| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | This is the README file for the Optics Storage 8000 AT CDROM device driver. |
| 2 | |
| 3 | This is the driver for the so-called 'DOLPHIN' drive, with the 34-pin |
| 4 | Sony-compatible interface. For the IDE-compatible Optics Storage 8001 |
| 5 | drive, you will want the ATAPI CDROM driver. The driver also seems to |
| 6 | work with the Lasermate CR328A. If you have a drive that works with |
| 7 | this driver, and that doesn't report itself as DOLPHIN, please drop me |
| 8 | a mail. |
| 9 | |
| 10 | The support for multisession CDs is in ALPHA stage. If you use it, |
| 11 | please mail me your experiences. Multisession support can be disabled |
| 12 | at compile time. |
| 13 | |
| 14 | You can find some older versions of the driver at |
| 15 | dutette.et.tudelft.nl:/pub/linux/ |
| 16 | and at Eberhard's mirror |
| 17 | ftp.gwdg.de:/pub/linux/cdrom/drivers/optics/ |
| 18 | |
| 19 | Before you can use the driver, you have to create the device file once: |
| 20 | # mknod /dev/optcd0 b 17 0 |
| 21 | |
| 22 | To specify the base address if the driver is "compiled-in" to your kernel, |
| 23 | you can use the kernel command line item (LILO option) |
| 24 | optcd=0x340 |
| 25 | with the right address. |
| 26 | |
| 27 | If you have compiled optcd as a module, you can load it with |
| 28 | # insmod /usr/src/linux/modules/optcd.o |
| 29 | or |
| 30 | # insmod /usr/src/linux/modules/optcd.o optcd=0x340 |
| 31 | with the matching address value of your interface card. |
| 32 | |
| 33 | The driver employs a number of buffers to do read-ahead and block size |
| 34 | conversion. The number of buffers is configurable in optcd.h, and has |
| 35 | influence on the driver performance. For my machine (a P75), 6 buffers |
| 36 | seems optimal, as can be seen from this table: |
| 37 | |
| 38 | #bufs kb/s %cpu |
| 39 | 1 97 0.1 |
| 40 | 2 191 0.3 |
| 41 | 3 188 0.2 |
| 42 | 4 246 0.3 |
| 43 | 5 189 19 |
| 44 | 6 280 0.4 |
| 45 | 7 281 7.0 |
| 46 | 8 246 2.8 |
| 47 | 16 281 3.4 |
| 48 | |
| 49 | If you get a throughput significantly below 300 kb/s, try tweaking |
| 50 | N_BUFS, and don't forget to mail me your results! |
| 51 | |
| 52 | I'd appreciate success/failure reports. If you find a bug, try |
| 53 | recompiling the driver with some strategically chosen debug options |
| 54 | (these can be found in optcd.h) and include the messages generated in |
| 55 | your bug report. Good luck. |
| 56 | |
| 57 | Leo Spiekman (spiekman@dutette.et.tudelft.nl) |