MattCarp
Experienced Member
I decided to move my MicroPDP-11/73 SCSI card from the Emulex UC07 to the California Micro Devices CQD-440/TM.
I just did that because I wanted the flexibility of a single SCSI adapter that could cover both tape and disk devices, and, the CQD 440's improved speed.
Now that I've done the switch, I have some observations.
Speed. Honestly, I'm just tinkering around, and still pretty new to the PDP-11, so I don't have any benchmarks. That said, the disk I/O feels a little snappier / quicker. I've tested booting off of both a SCSI2SD card and a Seagate ST15230N hard disk. According to the data sheets, the UC07/UC08 support up to 2MB/sec, while the CQD 440 can go up to 10 MB/sec. My Seagate hard disk can deliver a peak data transfer of >5MB/sec. Older SCSI2SD devices do 2.6 MB/sec (read), the latest SCSI2SD device can do up to 10MB/sec. So, it seems possible to use the speed.
Firmware. The built in configuration firmware of the Emulex is definitely more polished and user friendly. The Emulex Firmware Resident Diagnostics (as they call it) has a nice menu structure. One menu item is to display available devices. When you select this, it interrogates the SCSI bus and lists each device along with the number of blocks on that device. The CQD, on the other hand, only seems to display devices after I go through a configuration screen. Interestingly, the CQD doesn't list the size of the device, but, it does get a name from the device for each SCSI ID ("ST15230" or "SCSI2SD" appeared for me in a device list).
The formatting of the text in the display from the CQD wasn't as nice, and, the configuration menus were a couple levels deep.
Documentation. The Emulex manual also seemed to be more clearly laid out, and, more complete, better written. Both the UC07 and the CQD can be deployed in the PDP-11 or the MicroVAX. The UC07 manual does a better job of making configuration clear for each specific target. The CQD manual almost mixes the two. It's not terrible, but I had to look and read to make sure I was following the instructions properly for my PDP. It seems like this card was more intended for the MicroVAX crowd.
I don't think you could go wrong with either card. If I cared to give up speed, I might suggest the UC08 would be a great card, for its disk and tape support, and, better firmware configuration.
One hiccup when I moved my disk from the UC07 to the CQD-440. I couldn't get the physical disk to boot. I wasn't sure what was happening. Since I didn't want to reformat and reinstall software to my disk, I just swapped controllers and hoped for the best. Well, it didn't boot. I restarted the machine, then power cycled the machine, and still had problems. Next, I saw this comment in the CQD manual:
"If you try to skip the formatting process and directly use the drive, you must use this option to eliminate "unrecoverable bad RCT block."" Since I didn't format the disk, I ran this command. I think it still didn't spring to life, but shortly thereafter I think it did.
One thing I'd be curious about is device compatibility. the fainresearch web site says that CQD controllers "have more compatibility issues" than Emulex controllers, but it wasn't specific.
-Matt
I just did that because I wanted the flexibility of a single SCSI adapter that could cover both tape and disk devices, and, the CQD 440's improved speed.
Now that I've done the switch, I have some observations.
Speed. Honestly, I'm just tinkering around, and still pretty new to the PDP-11, so I don't have any benchmarks. That said, the disk I/O feels a little snappier / quicker. I've tested booting off of both a SCSI2SD card and a Seagate ST15230N hard disk. According to the data sheets, the UC07/UC08 support up to 2MB/sec, while the CQD 440 can go up to 10 MB/sec. My Seagate hard disk can deliver a peak data transfer of >5MB/sec. Older SCSI2SD devices do 2.6 MB/sec (read), the latest SCSI2SD device can do up to 10MB/sec. So, it seems possible to use the speed.
Firmware. The built in configuration firmware of the Emulex is definitely more polished and user friendly. The Emulex Firmware Resident Diagnostics (as they call it) has a nice menu structure. One menu item is to display available devices. When you select this, it interrogates the SCSI bus and lists each device along with the number of blocks on that device. The CQD, on the other hand, only seems to display devices after I go through a configuration screen. Interestingly, the CQD doesn't list the size of the device, but, it does get a name from the device for each SCSI ID ("ST15230" or "SCSI2SD" appeared for me in a device list).
The formatting of the text in the display from the CQD wasn't as nice, and, the configuration menus were a couple levels deep.
Documentation. The Emulex manual also seemed to be more clearly laid out, and, more complete, better written. Both the UC07 and the CQD can be deployed in the PDP-11 or the MicroVAX. The UC07 manual does a better job of making configuration clear for each specific target. The CQD manual almost mixes the two. It's not terrible, but I had to look and read to make sure I was following the instructions properly for my PDP. It seems like this card was more intended for the MicroVAX crowd.
I don't think you could go wrong with either card. If I cared to give up speed, I might suggest the UC08 would be a great card, for its disk and tape support, and, better firmware configuration.
One hiccup when I moved my disk from the UC07 to the CQD-440. I couldn't get the physical disk to boot. I wasn't sure what was happening. Since I didn't want to reformat and reinstall software to my disk, I just swapped controllers and hoped for the best. Well, it didn't boot. I restarted the machine, then power cycled the machine, and still had problems. Next, I saw this comment in the CQD manual:
"If you try to skip the formatting process and directly use the drive, you must use this option to eliminate "unrecoverable bad RCT block."" Since I didn't format the disk, I ran this command. I think it still didn't spring to life, but shortly thereafter I think it did.
One thing I'd be curious about is device compatibility. the fainresearch web site says that CQD controllers "have more compatibility issues" than Emulex controllers, but it wasn't specific.
-Matt
