17
Memory Selection Jumpers
The factory setting for the jumpers should be correct for the memory devices that came with
your board. If you add or modify the type or size of memory, you must change the following
jumpers accordingly. All memory selection jumpers are two-pin jumpers and are installed
vertically.
JP3
- U5 Device Configuration
Must be
ON
if a 32K device is installed in U5. If an 8K device is installed in U5 then:
OFF
configures 8K from 0000 - 1FFF and mirrored at 2000 - 3FFF, 4000 - 5FFF, and
6000 - 7FFF. This position will allow CPU internal Ram and I/O ports to segment the
8K address space.
ON
configures 8K from 2000 - 3FFF hex and mirrored at 6000 - 7FFF. This is the
recommended position for Buffalo Monitor and Small C operation. No segmentation
occurs.
JP4 - JP6
- U6 Device Configuration
JP6 write protects the device in U6 when OFF.
JP4
JP5
JP7
JP6
8K RAM or EEPROM
OFF
OFF
OFF
ON
8K EPROM
OFF
OFF
OFF
OFF
32K EPROM
OFF
ON
ON
OFF
32K RAM or EEPROM
ON
OFF
ON
ON
JP8, JP9, WRITE_EN
- U7 Device Configuration
WRITE_EN write protects the device in U7 when OFF.
JP8
JP9
WRITE_EN
8K EEPROM
OFF
OFF
ON
8K EPROM
OFF
OFF
OFF
32K EPROM
OFF
ON
OFF
32K EEPROM
ON
OFF
ON
