PM2021A/90, PM2021A/95 Hard Disk/Floppy Controller Settings and Configuration

Data bus:	16-bit, ISA (PM2021A/9x)
Size:	Half-length, full-height card
Hard drive supported:	Up to seven SCSI drives
Floppy drives supported:	Two 360KB, 720KB, 1.2MB, or 1.44MB drives (PM2x2x/95 only)

CONNECTIONS
Function	Location
CM4000 Cache Module Connector	P1
CM4000 Cache Module Connector	P2
DM4000 Disk Array Module Connector	P5
4-pin connector-Drive active LED	P6
DM400 Disk Array Module Connector	P7
34-pin control cable connector-floppy drive	P8
50-pin SCSI connector - internal	P10
50-pin SCSI connector - external	J11

DMA TRANSFER RATE
Speed		Jumper Y12	Jumper Y13	Jumper Y14
	10MB/sec	open	open	open
	8MB/sec	closed	open	open
	6.667MB/sec	open	closed	open
	5.7MB/sec	closed	closed	open
»	5.0MB/sec	open	open	closed
	4.4MB/sec	closed	open	closed
	4.0MB/sec	open	closed	closed
	3.0MB/sec	closed	closed	closed

SCSI ADDRESS
SCSI I.D.		Jumper Y18	Jumper Y25	Jumper Y26
	0	open	open	open
	1	open	closed	open
	2	closed	open	open
	3	closed	closed	open
	4	open	open	closed
	5	open	closed	closed
	6	closed	open	closed
»	7	closed	closed	closed

INTERRUPT REQUEST
IRQ		Y29	Y30
	Disabled	open	open
	IRQ12	open	closed
»	IRQ15	closed	open
	IRQ14	closed	closed

DMA CHANNEL
DRQ		Y31	Y32
	DRQ0	open	open
	DRQ7	open	closed
	DRQ6	closed	open
»	DRQ5	closed	closed

I/O PORT ADDRESS
Address		Y33	Y35
	230h	open	open
»	170h	open	closed
	330h	closed	open
	1F0h	closed	closed

BIOS ADDRESS
Address		Y36	Y37
	Disabled	open	open
	DC00h	open	closed
	D800h	closed	open
»	C800h	closed	closed

USER CONFIGURABLE SETTINGS
Function		Location	Setting
»	DMA duty cycle is fast	Y15	open
	DMA duty cycle is slow	Y15	closed
»	SCSI termination enabled	Y16	closed
	SCSI termination disabled	Y16	open
»	Address LInes SA17-19 and LA17-19 driven	Y19	closed
	Only Address LInes LA17-19 driven	Y19	open
»	Floppy drive enabled	Y20	closed
	Floppy drive disabled	Y20	open
»	Bus Mastering enabled	Y24	closed
	Bus Mastering disabled	Y24	open
»	BIOS ROM size is 8K	Y38	open
	BIOS ROM size is 16K	Y38	closed
»	External SCSI cable detection disabled	Y39	open
	External SCSI cable detection enabled*	Y39	closed
»	Controller supplies TERMPWR to SCSI interface 26	Y50	closed
	TERMPWR not supplied to SCSI Interface 26	Y50	open

STATUS LED'S
LED	Definition
LED 1	Busy
LED 2	Computer Bus Transfer to Adapter
LED 3	Computer Bus Transfer from Adapter
LED 4	Cache Hit
LED 5	Disk Read-Ahead Active
LED 6	Disk Read
LED 7	Disk Write
LED 8	Adapter Reset
LED 9	Interrupt Pending to Computer
LED 10	DRQ Asserted to Computer

MISCELLANEOUS TECHNICAL NOTES

Detection of an external SCSI cable limits the maximum SCSI bus transfer rate to 5MB/sec. The function of Jumper Y34 is unknown.