View Full Version : Iso: Tms9909 fdc ic

November 25th, 2011, 09:11 PM
I've got one glaring gap in my collection of floppy controllers and that's the TMS9909. I know that they were used on the Powertran Cortex for a time, but I'm not aware of any other application.

Is anyone aware of a sample of the IC for sale?


November 26th, 2011, 09:56 AM
Chuck, I have a few of these that I bought for my Cortices a couple of years back. They were extremely difficult to find and I've been trying to reserve them for use in Cortices. One note: it appears that TI may never have produced the chip in the TMS9909 packaging (the most recent guaranteed 9909s that I've found bear the TMX9909 labeling). I do have a few extras that I got from China a while back that purport to be TMS9909s, but I haven't gone and tested one of those yet (and I can part with one of these if you're interested--I got them for about $22 each).

November 26th, 2011, 10:03 AM
Thanks--I'm a little gun-shy of the Chinese stuff. High-value vintage chips are quite often counterfeit in my experience when purchased from Chinese suppliers.

According to the discussion over at CPU-World, the "TMX" marking denotes a prototype, pre-production model. That usually means bugs.

But I'll keep your offer in mind!

November 26th, 2011, 03:31 PM
You're correct on the pre-production moniker--and I generally have the same qualms with Chinese-sourced parts, which is why I haven't tested one yet. I wanted to have a spare Cortex board assembled to do the test on so that it had no chance of trashing my primary system. . .I just got a pair of Cortex boatds to build, so that will allow me to do the tests soon.