Panasonic mapper
This page was last modified 12:02, 9 September 2017 by Gdx. Based on work by Mars2000you and NYYRIKKI.

Contents

Description

Panasonic mapper is the mapper used in newest MSX2+ (FS-A1WX/FS-A1WSX) and MSX Turbo R (FS-A1ST/FS-A1GT).

The Panasonic Mapper has a page switching system located in Slot 3-3 that allows you to select any content from internal memory (RAM, ROM or SRAM) independently of slot selection. The controller also has registers that give the selected page number of the banks.

Caution: This document is not valid for the FS-A1FX.

Addresses to access Panasonic mapper registers

To access the least significant 8 bits of each registers of page switching

  • 6000h~63FFh (W): Switching the page on bank 0000h~1FFFh
  • 6400h~67FFh (W): Switching the page on bank 2000h~3FFFh
  • 6800h~6BFFh (W): Switching the page on bank 4000h~5FFFh
  • 6C00h~6FFFh (W): Switching the page on bank 6000h~7FFFh
  • 7000h~73FFh (W): Switching the page on bank 8000h~9FFFh
  • 7800h~7BFFh (W): Switching the page on bank A000h~BFFFh
  • 7400h~77FFh (W): Switching the page on bank C000h~DFFFh (mirror from bank 4000h~5FFFh on FS-A1WX/FS-A1WSX)
  • 7C00h~7FEFh (W): Switching the page on bank E000h~FFFFh (mirror from bank 6000h~7FFFh on FS-A1WX/FS-A1WSX)

To access registers of page number reading

  • 7FF0h (R): Reading current page number on bank 0000h~1FFFh
  • 7FF1h (R): Reading current page number on bank 2000h~3FFFh
  • 7FF2h (R): Reading current page number on bank 4000h~5FFFh
  • 7FF3h (R): Reading current page number on bank 6000h~7FFFh
  • 7FF4h (R): Reading current page number on bank 8000h~9FFFh
  • 7FF5h (R): Reading current page number on bank A000h~BFFFh
  • 7FF6h (R): Reading current page number on bank C000h~DFFFh
  • 7FF7h (R): Reading current page number on bank E000h~FFFFh

Note: These registers are valid only if the bit 2 of 7FF9h is set.

To access the most significant bit of all registers of page switching

  • 7FF8h (R/W): Registers that contains all 9th bits of page switching
   bit0 for most significant bit of the page on bank 0000h~1FFFh
   bit1 for most significant bit of the page on bank 2000h~3FFFh
   bit2 for most significant bit of the page on bank 4000h~5FFFh
   bit3 for most significant bit of the page on bank 6000h~7FFFh
   bit4 for most significant bit of the page on bank 8000h~9FFFh
   bit5 for most significant bit of the page on bank A000h~BFFFh
   bit6 for most significant bit of the page on bank C000h~DFFFh
   bit7 for most significant bit of the page on bank E000h~FFFFh

Note: This register does not exist on the FS-A1WX/FS-A1WSX.

To access configuration register

  • 7FF9h (R/W): Register to enable/disable addresses
   bit2 to 1 to enable the reading of the page number via the 7FF0h~7FF7h
   bit3 to 1 make the configuration register readable at 7FF9h
   bit4 to 1 to enable registers of the 9th page switching bits at 7FF8h (unused on the FS-A1WX/WSX)


Pages content

The follwing is not precise because we do not analyze it well.

  • From page 0, there seems to have firmware.
  • From page 028h, there is the Main-Rom.
  • From page 080h, there is S-RAM. WX/WSX have SRAM on 80h~81h. Pages 82-83h, 84-85h and 86-87h are mirrors. ST have SRAM on 80h~81h without mirror. GT have SRAM on 80h~83h, 84h~87h are not mirror.
  • From page 100h, there is the data of the ROM Disk. (FS-A1GT)
  • From page 180h, there is the Main-RAM in front.


This wiki is based on the Tsujikawa’s document about the internal mapper of Panasonic MSX2+ and Turbo R from the achive “mctr_anl.lzh” and these pages here and there. (in Japanese)