Tekram Technology DC-820B - Manual (Page 24)

EISA Fast SCSI Caching Adapter
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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