26 May
2005
26 May
'05
1:26 p.m.
----- Original Message -----
From: "Vintage Computer Festival" <vcf at siconic.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Thursday, May 26, 2005 12:19 PM
Subject: Re: Remembering RAMAC
On Thu, 26 May 2005, Paul Koning wrote:
IBM did have a drum based machine before the 305 Ramac.
I believe the model # was 650 and was also known as a 650 Ramac.
The 305 Ramacs we were installing in CT (1957 into the 60's) were 10MB disks
with avg access time of 600ms.
They were also 'programmed' using plug-in panels, like the EAM machines,
407's etc. and stored code.
Both of these IBM machines still had only punched card input for programs
and transactions.
I can't remember any hard disks greater then 50MB being available even into
the late 1980's.
Al> Or magnetic drums, which did NOT have the
access time problems of
Al> tape or cards (but, unfortunately weren't an IBM invention)
Did the drum come before RAMAC?
Yes. Many years (I believe about six).
An obvious
difference is that drums, being head per track devices,
always had rather low capacity.
And disks are much more efficient than drums anyway.
--
Sellam Ismail Vintage Computer
Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger
http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage
mputers ]
[ and academia at www.VintageTech.com || at
http://marketplace.vintage.org ]