Forums

crazy memory ideas?

Started by Joseph H Allen November 6, 2013
JL > We could distribute software on vinyl disks,
JL > 45s or LPs. We'd have to agree on a coding format.
 
Shades of Tarbell interface!
 
A Minneapolis Radio computer talk show in the 1980's
actually broadcast a lot of software for various
computers and the interface they sold was not
terribly expensive.
 
Computer magazines also published binary software
that could be scanned from the page by some of the
scanner gadgets at that time.
 
Univac sold HUGE magnetic drum storage units that
used ferrous oxide coating and magnetic heads
very much like common hard disk drives today.
Apparently this type of storage was fast enough
that it could be used in ways more traditionally
thought of as a job for core memory or RAM memory.
 
I heard that people working around them didn't
want to think about what would happen if the
bearings went out or the huge spinning drum
were to ever break loose at speed.
 

 
On Wed, 06 Nov 2013 21:47:37 -0800, Kevin McMurtrie
<mcmurtrie@pixelmemory.us> wrote:

>In article <l5drek$uc8$1@pcls7.std.com>, > jhallen@TheWorld.com (Joseph H Allen) wrote: > >> Well here is one: Use a selenium-coated laser printer drum pretty much as >> intended. Impart a charge on it's surface, fire laser to erase charge for a >> 0 or leave it for a 1, then use some kind of electrometer to read the bit >> later. Recycle this back to the laser for recirculating memory. >> >> I'm wondering if there is any way to make a large scale CCD shift-register >> memory which can be made at home. I'm imagining tin-foil electrodes glued >> to some kind of reasonably high-mobility but fully-depleted material.. but >> is there such a material besides a single-crystal semiconductor? >> >> Hmm, which reminds me: does anyone have a good description of how >> bucket-brigade devices really work? The equivalent schematic the datasheets >> always show can not possibly work (the mosfet switches will cause charge to >> be shared between the two capacitors they connect, and not moved in one >> direction: you would need buffers between stages for the discrete device >> version of this to work). > >Some early memory designs had a rotating loop of magnetic wire. If you >wanted to access address X, you waited X*bits clock cycles after the >sync marker then read or wrote bits. Memory density wasn't too bad for >that era but latency was awful.
Mercury filled tubes were used in early (1940's) computers to send acoustic waves through the tube and after regeneration sent back to form a shift register, with the same limitations as a rotating drum or disk storage.
>Scientists have tried similar tricks sending light pulses around loops >of fiber optic cable. It works with all the same limitations as the >loop of magnetic wire. There's also short-term storage using piezo >elements that bounces mechanical waves through a little plate of quartz.
The most common application for this was in PAL colour television (hundreds of millions of sets) in Europe, which required a one horizontal line (64 us) delay with approximately 1 MHz bandwidth.
>Longer term storage can be performed by sending mechanical waves through >long coils of spring wire, like old guitar amps that have a reverb >effect. Ultra-short storage uses bits of coax cable.
You could use a TV satellite transponder with perhaps 200 Mbit/s throughput as a shift register memory. With 250 ms round trip delay, this ring could store about 6 Mbytes. Of course, there are cheaper means to store that amount of data :-). However, 14" single platter disk drives with similar capacity were used in the 1980's.
On Wed, 6 Nov 2013 22:19:43 -0800 (PST), Greegor <greegor47@gmail.com>
wrote:

>Univac sold HUGE magnetic drum storage units that >used ferrous oxide coating and magnetic heads >very much like common hard disk drives today. >Apparently this type of storage was fast enough >that it could be used in ways more traditionally >thought of as a job for core memory or RAM memory.
The main advantage of drums vs. disks was that you more or less had to use a separate head for each track, while in a disk drive you could move the read head from track to track, causing the seek time. With a rotating device, you must be very careful how you store the data. If you put data in every block, reading and processing a block may take too long, so that the next block is lost and you have to wait a full rotation until getting the next block. However, if you put the data in every other block thus the first part in odd blocks and the rest in even numbered block, after reading the first block, you have the full memory rotation block time to process the data, before processing the next block. This assumes sequential program execution. In floppy disks a similar method was used.
On 11/07/2013 02:04 AM, upsidedown@downunder.com wrote:
> On Wed, 6 Nov 2013 22:19:43 -0800 (PST), Greegor <greegor47@gmail.com> > wrote: > >> Univac sold HUGE magnetic drum storage units that >> used ferrous oxide coating and magnetic heads >> very much like common hard disk drives today. >> Apparently this type of storage was fast enough >> that it could be used in ways more traditionally >> thought of as a job for core memory or RAM memory. > > The main advantage of drums vs. disks was that you more or less had to > use a separate head for each track, while in a disk drive you could > move the read head from track to track, causing the seek time. > > With a rotating device, you must be very careful how you store the > data. If you put data in every block, reading and processing a block > may take too long, so that the next block is lost and you have to wait > a full rotation until getting the next block. > > However, if you put the data in every other block thus the first part > in odd blocks and the rest in even numbered block, after reading the > first block, you have the full memory rotation block time to process > the data, before processing the next block. This assumes sequential > program execution. > > In floppy disks a similar method was used. >
http://www.cs.utah.edu/~elb/folklore/mel.html Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
In article <l5e02o$37q$1@pcls7.std.com>,
Joseph H Allen <jhallen@TheWorld.com> wrote:
>Oh, another one I want to try is to make an acoustic delay line: but I want >to run it at audio frequency and use the air as the delay line.. (instead >of wire or crystal), so that you can listen to it..
I tried this: here's a video: https://www.youtube.com/watch?v=a5hOmPdxw0U -- /* jhallen@world.std.com AB1GO */ /* Joseph H. Allen */ int a[1817];main(z,p,q,r){for(p=80;q+p-80;p-=2*a[p])for(z=9;z--;)q=3&(r=time(0) +r*57)/7,q=q?q-1?q-2?1-p%79?-1:0:p%79-77?1:0:p<1659?79:0:p>158?-79:0,q?!a[p+q*2 ]?a[p+=a[p+=q]=q]=q:0:0;for(;q++-1817;)printf(q%79?"%c":"%c\n"," #"[!a[q-1]]);}

