Ensoniq EPS-M OS ROM

Synth Repair
1

I see here:
https://www.syntaur.com/asr-os.html

That Syntaur has the version 2.40 EPROM for the EPS keyboard, but not for the EPS-M.

My question(s) would be, a) does a 2.40 OS for the -M exist? And if so, b) does anyone have any idea where I might be able to get one? For that matter I’d be willing to buy a prommer and burn it myself if anyone knows where I could download it.

Also just curious, do we know for sure the keyboard version wouldn’t work in the -M?

Reason being, I’m trying to get a SCSI2SD device working. Right now I’ve got both an -M at OS 2.21, and a keyboard at OS 2.40. The SD device works perfectly on the EPS keyboard. But on the EPS-M, I can only seem to get it to work if I limit the partition to 165MB, and the EPS won’t boot from the SD device. I’m assuming these limitations are due to the 2.21 OS, so I’d really like to upgrade it if possible.

2

The latest OS Ensoniq released for the EPS-M was 2.41, while the latest for the EPS was 2.40. That would indicate to me that they are not cross-compatible. And since the EPS requires 2.40 to work with SCSI, I’d bet that updating your EPS-M firmware to the latest version would then give it better SCSI capabilities. We don’t see EPS-M’s very often, and we don’t have the firmware for them. So hopefully someone out there will have it…

The EPS was designed right around the time that SCSI was being born, so the EPS SCSI implementation is rather crude. It got better with each subsequent sampler (EPS-16 Plus, then ASR-10).

3

Thanks, Sam. Yeah, it would make sense that they’re not compatible. I imagine the keyboard OS has code to deal with the keyboard that might cause issues in -M, and so forth. Hopefully someone out there has a 2.41 eprom.