Punch Cards Revisited

In the beginning, there were punch cards.

As far back as Jacquard automating the power loom in the early 19th century, the idea of storing information as a series of perforations in various media was an established idea.   Shiplofters, blacksmiths, machinists, and horologists  used perforated templates to make complex parts.  The concept was known to Babbage and Wheatstone.  Samuel F. Morse used a form of binary code in his telegraph and came very close to modern punched tape with the pen-register for his telegraph.  Gamewell used a notched cam to automate signalling in telegraphic fire alarms. Notched or perforated disks, and later punched paper tape, were used to send “canned” messages via telegraph and early wireless systems.

Even with all of this prior art in mind. Herman Hollerith credited a railroad conductor’s practice of creating a “punch photograph” on train tickets to indicate the biometric characteristics of a passenger as his inspiration for using punched cards to record census data.  His development of tabulating equipment for the 1890 census was to launch the company today known as International Business Machines (IBM) and a method of automatic data processing that ultimately led to the stored-program digital computer.

Hollerith card as shown in the Railroad Gazette in 1895, with 12 rows and 24 columns.

Early forms of punch card storage used primarily the edges of the cards for recording information.  A standard ticket-punch could easily be used to create holes along the edge of the cards and cards could be sorted and selected by various criteria by simply threading a large needle through the deck of cards and “shaking” the deck to remove selected edge-punched cards.  I recall a card-file database using this method in use as late as 1984, used to schedule college classes and ensure compliance with various prerequisites.  Royal McBee was still marketing a commercial version of these cards into the 1970’s.


Royal McBee Card Notching Punch

When Hollerith developed his punched-card system for the 1890 census, he developed not just a single item, but rather a complete system of machines for punching his cards, tabulating census results, and even sorting the cards by various criteria.  The first machine we will consider is the “Pantograph Punch” that enabled the use of holes throughout the interior of the card to represent information, rather than just along the edges.

The Hollerith “Pantograph Punch” developed for the 1890 Census.

This particular punch allowed for the accurate placement of punches in the interior areas of the card and the longer lever made repetitive strain injuries less likely (at the time, what we now know as “carpal tunnel syndrome” was common among telegraphers and similar occupations and was known as having a “glass arm.”)

At this point in the development of punched-card data processing, there was very little in the way of standardized coding.  Individual punch locations were assigned to represent a single binary value such as sex or marital status; complex values like age or race used multiple columns to indicate a range of answers based on yes or no questions.  Census enumerators would punch a card based on original documents collected by field workers.  Batches of the punched cards were then forwarded to the tabulators who used a surprisingly sophisticated electrical machine to compute the totals.

Census Tabulating Machine developed by Herman Hollerith for the 1890 Census. The card reader is on the right side of the desk. A pantograph punch sits of the left side of the desktop.

These machines could tabulate up to forty different values during each pass through the deck.  A plug-board programmer was used to assign each of the clock-like tabulating dials to any of the 288 holes in a standard 12 row by 24 column cards.  The card reader on the right consisted of a “bed of nails” array of rods that were somewhat free to move in the vertical direction.  If a card was perforated in a particular location, the rod would pass through the hole and come in contact with a charged pool of mercury in the base of the reader.  The charge would then be conducted through one of the 288 wires connecting the reader to the plug-board and thence to the selected recording dial on the face of the machine. Totals were then manually recorded on summary forms and stored for later use.

In addition to the machines designed for data collection and tabulation, the original patent included a semi-automatic sorting machine that was typically placed next to the tabulator.  When a card had been read and its contents recorded by the tabulating machine, an electrical signal from the tabulator would trigger an electromagnet in the sorter that would open the appropriate slot into which the operator would insert the card.

Hollerith sorting machine, 1890.

Later developments of this basic system would eventually produce dozens of different machines that would make large-scale automatic data processing a reality during the first half of the 20th Century.

To Be Continued…


Sweet Dreams are Made of This

Today was a (fairly rare) “day off” for both my eldest son (Michael) and I.  Sharon was off babysitting a friend’s children.  Matthew was also here and the three of us were indulging in a nostalgic binge of 1980’s popular music on YouTube.  Eventually, we came upon the 1983 hit by the New-Wave group Eurythmics, “Sweet Dreams (Are Made Of This).” The song is considered a “signature piece” for the Eurythmics and the music video (directed by Chris Ashbrook) is a definitive clip for the early period of MTV.

I’d seen the video before — probably hundreds of times in the last 34 years — and always admired the computer used by David Stewart in the film.  Today, one of the boys asked me “What kind of computer is that?”  I honestly didn’t know — I guess I always wrote it off as either a simple stage prop or a homebrew system from the early 1980’s.  A bit of research on the interwebs found at least one loser that positively identified it as an “Apple I.”  I supposed that was plausible, but with an air date of January 1983, I didn’t think it was likely given the six years that had passed since the introduction of the Apple II and the various trade-in / trade-up programs offered by Apple and various retailers.  Further, it appeared that there were too many dials, buttons, and switches for the average Apple I.  Yes, it has the typical 9″ Monochrome Composite Monitor (as did many systems in the late 1970’s and early 1980’s), a wooden case, and a fairly generic looking ASCII keyboard, but the fit and finish is pretty good for a homebrew system of the period.

