Memory bank | Associated I/O ports | ||
---|---|---|---|
Expanded RAM | E2h: Bit 4, 0 Read/Write enabled E3h: Bank selection | ||
EROM (4th ROM) | 31h: Bit 2 (RMODE = 0) 31h: Bit 1 (MMODE = 0) 71h: Bit 0 (IEROM = 0) 32h: Bit [1:0] (EROMSL) Bank selection | ||
N88-BASIC ROM | 31h: Bit 2 (RMODE = 0) 31h: Bit 1 (MMODE = 0) | ||
N-BASIC ROM | 31h: Bit 2 (RMODE = 1) 31h: Bit 1 (MMODE = 0) | ||
Main RAM | 31h: Bit 1 (MMODE = 1) | ||
GVRAM | 5Ch, 5Dh, 5Eh: in independent access mode 35h: Bit 7 (GAM = 1) In extended access mode | ||
High speed TVRAM | 32h: Bit 4 (TMODE = 0) |
When ROM is selected from 0000h to 7FFFh, writing into this range of addresses is done to main RAM.