter — doing so risks damage to both the monitor and the Portable’s logic board. The BATTVOLTAGE line (pin 13) carries unregulated main-battery voltage directly to the external display panel; no current-limiting circuitry should be assumed. The two +5 V supply pins (3 and 8) and two ground pins (7 and 9) are provided in pairs to reduce connector resistance at the supply rails. This connector was used to drive an optional external flat-panel display accessory and was not intended as a general-purpose external monitor port.
Signals
- FPDATA(0–7) — 8-bit parallel flat-panel display data bus; bits 0–7 appear on pins 1, 2, 4, 5, 6, 10, 11, and 12 respectively
- +5V — regulated +5 VDC supply for the external display panel (pins 3 and 8)
- GND — ground reference (pins 7 and 9)
- BATTVOLTAGE — direct connection to the Portable’s main battery; supplies unregulated battery voltage to the external display backlight or panel circuitry
- FLM — frame-level sync (also known as VSYNC or FSYNC in related documentation); signals the start of a new display frame
- CL2/ — flat-panel display data clock (also referred to as FCLK); active-low clock signal that latches data on the FPDATA bus into the display panel
References
- Guide to the Macintosh Family Hardware, Second Edition (1990) — Apple Computer, Inc. / Addison-Wesley; Table 12-9 and Figure 12-6 document this connector
- Apple Ports and Pinouts (Service Source K reference) — Apple Computer, Inc.; confirms FPDATA[0–7], +5V, GND, BATTVOLTAGE, FSYNC, and FCLK assignments