|README file for the Linux DTC3180/3280 scsi driver.
|by Ray Van Tassle (firstname.lastname@example.org) March 1996
|Based on the generic & core NCR5380 code by Drew Eckhard
|SCSI device driver for the DTC 3180/3280.
|Data Technology Corp---a division of Qume.
|The 3280 has a standard floppy interface.
|The 3180 does not. Otherwise, they are identical.
|The DTC3x80 does not support DMA but it does have Pseudo-DMA which is
|supported by the driver.
|Its DTC406 scsi chip is supposedly compatible with the NCR 53C400.
|It is memory mapped, uses an IRQ, but no dma or io-port. There is
|internal DMA, between SCSI bus and an on-chip 128-byte buffer. Double
|buffering is done automagically by the chip. Data is transferred
|between the on-chip buffer and CPU/RAM via memory moves.
|The driver detects the possible memory addresses (jumper selectable):
| CC00, DC00, C800, and D800
|The possible IRQ's (jumper selectable) are:
| IRQ 10, 11, 12, 15
|Parity is supported by the chip, but not by this driver.
|Information can be obtained from /proc/scsi/dtc3c80/N.
|Note on interrupts:
|The documentation says that it can be set to interrupt whenever the
|on-chip buffer needs CPU attention. I couldn't get this to work. So
|the driver polls for data-ready in the pseudo-DMA transfer routine.
|The interrupt support routines in the NCR3280.c core modules handle
|scsi disconnect/reconnect, and this (mostly) works. However..... I
|have tested it with 4 totally different hard drives (both SCSI-1 and
|SCSI-2), and one CDROM drive. Interrupts works great for all but one
|specific hard drive. For this one, the driver will eventually hang in
|the transfer state. I have tested with: "dd bs=4k count=2k
|of=/dev/null if=/dev/sdb". It reads ok for a while, then hangs.
|After beating my head against this for a couple of weeks, getting
|nowhere, I give up. So.....This driver does NOT use interrupts, even
|if you have the card jumpered to an IRQ. Probably nobody will ever