FDN303 datasheet

[Mike Stein]

----- Original Message ----- 
From: "Al Kossow" <aek at bitsavers.org>
To: <cctalk at classiccmp.org>
Sent: Tuesday, September 13, 2016 6:29 PM
Subject: Re: FDN303 datasheet


> 
> 
> On 9/13/16 1:29 PM, Mike Stein wrote:
>> By any chance does anyone have (or know where I could find) a datasheet for an FDN303 LSI chip used in a number of floppy drives? 
>> 
>> Lots of tantalizing links in Google but the ones I followed all lead nowhere...
>> 
> 
> you're going to have a really tough time finding tech data for any Japanese ASIC
========
So I've found... ;-)
========
 > it looks like it is a Panasonic part (most of the hits on FDN303 are for the Fairchild smt part)
> used in an NEC FD1231H
> 
> about the only thing I see are mods for using them on Amigas
========
I should have said the links lead nowhere that's relevant...

As a matter of fact I am playing with some NEC FD1231T's, trying to modify them for 8" emulation (1.2MB mode); I had read some of the Amiga mod articles and they were a little help although they don't address the speed issue and the DC on pin 2 mod doesn't apply.

Fortunately I found the NEC's motor speed control is labelled on the inside of the motor, so maybe I've got enough info to make it work.

That also tells me the speed control pin of the FDN303 (pin 38) which may come in handy on other drives.

It'd still be nice to have a datasheet though.

Thanks, Al!

m