Interactive Connector Diagram
Click or tap any pin in the diagram below to inspect its signal assignment, electrical specification, and wire colour standard.
Click any pin to view its signal assignment, electrical spec, and wire colour.
Supported Systems / Found On — Retro Machine Hubs
This connector is used on the following retro computer systems. Click any colour-coded badge below to open its full board-level repair, diagnostic, and schematic Machine Hub:
Connector Specifications
Connector Type
23-Pin D-Sub Female (DB23F) on Amiga; DB23 Male plug on drive cable
Drive Selects
Pin 21 = /SEL1 (DF1:), Pin 9 = /SEL2 (DF2:), Pin 20 = /SEL3 (DF3:)
Power Outputs
Pin 12 = +5.0 V DC (250 mA continuous) | Pin 23 = +12.0 V DC (160 mA continuous)
Full Pin Assignment & Wiring Reference
| Pin | Signal Name | Direction | Electrical Spec / Role | Wire Colour / SCART / Adapter Target |
|---|---|---|---|---|
| 1 | /RDY (Disk Ready) | In | Active-Low Disk Ready / ID Bitstream input (to CIA-A PA5) | Shugart Pin 34 (/RDY) |
| 2 | /DKRD (Read Data) | In | Raw MFM Read Data input (to Paula Pin 37) | Shugart Pin 30 (/RDATA) |
| 3 | GND (0 V) | GND | Digital & Motor Ground Return | Black (Odd Shugart Pins) |
| 4 | GND (0 V) | GND | Digital & Motor Ground Return | Black |
| 5 | GND (0 V) | GND | Digital & Motor Ground Return | Black |
| 6 | GND (0 V) | GND | Digital & Motor Ground Return | Black |
| 7 | GND (0 V) | GND | Digital & Motor Ground Return | Black |
| 8 | /MTRXD (Motor On) | Out | Latched Motor Control signal (from CIA-B PB7) | Latch to Shugart Pin 16 (/MOTOR) |
| 9 | /SEL2B (Drive DF2:) | Out | Active-Low Select for second external drive (DF2:) | Cascade to next drive |
| 10 | /DRESB (Disk Reset) | Out | Active-Low System Reset output | Reset |
| 11 | /CHNG (Disk Change) | In | Active-Low Disk Change detect (to CIA-A PA2) | Shugart Pin 2 (/DSKCHG) |
| 12 | +5.0V DC | Pwr | +5.0 V DC Logic Supply (powers external Gotek directly!) | Red (+5V to Gotek Power) |
| 13 | /SIDEB (Head Select) | Out | Disk Side Select (Low = Upper Side 1, High = Lower Side 0) | Shugart Pin 32 (/SIDE) |
| 14 | /WPRO (Write Protect) | In | Active-Low Write Protect sensor input | Shugart Pin 28 (/WPT) |
| 15 | /TK0 (Track 00) | In | Active-Low Track 00 sensor input | Shugart Pin 26 (/TRK00) |
| 16 | /DKWE (Write Enable) | Out | Active-Low Write Gate output (from Paula Pin 39) | Shugart Pin 24 (/WGATE) |
| 17 | /DKWD (Write Data) | Out | MFM Write Data pulse output (from Paula Pin 38) | Shugart Pin 22 (/WDATA) |
| 18 | /STEPB (Step Pulse) | Out | Active-Low Stepper pulse output | Shugart Pin 20 (/STEP) |
| 19 | DIRB (Direction) | Out | Step Direction output (Low = Inward, High = Outward) | Shugart Pin 18 (/DIR) |
| 20 | /SEL3B (Drive DF3:) | Out | Active-Low Select for third external drive (DF3:) | Cascade |
| 21 | /SEL1B (Drive DF1:) | Out | Active-Low Select for first external drive (DF1:) | Shugart Pin 10 (/DS0 on Gotek!) |
| 22 | /INDEX | In | Active-Low Index Pulse input (to CIA-B /FLAG) | Shugart Pin 8 (/INDEX) |
| 23 | +12.0V DC | Pwr | +12.0 V DC Motor Supply | Yellow (+12V) |
Booting an Amiga 500 from an External Gotek on DF0: (Boot Selector)
Every classic Amiga includes a rear 23-pin D-Sub female socket (DISK DRIVE) controlled by Paula (8364) and CIA-B (8520). Because Pin 12 provides +5 V DC (250 mA) and Pin 23 provides +12 V DC, an external Gotek floppy emulator runs directly off the DB23 port with zero external power bricks!
- Why an External Gotek Adapter Needs a 74LS74 + 74LS38 (or FlashFloppy interface = amiga): On the Amiga bus, the Motor signal (Pin 8 /MTRXD) is latched on the falling edge of /SEL1B (Pin 21), and AmigaOS identifies whether a 3.5" DD drive is attached by clocking a 32-bit 0xFFFFFFFF ID sequence onto Pin 1 (/RDY) while toggling /MTRXD! FlashFloppy on a Gotek generates this Amiga drive ID natively when interface = amiga is set in FF.CFG!
- Booting from External Gotek as DF0:: Install a socketed DPDT /SEL0 <-> /SEL1 Boot Selector under the 40-pin CIA-B (U8 on A500) chip to swap internal DF0: and external DF1: with the flick of a switch!