Screenshot from 2017-07-20 13:09:06
The mystery machine — 9″ monitor, wooden case, ASCII Keyboard, and a bunch of knobs and switches…

The layout of the knobs suggests an audio mixer of some kind with around 14 individual input channels and perhaps a stereo left/right master volume on the far left… Each channel appears to be neatly labeled as to function, but the resolution of the video is insufficient to read any of them.  There is a symbol of some sort and writing to the left of the keyboard, but again it’s impossible to read in the video.  The knob to the right of the keyboard appears to be a selector switch of some sort, with lines leading to slider switches below it.

Screenshot from 2017-07-20 13:12:38
Computing in the Cow Pasture with the Eurythmics

Given that the machine was being operated (at least in the video) by a musician known for playing synthesizers who was an early adopter of direct digital synthesis, a subsequent Google search came up with several hits for the Movement Systems Drum Computer — Mark I Prototype.  Wikipedia has a short article on the subject, as does the website www.vintagesynth.com.

I’ve been unable to find out many technical details about the system, other than there were very few produced (perhaps 30), it premiered in 1981, the Mark II was introduced in 1983, and a MIDI interface was added sometime in 1984.  The system originally sold for around £2,000.  Other than the Eurythmics, bands using the MCS Drum Computer included Phil Collins, The Thompson Twins, Human League, Thomas Dolby, Kajagoogoo, Japan, Willian Orbit, Chemical Brothers and Vince Clarke.

Screenshot from 2017-07-20 13:08:43
Back in the Board Room – A final Look at the Movement MCS Percussion Computer


  • http://www.vintagesynth.com/misc/mcs_drumcomputer.php
  • https://en.wikipedia.org/wiki/Movement_Systems_Drum_Computer
  • https://www.youtube.com/watch?v=qeMFqkcPYcg
  • https://en.wikipedia.org/wiki/Sweet_Dreams_(Are_Made_of_This)


Digital Equipment Corp. – Digital Linear Tape (DLT)

If your adventures in retrocomputing have taken you down the path towards Digital Equipment Corporation, you will recognize these tape cartridges from the VAX and Alpha systems.  Although many VAX systems were equipped with the more traditional 9-track open-reel magnetic tapes so they could interchange data with other mainframe and super-mini computers, almost every VAX sold had a TK-50 tape drive hidden somewhere in its cabinet, if not bolted to the face of the main cabinet right next to the operator’s console.


Although my first “mini” was a pdp-11, the market was flooded with medium-sized Vaxen in the months leading up to the Y2K non-disaster and I was able to pick up a small cluster of VAX 6000 systems for the grand price of $500.  Hooking these 3-phase monsters up to a residential electrical system was a challenge in itself — one that involved rotary converters to turn the single-phase 60 Hz supply into the three-phase flavor that the VAX wanted.  After watching my electric meter spin out-of-control for a few years (mostly due to inefficiencies in the rotary converter — not the computer), I eventually retired the bulk of the cluster, moving memory cards and CPU’s into a single rack that eventually yielded a Vax 6560 — a model never actually sold by DEC that included a six-processor SMP configuration with 32 megabytes of dynamic RAM per CPU.  I ran the hobbyist version of VMS up until HP started getting weird about the “layered” products like the COBOL compiler and eventually switched the system over to NetBSD.


Frankly, running a VAX without VMS wasn’t much fun and the last real use I got out of the VAX was between 2008 and 2012 when I had a gig writing (and maintaining) a fairly large library of COBOL programs.  People can piss and moan all they want about COBOL and VMS, but when you’re the system administrator and can set things up the “right” way, it really is a solid and reliable combination for old-school data processing.

The VAX started getting flaky in late 2012 and I eventually moved everything over to a DEC 3000 (Alpha) desktop that was set up to dual-boot both NetBSD and VMS.  Running with only one or two concurrent users, the Alpha was just as fast as the VAX. It used very little electrical power, and could sit on a desktop disguised as “just another PC.”  The DEC 3000 also used a member of the same “family” of tapes, the TK-70.


Five years later, I’m finally starting to move stuff off the DEC 3000 and into a Linux machine, a Dell Optiplex 755, that’s easier to find parts for and maintain.  The Dell is equipped with several different interfaces, allowing me to use many of the same disk and tape subsystems that it inherited from the VAX and earlier systems (like the various PDP-11 and PDP-8 systems that spent their final days entertaining me here at paleoferrosaurus.com.)  Still, some of this hardware is nearly as old as I am, and after a half-century is starting to show its age.

My retrochallenge project for April 2017 was the TapeStore server, and this is where I’m starting to archive many of the tapes I’ve collected over the years from these various systems.  The improvement this week, was connecting a DLT 7000 tape drive to the TapeStore server and starting to collect images of the various TK-70, TK-50, and similar DLT tapes in the library.

