My Background Is Real :-)

 

(you can click on most of the equipment above to go to the section that describes it)
(devices added after this page was last updated can be found here)

The first three computers are reproductions of computers that have sentimental value for me (all function just like the originals - same software and timing). There are two tape drives: The Teletype is an ASR-33 (probably the most popular model that Teletype ever made). Note that this terminal only had UPPER case letters! The ASR-33 ran at 10 characters/second (110 baud) and could read and punch paper tapes. Trivia: The ASCII delete character is 0x7F because it allowed any character on a paper tape to be deleted by punching all 7 holes (paper tapes are 8-bits wide, but ASCII was a 7-bit code).

The black device with the red stripe above the paper tape drive is a Memorex 550 8" floppy drive that could store 1.2MB on an 8" double sided double density 8" floppy. This drive is the actual drive that I used on a computer back in the early 1980's. The little notch on the bottom right is for write protect (covered with light-tight tape was write enabled, open was write protected).

The plugboard is from an old IBM computer. For more information about plugboards check out Wikipedia and this site. My first job was working in a school datacenter; we used punchcards for attendance (among other things). We programmed plugboards to sort/select attendance cards based on what we wanted to know.

The core memory board is from an unknown computer and is 256 bytes (yes BYTES) of memory (see Wikipedia)! Each bit is a single ferrite bead (magnet). These were hand woven. Each of the 8 blocks is an array of 16x16 (256) beads. Core memory has the neat property that it is non-volatile (values in memory remain when the computer is powered off). Trivia: "core" files are called core files because early computer systems would save a copy of what was in memory (core) in a file after a crash.

The HP25C was the calculator that I really wanted (but never got in college).  Three or four years after college I was chatting with a friend (Charlie Elliott) one day and mentioned the HP 25C - a few years later Charlie found one at a yard sale and sent this one to me :-)

For those old enough to remember, the slide rule was the "mechanical calculator" that was in common use before electronic calculators.  I've had this one for a long time and I had a circular slide rule in my car for many years to calculate gas mileage before cars did it for you.....

Edison bottles are not really computer tech, but they are cool, so I have a couple displayed here :-)

The tape drives and teletype aren't connected.....yet.

On the rack behind the Teletype are paper tapes, DECtapes and 9-track tapes. The red write ring was placed in the back of a 9-track tape to write-enable the tape.

The vacuum tubes (aka valves) are actually old radio tubes, but are similar to the tubes used in early computers (before transistors, which were before IC's). See Wikipedia for more information about vacuum tube computers.

3D Printed IMSAI - a gift from my wife - those of you who know me know about my IMSAI and our first date....

Vacuum tube robots - a gift from my wife

The candlestick phone is an original phone from the early 1900's. It's marked "Western Electric, Made in USA" and lists three patents dated Aug 16, 04, Sep 13, 04 and Jan 26, 15. It's relatively heavy just under 4 pounds (1.8 kilos). This particular phone has sentimental value because I found it in my grandfather's basement after he died. My grandfather ran a radio/TV repair shop in Boston from the 1920's to the early 1970's.Sam's Radio Stores Label.

Additional Reading:

I was Director of R&D at Ithaca InterSystems starting in late 1979. We built/marketed the fastest CP/M system ever sold; we were the first to build/deploy a DMA disk controller (all previous controllers were accumulator transfer), interrupt driven I/O, extended mapped memory (to get around the Z-80 64K address space) which we used for track-at-a-time disk reads and caching. For some long running applications, we took processing time from over 48 hours to less than one hour.

I was the author of the Pascal/Z compiler and later a multipass optimizing compiler for the IBM PC (SBB Pascal); for more info see page 42.

Please send questions/comments/suggestions (or more vintage hardware ;-) ) to jeff@rtr.com.

I'm always interested in finding more vintage computer memorabilia.  Please let me know if you know of any.

I'm particularly interested in old DEC PDP 8 and PDP 11, IBM 370, HP 1000, DG Eclipse, IMSAI 8080 and Ithaca InterSystems DPS-1 related items as they all have some sentimental value, but anything that is old and computer related would be awsome :-)