Upgrading the Akai S1000 OS to V4.4

The Akai S1000 has arrived, first function checks were successful and revealed a nice surprise: My S1000 comes equipped with 10 MB of RAM instead of the 2 MB that were listed in the eBay auction. But now it’s time to employ some upgrades to the machine. Originally my plan was to start with the barely readable display, but the eBay seller from whom I ordered the replacement display still has not shipped, so I will start with the OS upgrade.

My S1000 came equipped with OS 2.2. While it works perfectly fine, OS 4.4 is out there and introduces compatibility with Akai S3000 sample files. V4.4 EPROMs can be bought on eBay for reasonable prices (around 15€ at the time of writing), but I own an EPROM burner, so I will create my own V4.4 EPROMS.

With a bit of googling the 4.4 EPROM files can be found, for example, at the Synthesizer ROM Archive (scroll down through the huge list of firmware to the “Akai S1000 (v4.4) EPROM Firmware (FIXED).zip” entry).

The original 2.2 EPROMs are two AMD AM27C512-150DC which can be bought for around 3€ on eBay. The “150” part in the name is the access time (150 ns) - I guess faster EPROMs may work as well, but I went the safe way and got this exact model.

After burning the two files (S1000 44 LSB.bin and S1000 44 MSB.bin) to the EPROMs I printed some nice labels (label printer FTW!) to cover the little window on them in order to prevent UV light from erasing the data. Removing the old EPROMs is best done with an IC removal tool, or, being very careful, with a screw driver with the head covered with some layers of tape to prevent damage to the board. But, really, get an IC removal tool, they’re cheap.

Then it’s just a matter of popping in the new V4.4 EPROMs (align the notch on the EPROM with the notch on the socket!): The “LSB” EPROM goes into the socket marked “IC9” on the board, the MSB EPROM goes into the “IC10” socket.

Switching the Akai on again, it says “Operating System 4.40” at the bottom of the screen. Success!

For more Akai S1000 related posts, check the akai s1000 tag, for more posts from my summer vacation tinkering project, check the summer of samplers tag.