PCs that support only one floppy drive in hardware - test-drb@ccmp.vtda.org

13 Oct 2005

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Subject: Re: PCs that support only one floppy drive in hardware
   From: ard at p850ug1.demon.co.uk (Tony Duell)
   Date: Thu, 13 Oct 2005 10:39:21 +0100 (BST)
     To: cctalk at classiccmp.org

  The
_drive_ is HD, I am not sure what the controller can do, though. The 
suffix letters of Teac drive numbers seem to indicate the specs as 
follows : 

A : 40 cylinder single-sided
B : 40 cyclinder double sided
C : 77 cylinder single sided (??? I have never seen this)
D : 77 cylinder double sided (??? or this)
E : 80 cylinder single sided
F : 80 cylinder double sided  
 300 rpm only

 G : 80 cylinder double sided, 360RPM, high density
(1.2M for PCs)  
 Does both 300 and 360. (can replace the E and F with correct jumpers). 
I am not convinced of that. I think 'G' implies 360RM. The drive in 
question is a 'GFR', thus having the capabilites of both the 'G' and the 
'F', in other words both 360 and 300 rpm. 
I am certain of the GFR, I have maybe 8 spares and 5 in use to confirm it 
with. Dec use that drive in the VAXMATE at 1.2mb and as RX33 in uPDP-11
at 400/800KB (low speed) units I've used for both are exact same units.
one oddity of the FD55GFR series is I have at least 5 different PC board
patterns that function the same, they are of different date codes. 
I have also used them in my S100 system for the infrequent DSQD 780kb
CP/M format that is  compatable with my Kaypro 4/84 with Advent turborom.
I also have a supply of FD55B, E and F series drives as spares and in 
use My three Visual 1050s have the FD55E in them. My knowledge is first 
hand. 

Read the data for that drive and you will see that FD55GFR is a DUAL 
speed drive.

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   H : 80 cylinder double sided, 300RPM, high density
(1.44M for PCs)  
  Never seen an FD55H. 
No, but the same suffix letters are used on 3.5" drives too. 
I would have guessed it was 3.5" too.

Allison