|
SCSI BIOS
|
|
Three different SCSI BIOS addresses may be selected, or the ROM may be disabled, as shown below. In systems with multiple DPT SCSI adapters, only one adapter should have its SCSI BIOS enabled. An alternate ROM address may be chosen to avoid conflict with BIOSs for other peripheral cards.
* = Factory Default
| Y37 | Y36 | ROM Address |
|---|
| ON | ON | C800h* |
| OFF | ON | D800h |
| ON | OFF | DC00h |
| OFF | OFF | Disabled |
|
|
|
| |
|
I/O Address, DRQ and IRQ
|
|
Four I/O address settings and DMA channels, and three interrupt levels may be selected for the PM2021 as shown below.
| Y35 | Y33 | I/O Address |
|---|
| ON | OFF | 170h* |
| ON | ON | 1F0h |
| OFF | OFF | 230h |
| OFF | ON | 330h |
|
|
| Y31 | Y32 | DMA Channel |
|---|
| ON | ON | DRQ 5* |
| ON | OFF | DRQ 6 |
| OFF | ON | DRQ 7 |
| OFF | OFF | DRQ 0 |
|
|
| Y29 | Y30 | Interrupt Level |
|---|
| ON | OFF | IRQ 15* |
| ON | ON | IRQ 14 |
| OFF | ON | IRQ 12 |
| OFF | OFF | Disabled |
|
| |
|
SCSI ID
|
|
Normally, the SCSI ID of the PM2021 should not be changed from the default setting of ID 7.
| Y25 | Y18 | Y26 | SCSI ID |
|---|
| ON | ON | ON | 7* |
| OFF | ON | ON | 6 |
| ON | OFF | ON | 5 |
| OFF | OFF | ON | 4 |
| ON | ON | OFF | 3 |
| OFF | ON | OFF | 2 |
| ON | OFF | OFF | 1 |
| OFF | OFF | OFF | 0 |
|
| |
|
SCSI Termination
|
|
The PM2021 adapter includes SCSI II active termination which is enabled or disabled as shown below.
| Y16 | Termination |
|---|
| ON | Enabled* |
| OFF | Disabled |
|
| |
|
SCSI Termination Power
|
|
SmartCache III adapters always provide power for their own SCSI termination option. In addition, the adapters can provide termination power on the TERMPWR line for terminators on other devices.
| Y50 | TERMPWR |
|---|
| ON | Enabled* |
| OFF | Disabled |
|
| |
|
External Cable Detect
|
|
The PM2021 adapter can sense when an external cable is attached and limit the maximum SCSI bus transfer speed to 5MB/s.
| Y39 | Cable Detection |
|---|
| ON | Enabled |
| OFF | Disabled* |
|
| |
|
DMA Speed Options
|
|
The ISA DMA transfer rate as well as duty cycle may be selected as shown below. DMA duty cycle is selected by Y15 to control the bus-on time. Bus-on time is defined as the time the PM2021 holds the bus before relinquishing it for refresh.(Bus-off time, the time the PM2021 waits before reasserting DRQ to regain the bus after a preempt, is always set to 1.6us.)
|
|
The bus on-time may require modification when using floppy-based tape solutions. The default DMA setting should work fine for most systems.
| Y12 | Y13 | Y14 | DMA Transfer Rate (MB/s) |
|---|
| OFF | OFF | OFF | 10 |
| ON | OFF | OFF | 8 |
| OFF | ON | OFF | 6.667 |
| ON | ON | OFF | 5.7 |
| OFF | OFF | ON | 5.0* |
| ON | OFF | ON | 4.4 |
| OFF | ON | ON | 4.0 |
| ON | ON | ON | 3.0 |
|
|
| Y15 | Mode | Bus-On Time |
|---|
| OFF | Fastest | 12.8us* |
| ON | Slowest | 6.4us |
|
| |
|
LA/SA17-19 Lines
|
|
On a few ISA systems, address lines LA17-19 are connected to SA17-19. The PM2021 by default drives both LA17-19 and SA17-19. If you are installing a PM2021 in a system that does connect LA17-19 and SA17-19, then remove Jumper Y19 so that only LA17-19 will be driven by the PM2021.
| Y19 | Address Lines Driven |
|---|
| ON | SA17-19 and LA17-19* |
| OFF | Only LA17-19 |
|
| |
|
ISA Bus Mastering
|
|
Most ISA systems support bus mastering. If the user's system does not support ISA bus mastering transfers then Y24 may be removed to use PIO data transfers instead.
| Y24 | Bus Mastering |
|---|
| ON | Enabled* |
| OFF | Disabled |
|
| |
|
Floppy Controller Address
|
|
Two different floppy controller address settings may be selected, allowing the system to be configured with two floppy controllers.
| Y34 | Floppy Address |
|---|
| OFF | 3F0h (Primary)* |
| ON | 370h (Secondary) |
|
| |
|
Floppy Controller
|
|
The PM2021/95 floppy controller can be enabled or disabled as shown below to avoid conflict with other floppy controllers.
| Y20 | Floppy Controller |
|---|
| ON | Enabled* |
| OFF | Disabled |
|
|