TEAC FD-55GFR = Quad Density?

[Dave Dunfield]

At 19:15 07/10/2005, you wrote:
>  I found a pair of these drives and picked them up since my reference said
>that they were quad density drives AND they had DS-QD disks in them.
>However I looked on the net and found that everyone including Teac's site
>says that they are HD (1.2Mb) drives. Which are they? I THINK these have a
>jumper that chages the speed from 360 RPM to 300RPM. Will this make the
>drive a QD drive? I thought the heads needed to be differnt since the
>magnetic media on the disks have different permeability.
>
>    Joe

One of my favorite FDDs.

These will do either HD or DD (called QD because it is 80 tracks).

The recording density (HD or DD/QD) is defined by interface pin #2.

'LG' strap ON :  Pin2 Hi = DD/QD, Pin2 Low = HD
'LG' strap OFF:  Pin2 Hi = HD, Pin2 Low = DD/QD

You also need to run the drive at 300 RPM in you are using a
standard 250khz transfer rate controller -  To do this, put
strap 'I' ON - this will run at 360 during HD operation, and
300 during DD/QD operation - with 'I' OFF, the drives runs at
360 rpm all the time.

NOTE: A PC controller transfers data to HD drives running in
DD/QD mode at 300khz, which means that PC drives always run at
360rpm - but for a non PC/HD controller, the data rate will be
250khz, and you need to jumper the drive to run at 300rpm.

Dave
-- 
dave04a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Collector of vintage computing equipment:
                http://www.parse.com/~ddunfield/museum/index.html