Panasonic JB-3300 Technical Manual page 152

Table 5-1 shows the relationship between MPU addresses and decoder
output.
Table 5-1 Memory Address Decoding
MPU Address
Short Plug] Refresh
513 *DACKO Output Signal
AB19 AB18 AB17 AB16 AB15 AB14
0 x x x x x "A" RAMSEL ..... "HIGH"
*RAMASEL ... "LOW"
SELA ..ceee- "LOW"
SELB ....... "LOW"
Standard 256K bytes
selection
O x x x x x "yr" *RAMASEL ... "HIGH"
Other output signals are
the same as above.
Refresh operation
selection
1 x x x x Short x No selection output
1 x x x x Open my RAMSEL ..... "HIGH"
*RAMASEL ... "LOW"
SELA 2.2.00 "HIGH"
SELB ....... "LOW"
Expansion 256K bytes
selection
0 1 1 1 x x x *VRAMSEL ... "LOW"
Video RAM selection
1 1 1 1 1 x X *ROMSEL .... "LOW"
ROM selection
Xs
Do not care
If - 32