PL1 STEbus connector

PL2. Disk DMA control connector

PL3 Standard 34-way floppy disk connector

Semiconductors

IC1		LS245		STEbus data buffers
IC2,3,5		LS244		STEbus address buffers
IC4		PAL6R4		J138_U4
IC6		uPD765		FDC
IC7		74LS30		
IC8,11		7405		
IC9		FE2100    	LSI glue logic
IC10		74LS04		
IC12		74LS07		
TR1,2		2N2369A		NPN

Resistors

R1			4k7	
R2,3,5,6		150R
R4			200k
R7,8			2k2

Capacitors

C1,2,7,12	22µ 16V tantalum
C3-7,8-12,14,16	100n
C13		47p

Miscellaneous

XL1		8 MHz crystal

SPDC PC-Compatible Floppy Disk Controller

The SPDC is a floppy disk controller for STEbus PC-compatible systems. Controlling up to four drives, the SPDC can be used with 5.25" or 3.5" drives (40 or 80 track double-sided double density). An on-board custom IC interfaces with the industry standard Intel 8272 or NEC µ765 floppy disk controller chip, to provide complete PC-compatibility, when used with other STEbus PC boards. With no links on-board for set up, the SPDC is simple to install and use.

Interface:

STEbus slave interface.

Power consumption:

Typ 0.5A @ 5V

Features:

• Supports DMA and interrupts
• Up to four 3.5" or .25" floppy drives

Ordering information:

SPDC Floppy Disk Controller