10 May
2018
10 May
'18
1:46 p.m.
On Thu, 10 May 2018, Al Kossow via cctalk wrote:
On 5/10/18 10:37 AM, Al Kossow via cctalk wrote:
The drums on the SAGE system (12 on each side), are listed as follows:
Diameter: 10.7"
Width: 12.5"
Weight: 105 lbs (cylinder, only), 450 lbs for entire drum assembly
Speed: 2914 rpm
Heads: Up to 12 R/W bars, with up to 40 heads on each bar, 1 erase bar
6 pairs, one for Compuuter-to-Drum (CD), one for
Other-than-computer-to-Drum (OD)
Head spacing 0.3" apart on each bar
Drum Layout: 2048 registers on 33 channels (tracks), 6 fields
Channel spacing is 0.050"
Access Time: Maximum 20ms, average 10ms
Write Current: 110ma
The R/W bars are arranged in pairs (CD and OD) so that I/O devices can
access the drum independently of the computer.
More than you ever wanted to know about SAGE drums (thanks, Al!):
http://bitsavers.org/pdf/ibm/sage/3-42-0_Drum_System_Sep58.pdf
Here's one of the earlier style R/W heads:
http://q7.neurotica.com/Oldtech/SAGE/DrumHead-1L.jpg
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://q7.neurotica.com/Oldtech/
On 5/10/18 9:29 AM, Paul Koning via cctalk wrote:
Just checked, and the LGP-30 and RPC-4000 drums are both listed as 3600 rpm One that comes to mind is the DEC RS04. It spins
at roughly 3600 rpm (a hair less, so obviously a 2 pole induction motor running off
3-phase 60 Hz power).
Vermont Research drums (model 1175B) spun at 3450 rpm 3ph
220v, The HP 2773 on the 2000A TSB was from VR so I expect RPM
would be similar for most drums of similar diameter. 