Xycom XVME-678 Manual page 51

XVME-678/688 Manual
July 1994
3.3.1.15 Internal COM A and COM B
These selections individually set the port address that will be programmed by the BIOS for each port.
There are three options:
• Off
• Default for COM A
COM1 (3F8h)
COM2 (2F8h)
• Default for COM B
NOTE
It is recommended that automatic configuration be used to select the COM
and LPT ports. Automatic configuration selects the first logical port address
that does not conflict with any other communication ports in your system.
If the addresses are selected manually, conflicts with other devices in the
system may occur.
3.3.1.16 Internal LPf
(off/LPT1 at 378h/278h/3BCh)
This item selects the port address to be programmed by the BIOS for the internal LPT port. There are
four options:
• Off
• LPT1 at 378h
• LPT1 at 278h
• LPT1 at 3BCh
3.3.1.17 System Memory Cache
(Off/Qn/N/A)
The system memory cache option-which refers to the XVME-678' s 1 Kbyte internal cache on the
486SLC/e-can be enabled or disabled by changing the field to ON or OFF. If the cache is disabled
(OFF), the XVME-678 takes longer to perform memory accesses, degrading system performance. The
XVME-688 does not support this option, so NI A is the default.
3.3.1.18 AT-bus Speed
(8.33/10
MHz)
The AT -bus speed is software selectable on power-up. Bus speed can be 8 or 10 MHz.
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