Ampro Corporation Littleboard 550 SDD8, SDD6, SDD9, SDD5, SDD10, SDD4, SDD11, SDD3, SDD12, SDD2

Chapter 3			Hardware
	Pin #	Signal	Description
			All Task File operations occur in byte mode on the low order bus D0-D7, while
			all data transfers are 16 bit using D0-D15 to provide the disk data signals.
	4	SDD8	Secondary Disk Data 8 – Refer to SDD7 on pin-2 for more information.
	5	SDD6	Secondary Disk Data 6 – Refer to SDD7 on pin-2 for more information.
	6	SDD9	Secondary Disk Data 9 – Refer to SDD7 on pin-2 for more information.
	7	SDD5	Secondary Disk Data 5 – Refer to SDD7 on pin-2 for more information.
	8	SDD10	Secondary Disk Data 10 – Refer to SDD7 on pin-2 for more information.
	9	SDD4	Secondary Disk Data 4 – Refer to SDD7 on pin-2 for more information.
	10	SDD11	Secondary Disk Data 11 – Refer to SDD7 on pin-2 for more information.
	11	SDD3	Secondary Disk Data 3 – Refer to SDD7 on pin-2 for more information.
	12	SDD12	Secondary Disk Data 12 – Refer to SDD7 on pin-2 for more information.
	13	SDD2	Secondary Disk Data 2 – Refer to SDD7 on pin-2 for more information.
	14	SDD13	Secondary Disk Data 13 – Refer to SDD7 on pin-2 for more information.
	15	SDD1	Secondary Disk Data 1 – Refer to SDD7 on pin-2 for more information.
	16	SDD14	Secondary Disk Data 14 – Refer to SDD7 on pin-2 for more information.
	17	SDD0	Secondary Disk Data 0 – Refer to SDD7 on pin-2 for more information.
	18	SDD15	Secondary Disk Data 15 – Refer to SDD7 on pin-2 for more information.
	19	GND	Ground
	20	NC/Key	Not connected / Key pin plug
	21	SDREQ	Secondary DMA Request – Used for DMA transfers between host and drive
			(direction of transfer controlled by DIOR* and DIOW*). Also used in an
			asynchronous mode with SDACK*. Drive asserts SDREQ when ready to
			transfer or receive data.
	22	GND	Ground
	23	SDIOW*	Secondary I/O Write Strobe – Strobe signal for write functions. Negative edge
			enables data from a register or data port of the drive onto the host data bus.
			Positive edge latches data at the host.
	24	GND	Ground
	25	SDIOR*	Secondary I/O Read Strobe – Strobe signal for read functions. Negative edge
			enables data from a register or data port of the drive onto the host data bus.
			Positive edge latches data at the host.
	26	GND	Ground
	27	SDIORDY	Secondary I/O Channel Ready – When negated extends the host transfer cycle
			of any host register access when the drive is not ready to respond to a data
			transfer request. High impedance if asserted.
	28	NU	Not used (Pull down to ground through 470 ohm resistor)
	29	SDDACK*	Secondary DMA Acknowledge – Used by the host to acknowledge data has
			been accepted or data is available. Used in response to DMARQ asserted.
	30	GND	Ground
	31	IRQ15	Interrupt Request 15 – Asserted by drive when it has pending interrupt (PIO
			transfer of data to or from the drive to the host).
	32	NC	Not connected

LittleBoard 550 Reference Manual 37