The Computer Collection:

Digital Equipment Corporation - PDP 11/03)

I have several example of the pdp-11. All are variations of the lsi-11/2 and lsi-11/23. I haven't been luck enough to find a unibus machine with actual blinkenlights just yet. The first 11/03-l came from Lord Corporation in Saegertown, Pa. where it was part of a color matching system used in the production of dye, paint, and plastic pellets. They sold me everything but the actual color scanner for the princely sum of $100. This particular example has 32K of memory, the extended instruction set (EIS) option, dual RX02 disk drives, an LA-120 Decwriter, and a VT-100 CRT. The system runs RT-11 version 04.00C (single job version) and includes the Fortran compiler and MACRO-11.

System number two is a lone CPU, I presently have it hooked up to a DEC PC 486 that provides TTY emulation, a cross-assembler and facilities for loading and saving programs as core images. It’s an exercise in “bare knuckles” computing with no operating system per se, but programming in pdp-11 assembly language, or even raw machine language, isn't as bad as you might think. I actually like to use this system as my testbed -- if I can write a program for this machine (sans peripherals and operating system) I can usually get the same program to run on the other systems.

System number three is a pdp-11/23+ that I acquired via an eBay auction. I actually got three CPU's that were once used to control a General Electric trunked radio system. Since I was rapidly running out of space in my workroom, I donated two of these to a worthy cause and kept the third for my own amusement. I really don't like the memory management on this system since it seems like such work. I run an ancient version of Unix here and it reminds me why I never liked Unix to begin with!

Click here for more information about the pdp-11 systems.

(Digital DEC 3000 Model 700 Server)

This is another Unix system. It runs NetBSD 4.0 (the current distribution) and is the only "classic" machine that's actually on the net right now. Although the early DEC Alpha systems were primarily intended for the workstation market, they sold the machines without the video display boards, keyboards, or mice and called them "servers." That's what this system is. They keyboard and video display terminal shown are actually another product entirely, a DEC (Boundless) VT-520 terminal.

Even in the "server" configuration, this system is very capable. It supports the Apache web server, Lynx browser, FTP client and server, NNTP, Telnet, and of course, email. Aside from not having the rat-driven user interface and the pretty pictures, it's actually a very useful internet appliance.

Click here for more information about this system

(IBM System/36 -- Model 5360 System Unit)

Some people might call this one a mainframe -- IBM officially calls it a “midrange” system. I’m going to call it a “minicomputer” based on its lineage, its 16 bit word-size, and the fact that it fits in my living room. Right now, the system powers up and halts with a “console check.” That might have something to do with the fact, that I don’t have a console for it. Both the CSP and MSP appear to be executing instructions. The main storage works and the hard disk is able to spin-up and seek. According to my personal standards, that means that it still works. I’m still looking for some peripherals for it and I hope to have it 100% operational in fairly short order

My system was owned by the Masonic Home of Utica, New York. It appears to have been built in 1985 and was retired in 1989 when they replaced it with an early AS/400 system. The system was stored in a warehouse until March 2002 when I was able to purchase it via an eBay auction.

(Digital Equipment Corporation -- Vax 6000 Model 510)

Despite its heritage as a minicomputer, (sometimes called a “super mini”) this particular Vax cluster counts as a mainframe in my book: Dual 6510 Processors, 128 megabytes of memory per CPU, 20 large capacity disk drives, two HSC control units (each of which is a computer in its own right), a 9 channel tape drive, a big-honking’ line printer, and literally tons of cables, documents, and software. It didn’t fit in my living room. I stored the 18,000 lbs worth of computer for six months inside a storage container in my side yard. Then, unfortunately, circumstances forced me to find a new home for the Vax.

(Standard 80 Column Punch Card)

The standard IBM “Tab Card”: Once upon a time, it was the single most common artifact representing the information age. Punch cards are an icon of automated data processing that dates back to the 1890 census. Nowadays, the punch card is probably most known as part of the “punch line” in jokes about the presidential election of 2000. Still, no computer collection could ever be complete without this ubiquitous archetype of late 19th century technology. Just like the telegraph, the steam engine, and the Colt 45, the punch card is part of our culture and heritage as Americans. Its influence on our society will be felt long after the last card crumbles to dust.

(IBM Model 024 Card Punch)

Like the punched card itself, the Card Punch is an American Classic. Early Hollerith Cards were punched by hand using standard ticket-punching apparatus just like the railroad conductors used. Later, coded punches were constructed that could record numerical or alphabetic information in the cards. By the 1930’s, an entire range of ADP equipment was built around the punched card: punches, verifiers, sorters, calculators, printers, and accounting machines. A specific machine was available to do almost any data processing task -- general purpose computers would later make these dedicated machines obsolete, but it would take the next 30 years to make computers as economical as these “tab shops.”

(Teletype Model 33 ASR)

When interactive computing became a reality, first on time-shared mainframes and later on smaller minicomputers, the user typically interacted with the system via a hard-copy terminal like the Teletype shown here. Even later, when microcomputers like the Altair appeared, the Teletype gave you an input device, an output device, and mass-storage in one neat (and fairly inexpensive) package.

(Commodore KIM-1 Single Board Computer)

Well, this is definitely a microcomputer: 6502 microprocessor, 1024 bytes of MOS RAM, 1 MHz clock, 6 digit LED display, a hexadecimal keypad, and a 20ma current loop interface for the teletype. Not much to look at, but you wouldn’t believe what it could actually do! MOS Technology built it to demonstrate the 6502 MPU. When Commodore bought MOS, this became the very first “Commodore” computer and started a line that would produce the PET, VIC-20, C-64, C-128, and eventually the Amiga. A very proud lineage for a very humble machine.

This page last revised May 13, 2009 by Micheal H. McCabe.