AMROM

AMROM refers to the NES-AMROM and HVC-AMROM boards of the AxROM category.

Overview

• PRG ROM size: 128 KB
• PRG ROM bank size: 32 KB
• PRG RAM: None
• CHR capacity: 8 KB RAM
• CHR bank size: Not bankswitched
• Nametable mirroring: Single-screen, mapper-selectable
• Subject to bus conflicts: Yes

Banks

• CPU $8000-$ffff : 32 KB Switchable PRG ROM bank.

The AMROM board always have 4 PRG ROM banks.

Solder pad config

No solder pad config is needed on the AMROM board.

Chips and pinout

• PRG ROM - 1 MBit (128 KB x 8) (DIP-28) :

                       ---U---
                A15 - |01   28| - +5V
                A12 - |02   27| - A14
                A7  - |03   26| - A13
                A6  - |04   25| - A8 
                A5  - |05   24| - A9
                A4  - |06   23| - A11
                A3  - |07   22| - A16
                A2  - |08   21| - A10
                A1  - |09   20| - /CE (/ROMSEL)
                A0  - |10   19| - D7
                D0  - |11   18| - D6
                D1  - |12   17| - D5
                D2  - |13   16| - D4
                GND - |14   15| - D3
                       -------

This pinout is not compatible with standard 27C010 EPROMs, so to insert them in the board manual rewiring is needed.

• CHR-RAM - 64 kBit (8 KB x 8) (DIP-28) : Standard 6264 pinout.

• 74HC161 (DIP-16)