The good old days... I recall the Q-7 drums would take about 15 minutes to come to a stop when turned off, and would power up in seven seconds or less. Surge current was around 115 amps?
Paul On Thu, May 10, 2018 at 3:46 PM, Mike Loewen via cctalk < cctalk@classiccmp.org> wrote: > On Thu, 10 May 2018, Al Kossow via cctalk wrote: > > On 5/10/18 10:37 AM, Al Kossow via cctalk wrote: >> >>> >>> >>> On 5/10/18 9:29 AM, Paul Koning via cctalk wrote: >>> >>> 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. >>> >> >> Just checked, and the LGP-30 and RPC-4000 drums are both listed as 3600 >> rpm >> > > 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 mloe...@cpumagic.scol.pa.us > Old Technology http://q7.neurotica.com/Oldtech/ >
