Check the listing for details. Alesis S4 Quadrasynth OS v1.07 EPROM Firmware Upgrade KIT / ROM Update Chip. Condition: New. Listed at 27.95 USD. Alesis S4 Quadrasynth OS version 1.07 EPROM Firmware Upgrade KIT / ROM Update Chip This upgrade version 1.07 is the latest and final firmware update issued by Alesis for the S4 Quadrasynth unit. Included will be 1 new EPROM chip, recently manufactured to ensure data integrity well past our natural lifetime. Please note that the S4 itself is not for sale, only the EPROM upgrade chip will be supplied. Unlike some others, No used or refurbished as “new” components will be supplied here. Protect your investment! This version 1.07 upgrade is serves as a supplemental release, intended to iron out any remaining kinks affecting general stability, bugs and improve performance within the firmware code. This upgrade ROM is also compatible with the S5. This upgrade ROM is NOT compatible with the S4 Plus and S5 Plus. Be sure to take note of the marked orientation notch on the side of the EPROM to ensure correct installation. EPROMS inserted backwards will be destroyed. Incorrect insertion of ICs is also likely to cause damage to the board. All EPROM upgrades have been prepared in an ESD-safe production environment and will be packaged in equally ESD-safe materials. Purchase with confidence!