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Linus Torvalds1da177e2005-04-16 15:20:36 -07001This is the README file for the Optics Storage 8000 AT CDROM device driver.
2
3This is the driver for the so-called 'DOLPHIN' drive, with the 34-pin
4Sony-compatible interface. For the IDE-compatible Optics Storage 8001
5drive, you will want the ATAPI CDROM driver. The driver also seems to
6work with the Lasermate CR328A. If you have a drive that works with
7this driver, and that doesn't report itself as DOLPHIN, please drop me
8a mail.
9
10The support for multisession CDs is in ALPHA stage. If you use it,
11please mail me your experiences. Multisession support can be disabled
12at compile time.
13
14You can find some older versions of the driver at
15 dutette.et.tudelft.nl:/pub/linux/
16and at Eberhard's mirror
17 ftp.gwdg.de:/pub/linux/cdrom/drivers/optics/
18
19Before you can use the driver, you have to create the device file once:
20 # mknod /dev/optcd0 b 17 0
21
22To specify the base address if the driver is "compiled-in" to your kernel,
23you can use the kernel command line item (LILO option)
24 optcd=0x340
25with the right address.
26
27If you have compiled optcd as a module, you can load it with
28 # insmod /usr/src/linux/modules/optcd.o
29or
30 # insmod /usr/src/linux/modules/optcd.o optcd=0x340
31with the matching address value of your interface card.
32
33The driver employs a number of buffers to do read-ahead and block size
34conversion. The number of buffers is configurable in optcd.h, and has
35influence on the driver performance. For my machine (a P75), 6 buffers
36seems optimal, as can be seen from this table:
37
38#bufs kb/s %cpu
391 97 0.1
402 191 0.3
413 188 0.2
424 246 0.3
435 189 19
446 280 0.4
457 281 7.0
468 246 2.8
4716 281 3.4
48
49If you get a throughput significantly below 300 kb/s, try tweaking
50N_BUFS, and don't forget to mail me your results!
51
52I'd appreciate success/failure reports. If you find a bug, try
53recompiling the driver with some strategically chosen debug options
54(these can be found in optcd.h) and include the messages generated in
55your bug report. Good luck.
56
57Leo Spiekman (spiekman@dutette.et.tudelft.nl)