upsidedown@downunder.com schrieb:

> Mercury filled tubes were used in early (1940's) computers to send > acoustic waves through the tube and after regeneration sent back to > form a shift register, with the same limitations as a rotating drum or > disk storage.
Hello, they did that not only with mercury filled tubes, but also with solid metal wires wound to a spiral and carefully suspended in slots cut into sheet metal stripes. The suspension of the wire did not disturb the ultrasonic waves travelling through the wire. Bye
On 11.11.13 11:44 , Uwe Hercksen wrote:
> > > upsidedown@downunder.com schrieb: > >> Mercury filled tubes were used in early (1940's) computers to send >> acoustic waves through the tube and after regeneration sent back to >> form a shift register, with the same limitations as a rotating drum or >> disk storage. > > Hello, > > they did that not only with mercury filled tubes, but also with solid > metal wires wound to a spiral and carefully suspended in slots cut into > sheet metal stripes. The suspension of the wire did not disturb the > ultrasonic waves travelling through the wire. > > Bye >
The British Elliott 803 used nickel wire spiral delay lines for registers, and ferrite memory rings for logic (and for memory as well: 8192 words of 39 bits). It was not blindingly fast: 288 us per machine cycle. -- Tauno Voipio
On Thu, 7 Nov 2013 04:14:43 +0000 (UTC), mroberds@att.net wrote:

>John Larkin <jlarkin@highlandtechnology.com> wrote: >> We could distribute software on vinyl disks, 45s or LPs. We'd have to >> agree on a coding format. > >There is another theory, which states that this has already happened. >http://en.wikipedia.org/wiki/File:FloppyRom_Magazine.jpg > >> You could melt pits into the surface of wax or ice with a laser, and >> read it back with a lower power laser. Bulk erase. > >Why did my read error rate go up when I moved from Toronto to Phoenix? >:) > >Matt Roberds
Lower local literacy rate? ?-)
On Thu, 7 Nov 2013 04:14:43 +0000 (UTC), mroberds@att.net wrote:

>John Larkin <jlarkin@highlandtechnology.com> wrote: >> We could distribute software on vinyl disks, 45s or LPs. We'd have to >> agree on a coding format. > >There is another theory, which states that this has already happened. >http://en.wikipedia.org/wiki/File:FloppyRom_Magazine.jpg > >> You could melt pits into the surface of wax or ice with a laser, and >> read it back with a lower power laser. Bulk erase. > >Why did my read error rate go up when I moved from Toronto to Phoenix? >:) > >Matt Roberds
Why would any sane person move to Phoenix? -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
On 11/12/2013 2:14 PM, John Larkin wrote:
> On Thu, 7 Nov 2013 04:14:43 +0000 (UTC), mroberds@att.net wrote: > >> John Larkin <jlarkin@highlandtechnology.com> wrote: >>> We could distribute software on vinyl disks, 45s or LPs. We'd have to >>> agree on a coding format. >> >> There is another theory, which states that this has already happened. >> http://en.wikipedia.org/wiki/File:FloppyRom_Magazine.jpg >> >>> You could melt pits into the surface of wax or ice with a laser, and >>> read it back with a lower power laser. Bulk erase. >> >> Why did my read error rate go up when I moved from Toronto to Phoenix? >> :) >> >> Matt Roberds > > Why would any sane person move to Phoenix? > >
Because the weather in Toronto is even worse, though in a very different way. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net