Panasoft SW-M001
This page was last modified 19:41, 26 May 2023 by Mars2000you. Based on work by Gdx and Rderooy.



The SW-M001 is a cartridge from Panasoft that contains 8kB SRAM for saving game data. Its product name is PAC (Pana Amusement Cartridge).

The 8kB is arbitrarily divided into 8 pages of 1024 Bytes each. A game may use one or more pages to save its data.

Some games allow you to select which pages to use, others are hardcoded to use specific pages. It is up to the user to ensure he does not overwrite old save states from the game, or save states of other games. Method access to SRAM is described here.

There is an option to backup save states to disk.


Panasoft PAC cartridge box scan
Panasoft PAC cartridge scan
Panasoft PAC cartridge
Panasoft PAC PCB
Panasoft PAC PCB underside

Backup/Restore save states

Unlike the Panasoft FM-PAC, the PAC does not come with any software to backup or restore the save states.

There are however a few ways. One way is to have a Panasoft FM-PAC in addition to a PAC inserted, you can then run the FM-PAC software (by entering CALL FMPAC from BASIC), and copy the contents of both the FM-PAC and the PAC. Alternatively there are these tools to make or restore backups.


The PAC (and likewise the Panasoft FM-PAC) has a non-rechargeable battery, without it the SRAM will not keep the contents when the system is switched off. This coin cell battery can be replaced, you need to open the cartridge and replace the battery by soldering a new one (type: CR2025 or BR2025 Lithium 3V). Confirmation is needed about battery pins type. Be careful not to overheat the battery when soldering it, and put on safety glasses because of the risk of explosion with heat.

Typically a PAC compatible game will have one of these logo's on the box. They may also indicate which save data pages they need.

PAC Logo
PAC Logo translated
PAC Logo
PAC Logo translated
Additional PAC Logo to indicate the game needs block 8 only
Additional PAC Logo to indicate the game needs block 1-4 only

Software using the PAC to save data

Rom Cartridges

  • AshGuine - Flame of Vengeance (Panasoft)
  • AshGuine - Stronghold Of The Void (Panasoft)
  • Crimson (Scap Trust)
  • Cosmic Soldier 2 - Psychic War (KGD)
  • Famicle Parodic (Bit^2)
  • Fire Ball (Humming Bird Soft)
  • Hydlide 3 The Space Memories [MSX1] (T&E Soft)
  • Hydlide 3 The Space Memories [MSX2] (T&E Soft)
  • Inindo - The overthrow of Nobunaga (Koei)
  • J.B. Harold’s case file #1 - Murder Club (Micro Cabin)
  • L'Empereur (Koei)
  • Maison Ikkoku - Final Chapter (Micro Cabin)
  • Nobunaga's Ambition - Nationwide Edition (Koei)
  • Penguin-kun Wars 2 (ASCII)
  • Predator (Pack-in-Video)
  • Quinpl (Bit^2)
  • Royal Blood (Koei)
  • Super Grand Strategy (Micro Cabin)
  • The Blue Wolf and The White Stag - Yuan Dynasty Secret History (Koei)
  • The Return of Ishtar (Namcot)
  • Urusei Yatsura - Love Survival Anniversary (Micro Cabin)
  • Wizardry - Proving Grounds of the Mad Overlord (Sir-Tech, ASCII)
  • Yaksa (Wolfteam)
  • Yosuke Ide's Master Mahjong (Pack-in-Video)

Floppy Disks

  • Ashgine - The Fortress of nothingness (Ashguine II)
  • Daisenryaku II - Campaign Version (Micro Cabin)
  • Dragon Slayer - The Legend of Heroes (Works on FM-PAC only because doesn't perform SRAM detection)
  • Fire Hawk - Thexder The Second Contact
  • Fray - In Magical Adventure (Micro Cabin)
  • Greatest Driver (T&E Soft)
  • Hiroku Kubikiri Yakata (Bit^2)
  • J.B. Harold’s case file #1 - Murder Club (Micro Cabin)
  • J.B. Harold’s case file #2 - Manhattan Requiem (Riverhill Soft Inc.)
  • J.B. Harold’s case file #3 - Kiss of Murderous Intent (Riverhill Soft Inc.)
  • Kimagure Orange Road
  • Magical Labyrinth Remix (Gigamix)
  • Magnar (Parallax)
  • Moon Light Saga - Horus Chapter
  • Psy-O-Blade
  • Psycho World
  • Quinpl (Bit^2)
  • Ys II

Devices that have PAC compatible SRAM

Note: Contrary to what the name seems to indicate, the MIDI-PAC does not have PAC SRAM.

External links