TEAC FD-55GFR = Quad Density?

[Tony Duell]

> 
>   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.

They are both quad desinty and high density. The 'G' in the model number 
means high density, the 'F' means quad density (80 cylinder, double sided).


> 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

They do.

Howeve, a PC/AT contorller can do the 300kbps data rate. That was 
officially to allow the high density drive to read the 360K 
double-density disk, but rememebr that disk only had 40 cylinders, so the 
head was double-stepped as well. If you use that data rate (or slow the 
motor down to 300 rpm) and use all the cylinders (don't double-step), you 
get a quad-density drive.

> drive a QD drive? I thought the heads needed to be differnt since the
> magnetic media on the disks have different permeability.

No, the heads are the same. The write current is different, but that 
drive can do both write currents, controlled, IIRC, by pin 2 on the 
interface connector.

-tony