working magnetic drum stores?

From: Vintage Computer Festival <vcf_at_siconic.com>
Date: Wed Mar 31 20:05:48 2004

On Wed, 31 Mar 2004, Hans B PUFAL wrote:

> Vintage Computer Festival wrote:
>
> >The Librascope L321 fixed-head drive I've got is coated with cobalt
> >according to the literature.
> >
> >
> Deatails please, CCC lists Libbrascope L-300, L-3055, L-3060, LGP-21
> and LGP-30. but no L321.

The label on this is stamped with a model number of L-321-1. I have
literature for the Series L-300 with the following characteristics:

Power requirements: 115-volt, 60-cycle, single-phase AC
Disc diameter: 10 in.
Weight: 25 lbs.
Axis of rotation: Vert., horiz., or any combination
Recording diameters: 4.7 in. to 9.2 in.
Number of tracks: 45 (5 groups of 9)
Number of registers: 4
Register length: 0.25 or 0.5 in.
Register adjustment: +/-0.018 in.
Bits per track (max.): 6144 pm recording
Track width: 0.034 in.
Tracks per inch: 20
Capacity (total): 276,480 bits
Packing density (max.): 400 bits/in. at 4.7 in. dia.
Rotational speed: 1200 or 1800 rpm
Frequency (repetition rate): 184kc (max.)
Recording surface: Proprietary plated cobalt
Head spacing: Flying head
Head inductance (typical): 1 mh/half coil
Write current (typical): 28 ma
Readback voltage (typical) 1200 rpm:
   180 mv (min.), inner track
   340 mv (max.), outer track
Bearing life (average): 10 years

The Model L-323 has the following characteristics:

Power requirements: 115-volt, 60-cycle, single-phase AC
Disc diameter: 10 in.
Weight: 60 lbs.
Axis of rotation: Vert., horiz., or any combination
Recording diameters: 4.7 in. to 9.2 in.
Number of tracks: 135 (15 groups of 9)
Number of registers: 12
Register length: 0.25 or 0.5 in.
Register adjustment: +/-0.018 in.
Bits per track (max.): 6800 pm recording
Track width: 0.034 in.
Tracks per inch: 20
Capacity (total): 1,000,000 bits
Packing density (max.): 400 bits/in. at 4.7 in. dia.
Rotational speed: 1200 or 1800 rpm
Frequency (repetition rate): 204kc (max.)
Recording surface: Proprietary plated cobalt
Head spacing: Flying head
Head inductance (typical): 1 mh/half coil
Write current (typical): 28 ma
Readback voltage (typical) 1200 rpm:
   180 mv (min.), inner track
   340 mv (max.), outer track
Bearing life (average): 10 years

>From the accompanying photo, the L-323 seems to be a three platter device
driven by one motor. My guess is that the L-321 (what I have) denotes the
single platter device.

So L-300 is probably the general series family, and L-321 and L-323 are
the specific product models.

-- 
Sellam Ismail                                        Vintage Computer Festival
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Received on Wed Mar 31 2004 - 20:05:48 BST

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