MSX Panasonic FS-A1F (modifications)

Idea: substitute ROM “MEI 1987 / DA1024D0365R” with a EEPROM 27C series

To Read the ROM chip, my EPROM Programmer (TL866CS) currently don’t support this model of ROM, so I plugged in with pin 1 of ROM into pin 3 of socket, rise pins 22 and 28, wired pin 28 to vcc (pin 32?? pin 2?? of socket)

How to read ROM “MEI 1987 / DA1024D0365R”

  • Rise ROM pins 22 and 28
  • Plugged this ROM into a Programmer’s socket with pin 1 of ROM into pin 3 of socket
  • wire pin 28 of ROM to VCC (socket empty pin 32)
  • wire pin 22 of ROM to A16 (socket empty pin 2)
  • choose chip type as EEPROM 27C010
  • after read, will have a file with 128KB
    • sha1: 9a62d7a5ccda974261f7c0600476d85e10deb99b
    • sha256: 6A878A86B7B5E7E4EAAE82E1DF175D1EAFB20F813FC7157AB6AFF9506736B420

ROM “DA1024D0365R” Contents

offset begin offset end size function
00000h 07FFFh 32KB Main-ROM
08000h 0BFFFh 16KB Sub-ROM
0C000h 0FFFFh 16KB Disk-ROM
10000h 17FFFh 32KB Kanji driver
18000h 1FFFFh 32KB A1 Cockpit

MSX Panasonic FS-A1F physical view ROM contents

Addresses slot 0 slot 3-1 slot 3-2 slot 3-3
8000-BFFF Kanji driver A1 Cockpit
4000-7FFF Main-ROM Kanji driver Disk ROM A1 Cockpit
0000-3FFF Main-ROM Sub-ROM

MSX Panasonic FS-A1F logic view of ROM contents



  • MSX2 Panasonic FS-A1F wiki tutorials
  • FS-A1FX Rom with FM Music and no Cockpit
  • Output Enable Vs. Chip Select
    • Many memory devices designed to connect to a bus (such as RAM and ROM chips) have both CS (chip select) and OE (output enable) pins, which superficially appear to do the same thing. If CS is not asserted, the outputs are high impedance.

    • The difference lies in the time needed to output the signal. When chip select is deasserted, the chip does not operate internally, and there will be a significant delay between providing an address and receiving the data. (An advantage of course, is that the chip consumes minimal power in this case.)