Vintage Computing – part 2

Posted by: Rea Maor In: Hardware and Gadgets - Tuesday, April 24th, 2007

We have arrived in the glorious era of Big Iron. The large mainframes and the era of DEC, the Digital Equipment Corporation, ushered in the first major computer boom from about the mid 1960’s to the mid 1970’s. These are now known collectively as the second-generation systems, when computer interfaces slowly adapted from the punched card to the teletype and terminal, but before the first “desktop” microcomputer came out. Famous for huge reels of tape and rooms with raised white floors and industrial-strength air conditioning. If you, during the late 60’s and early 70’s, saw the inside of one of these “dinosaur pens”, as they are now called, you were most likely either in college or had an interesting job in the aerospace industry. And whatever you do, don’t hit that big red switch by the door; that dumps the Halon.

PDP 10

The Languages: Besides the assembly language specific to hardware, three main general-purpose programming languages arose during this era; COBOL, FORTRAN, and LISP. I said “main”; but we know about ALGOL, PL/1, and others as well. COBOL is considered dead and buried, unless you end up maintaining an ancient mainframe system running an actuary table or a ballistics calculator in an old insurance company headquarters or military base. Y2K was almost the final death blow for COBOL.

Both Fortran and Lisp can be compiled and run today on a number of software products. Fortran is actually still maintained as part of the GNU Compiler Collection, which has been ported to most modern systems (as gcc on Unixen, DJGPP on Windows and DOSen, etc.) As for Lisp, take your pick; Lisp has hundreds of little fractured sub-dialects running around out there with variations of CMU Lisp, Common Lisp, and Scheme. Perhaps the most readily accessible interpretation is “eLisp”, the implementation found in the cross-platform Emacs editor.

eLisp in Emacs

CLisp, an ANSI Common Lisp interpreter, is also available for multiple platforms.

CLisp in a terminal

The Machines: Are you an ITS hacker? Did you cut your teeth on a PDP-10? Do you still remember how to boss a VAX around? Can you recite the “Blinken-Lights” sign from memory? Then you’ll be interested to know about the SIMH project…

SIMH is the Computer History Simulation Project software to emulate numerous Big Iron machines of yesterday on the computers of today. If you follow the link, you will find both Windows system executable programs and source code for other platforms. These instructions worked for compiling to a POSIX environment.

The SIMH system boasts a crazy collection of PDPs, VAXs, IBMs, an HP or two, and many others. It may seem strange that we can run so easily a formerly huge mainframe operating system inside a window on our modern desktop that takes up only a few MB of memory, but keep in mind that those mainframe machines of the 60’s and 70’s were impressive in size only; they had less power than a modern cell phone!

A PDP11 simulation

Various machines emulated through SIMH also run programming languages for their time period. So your old ALGOL code may yet find life in the HP 2100 simulator. Just be prepared to surf through the documentation on the site; no matter how familiar you were with the older boxes, you’ll likely have a hard time remembering exactly how to do stuff on them like read and edit files. If you catch yourself reaching for the mouse while running SIMH, you’re having a bout of culture shock.

The Actual Hardware: Now here, we’re talking about a taste a little harder to gratify. It’s one thing to emulate the software on your desktop, quite another to have the physical beast itself running at home (and probably dimming the lights when you turn it on).

Many of the machines from this time period are on display and maintained at the Computer History Museum in Mountain View, California. In addition, several machines still exist in odd pockets around government and big business institutions. With some of these machines, the owners and maintainers are more than happy to get rid of, as this humorous posting to the “scary devil monastery” (alt.sysadmin.recovery) shows. The occasional auction or message board exists for hobbyists – you’re almost guaranteed to find one if you search Usenet. And of course, lore of this period and links to hobbyist groups still thrives on the infamous Jargon File, maintained by Eric S. Raymond. Yet another pointer is 36bit.org, which has much information on the machines of the DEC, GE, Honeywell, and early IBM era, as well as links to collector sites and hobbyist web-rings.

But perhaps your tastes run slightly more recent. Maybe you miss the glory days of the great Amiga and BeOS, or you’re hankering to re-live your BBS days, or maybe you’re just itching to see what a BASIC program running on an AppleII looks like again.

Stay tuned for the next episode…

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