Cacheable device: Yes/No. This option is only valid for fixed disk, remov- able cartridge, re-writable optical disk (MO) and Floptical. The removable media device with Yes option must insert the media before the system boot- up for caching algorithm to work properly. When the No option is chosen, both the data transfer requests and commands are passed directly to the drive itself.
Parity Checking: Yes/No. This option defaults to enabled, i.e., Yes. If set as No, the DC-820B won't perform the parity checking on the SCSI bus. For some devices that do not implement the parity function, you have to disable this option.
Synchronous Negotiation: AT/PA/NO. AT is for Active Synchronous nego- tiation, in this mode DC-820B will initiate SCSI synchronous negotiation when the system boots up. If the PA, Passive Synchronous Negotiation, mode is chosen, another SCSI device instead of DC-820B must initiate the negotia- tion. NO (default), Asynchronous Negotiation mode, is for the transfer to be done asynchronously, which is normally at a lower rate and not related to the timing constraints of SCSI devices.
Disconnect/Reconnect: Yes/No. Yes is the default option and allows the SCSI device to be off-line by freeing the SCSI bus when performing multi- tasking operation. In this way, the DC-820B can simultaneously process multiple operations on the SCSI bus and thus improve the SCSI bus’ effi- ciency in the multiple device environment.
Max DOS disk capacity: 1G/1.5G/2G/3G/4.5G. 1G is the default option and compatible with AHA 1540/1542 series, that means you can directly port the drive with AHA 1540/1542 series format to the DC-820B. For operating systems other than DOS and NetWare, you must choose the 1G option. Also, to activate options other than 1G, i.e., 1.5G/2G/3G/4.5G,
you have to enable the DOS 5 Support enable/disable in the Adapter
Firmware Options first. The following is the parameter translation informa- tion corresponding to each option (512B/sector):
1G | = 64 heads and 32 sectors, maximum 1GB |
1.5G | = | 64 heads and 48 sectors, maximum 1.5GB |
2G | = 128 heads and 32 sectors, maximum 2GB |
3G | = 128 heads and 48 sectors, maximum 3GB |
4.5G | = | 192 heads and 48 sectors, maximum 4.5GB |
