Vector 4 - Page 172

VECTOR 4
TECHNICAL INFORMATION
SECTION III - ADDRESSING BLOCKS OF MEMORY FOR GRAPHICS
summary: This section desceribes jumper connections used to address
memory to specific sections of the RAM. This special addressing
may be required for some users' programs requiring specific memory
addressing to handle graphies capabilities.
2.l Configurations
This section describes jumper connections for two system configurations:
standard Vector 4 with 128Kbytes of RAM, and Vector 4 with extended RAM
(256Kbytes). See Section II to determine jumper position for determining type
of memory used.
Briefly, the standard 128Kbyte memory permits addressing one of four blocks
of memory (from addresses @#@g@g@H through 1FFFEH). The 256Kbyte version
permits addressing one of an additional four blocks of memory, as well
(addresses 2@@#dH through 3FFFEH). Jumper options for the first four blocks
of the 256Kbyte version are identical to options for the 128Kbyte version.
Note that it is necessary to perform jumper connections described in
Section II, enabling 256Kbyte RAM, before it will be possible to use 256Kbyte
memory for graphies. You may want to check Jumper Area B before
connecting any jumpers or performing any other work designed to enable
256Kbyte RAM.
To connect jumpers for enabling memory addressing, locate Jumper Area C on
the Vector 4 SBC, Refer to Exhibit VI-12 (Vector 4 SBC Component Drawing)
for location information.
To enable addressing of each Bloek, locate pins Al16, A15, and Al4 in Jumper
Area C. Connect or cut jumper wires as indicated:
C indicates closing the connection (position §)
O indicates opening the connection (position 1)
Cut or join jumper pads as indicated in Exhibit IV-1l, next page.
09-01-32
7200-0001
IV
3-1