| Author |
Message |
State Machine
Janitor
Joined: Apr 17, 2006
Posts: 2810
Location: New York
Audio files: 24
|
|
|
Back to top
|
|
 |
JovianPyx
Joined: Nov 20, 2007
Posts: 1988
Location: West Red Spot, Jupiter
Audio files: 224
|
 Posted: Mon Oct 27, 2008 11:47 am Post subject:
|
  |
|
I'm old enough to have actually worked with core memory. At DEC, I had one customer with an old 11/45 that had core AND CMOS RAM. The CMOS wasn't cache, but was managed by the OS to keep the most often used code there. I had to revive that system after a lightening strike.  I also worked on a PDP-8 or two that had core. We had a core plane for most systems that had preloaded diagnostics in them.
Those were the days when bits were big enough to see.
_________________
FPGA, dsPIC and Fatman Synth Stuff
Time flies like a banana.
Fruit flies when you're having fun.
BTW, Do these genes make my ass look fat?
corruptio optimi pessima
|
|
|
Back to top
|
|
|
urbanscallywag
Joined: Nov 30, 2007
Posts: 317
Location: sometimes
|
| Posted: Wed Oct 29, 2008 9:22 pm Post subject:
|
|
|
| ScottG wrote: | | Those were the days when bits were big enough to see. |
 |
|
|
Back to top
|
|
|
State Machine
Janitor
Joined: Apr 17, 2006
Posts: 2810
Location: New York
Audio files: 24
|
| Posted: Sat Nov 01, 2008 11:27 am Post subject:
|
|
|
| Quote: | | 'm old enough to have actually worked with core memory. At DEC, I had one customer with an old 11/45 that had core AND CMOS RAM. The CMOS wasn't cache, but was managed by the OS to keep the most often used code there. I had to revive that system after a lightening strike. Shocked I also worked on a PDP-8 or two that had core. We had a core plane for most systems that had preloaded diagnostics in them. |
Yes, those memories of Core memory. I remember working on radar video signal processors many years ago that had a [1K x 16] magnetic CORE memory installed in it for program storage. As you may recall, CORE memory, when reading a logic "1" from any cell is a destructive read meaning that if a logic "1" is read, it will be flipped to a logic "0". Logic had to be in place that when a "1" was read from a cell, it had to be written back after latching the cells contents in semiconductor memory such as a "Flip Flip" or else the next time it's read, a "0" will be read. That would be a disaster. The Core memory drive logic usually handled this and was tricky to troubleshoot when things went wrong as you might imagine.
How intense would it have been to troubleshoot those mercury tanks !!!
Bill |
|
|
Back to top
|
|
|
State Machine
Janitor
Joined: Apr 17, 2006
Posts: 2810
Location: New York
Audio files: 24
|
| Posted: Sat Nov 01, 2008 11:29 am Post subject:
|
|
|
| Quote: | Those were the days when bits were big enough to see.
|
Yes, now you have to bring them out and light an LED to see them.
Bill |
|
|
Back to top
|
|
|
cappy2112
Joined: Dec 24, 2004
Posts: 2498
Location: San Jose, California
Audio files: 2
G2 patch files: 1
|
Posted: Sun Dec 07, 2008 2:51 pm Post subject:
Re: CORE MEMORY ...... A Visual Survey of Vintage Computers
Subject description: A really nice book for computer history buffs ........ |
|
|
_________________
Free Tibet. Release the Panchen Lama from prison. Let the Dalai Lama return to his home. |
|
|
Back to top
|
|
|
State Machine
Janitor
Joined: Apr 17, 2006
Posts: 2810
Location: New York
Audio files: 24
|
| Posted: Sun Dec 07, 2008 4:31 pm Post subject:
|
|
|
Thanks. Absolutely fantastic. The video is so interesting and when the machine is in motion, it's has the appearance of a moving helix. Such a work of beauty, genius, and precision.
I would really like to get out there some day and see some of these great pioneering computing machines. I was aware that the books pictures were taken from computers from this museum. I saw you pictures also. Thanks very much Cappy !!!
Here is a fine book if your interested in the evolution of mans quest for automated computing. It covers from number systems and mechnical computers all the way to modern computing methods.
http://www.amazon.com/Universal-History-Computing-Quantum-Computer/dp/0471441473/ref=sr_1_3?ie=UTF8&s=books&qid=1228692474&sr=1-3
Great stuff ............
Bill |
|
|
Back to top
|
|
|
cappy2112
Joined: Dec 24, 2004
Posts: 2498
Location: San Jose, California
Audio files: 2
G2 patch files: 1
|
| Posted: Sun Dec 07, 2008 4:56 pm Post subject:
|
|
|
| State Machine wrote: |
I would really like to get out there some day and see some of these great pioneering computing machines. I was aware that the books pictures were taken from computers from this museum. I saw you pictures also. Thanks very much Cappy !!!
Great stuff ............
Bill |
Yes- it is like a dream to watch that thing in motion.
I don't think he could have built it with the technology of that time.
When I saw the presentation at the CHM- they mentioned why the Engine was not physically smaller. (I may have mentioned this in the other thread- apologies if I'm putting you to sleep.) Due to the forces exerted when the Engine is put into motion, if any of the pieces were smaller, they could not withstand the stress. Babbage designed "mechanical fuses" so that if anything would break, it would break in known locations, eliminating weeks/months of troubleshooting just to find the broken part.
_________________
Free Tibet. Release the Panchen Lama from prison. Let the Dalai Lama return to his home. |
|
|
Back to top
|
|
|
cappy2112
Joined: Dec 24, 2004
Posts: 2498
Location: San Jose, California
Audio files: 2
G2 patch files: 1
|
| Posted: Sun Dec 07, 2008 5:02 pm Post subject:
|
|
|
_________________
Free Tibet. Release the Panchen Lama from prison. Let the Dalai Lama return to his home. |
|
|
Back to top
|
|
|
State Machine
Janitor
Joined: Apr 17, 2006
Posts: 2810
Location: New York
Audio files: 24
|
| Posted: Sun Dec 07, 2008 5:38 pm Post subject:
|
|
|
| Quote: | Babbage designed "mechanical fuses" so that if anything would break, it would break in known locations, eliminating weeks/months of troubleshooting just to find the broken part.
|
Great forethought right? I mean, the fuses served not only to protect the other mechanics from getting destroyed when something got jammed up, but also was used as troubleshooting aid to find out where the bind occurred. A far cry from trace buffers and variable watching when developing code and using emulators and software simulators.
Another fascinating thing are those Mercury delay line memories used in the first "Univac I" computers. Wow, a serial bitstream from vibrating mercury along a system of plumbing. Vacuum tube sense amplifiers strategically placed to pick up the tiny signals! They look like miniature satellites or some sort of propulsion system. 
Thanks,
Bill |
|
|
Back to top
|
|
|
State Machine
Janitor
Joined: Apr 17, 2006
Posts: 2810
Location: New York
Audio files: 24
|
| Posted: Sun Dec 07, 2008 5:45 pm Post subject:
|
|
|
| Quote: | | A Quarter Century of UNIX |
Well, considering it's contributions to early and modern computing, and the O/S of choice for most internet servers, a worthy read indeed !!!
Thanks ..............
PS: I have many book suggestions if your interested as I have several in my collection that have to do with computing and networking history ,including, the inception of the ARPANET funded by DARPA ............... as many high technology programs were funded by this agency.
Bill |
|
|
Back to top
|
|
|
|
Forum index » DIY Hardware and Software » Microcontrollers and Programmable Logic
FAQ
Calendar
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
Chat Room