2017-05-13-132225Unlike the folks in Redmond, who have banished support for magnetic tape from current editions of the Windows Server operating system, the folks who maintain Linux (at least the Ubuntu strain) still manage to keep the SCSI device drivers in the kernal and have left utilities like mt and tar still able to work their magic from the command line.  Other than having some trouble with the naming conventions, I was able to hook up the DLT 7000 and access my old tapes without any difficulty… The following script shows a typical session:

Script started on Sat 13 May 2017 02:08:33 PM EDT
root@alpha:~# pwd
root@alpha:~# mt -f /dev/st0 status
drive type = 114
drive status = 419430400
sense key error = 0
residue count = 0
file number = 0
block number = 0
root@alpha:~# tar -tvf /dev/st0

drwxr-xr-x harve/users 0 2011-05-14 17:55 harve/comp_arch
drwxr-xr-x harve/users 0 2011-05-14 17:55 harve/comp_arch/Homework
-rw-r--r-- harve/users 130145 2011-05-14 17:55 harve/comp_arch/Homework/Homework3.docx
-rw-r--r-- harve/users 17380 2011-05-14 17:55 harve/comp_arch/Homework/Homework5.xlsx
-rw-r--r-- harve/users 20424 2011-05-14 17:55 harve/comp_arch/Homework/Homework4.docx
-rw-r--r-- harve/users 71174 2011-05-14 17:55 harve/comp_arch/Homework/comp_arch_homework.ods
-rw-r--r-- harve/users 77312 2011-05-14 17:55 harve/comp_arch/Homework/comp_arch_homework.xls
-rw-r--r-- harve/users 30152 2011-05-14 17:55 harve/comp_arch/Homework/full_adder.ps
-rw-r--r-- harve/users 31279 2011-05-14 17:55 harve/comp_arch/Homework/half_adder.ps
-rw-r--r-- harve/users 30675 2011-05-14 17:55 harve/comp_arch/Homework/not_gate.ps
-rw-r--r-- harve/users 568 2011-05-14 17:55 harve/comp_arch/Homework/not_gate.v
-rw-r--r-- harve/users 29311 2011-05-14 17:55 harve/comp_arch/Homework/or_gate.ps
-rw-r--r-- harve/users 705 2011-05-14 17:55 harve/comp_arch/Homework/or_gate.v
-rw-r--r-- harve/users 30780 2011-05-14 17:55 harve/comp_arch/Homework/xor_gate.ps
-rw-r--r-- harve/users 716 2011-05-14 17:55 harve/comp_arch/Homework/xor_gate.v
-rw-r--r-- harve/users 753 2011-05-14 17:55 harve/comp_arch/Homework/hw3a.asm
-rw-r--r-- harve/users 14543 2011-05-14 17:55 harve/comp_arch/Homework/P4.asm
-rw-r--r-- harve/users 521 2011-05-14 17:55 harve/comp_arch/Homework/squares.txt
drwxr-xr-x harve/users 0 2011-05-14 17:55 harve/comp_arch/Logisim
-rw-r--r-- harve/users 7492 2011-05-14 17:55 harve/comp_arch/Logisim/4-bit parity generator.circ
-rw-r--r-- harve/users 10237 2011-05-14 17:55 harve/comp_arch/Logisim/4-Bit Barrel Shift.circ
-rw-r--r-- harve/users 8486 2011-05-14 17:55 harve/comp_arch/Logisim/barrel_shifter.png
-rw-r--r-- harve/users 118337 2011-05-14 17:55 harve/comp_arch/Logisim/Bigger_Barrel_Shifter.circ
-rw-r--r-- harve/users 25292 2011-05-14 17:55 harve/comp_arch/Logisim/comparator1.gif
-rw-r--r-- harve/users 81 2011-05-14 17:55 harve/comp_arch/Logisim/Comparator_ROM
-rw-r--r-- harve/users 3802 2011-05-14 17:55 harve/comp_arch/Logisim/Cross-Over.circ
-rw-r--r-- harve/users 2630 2011-05-14 17:55 harve/comp_arch/Logisim/cross-over.png
-rw-r--r-- harve/users 5698 2011-05-14 17:55 harve/comp_arch/Logisim/Diode ROM Comparator.circ
-rw-r--r-- harve/users 6893 2011-05-14 17:55 harve/comp_arch/Logisim/Diode_ROM_Comparator.png
-rw-r--r-- harve/users 30207 2011-05-14 17:55 harve/comp_arch/Logisim/Discete_Comparator.circ
-rw-r--r-- harve/users 45620 2011-05-14 17:55 harve/comp_arch/Logisim/Discreet_Barrel_Shifter.circ
-rw-r--r-- harve/users 149693 2011-05-14 17:55 harve/comp_arch/Logisim/fig424.jpg
-rw-r--r-- harve/users 6963594 2011-05-14 17:56 harve/comp_arch/Logisim/logisim-win-2.7.1.exe
-rw-r--r-- harve/users 7333 2011-05-14 17:55 harve/comp_arch/Logisim/parity.gif
-rw-r--r-- harve/users 6320 2011-05-14 17:55 harve/comp_arch/Logisim/Sub Comparator.circ
-rw-r--r-- harve/users 4748 2011-05-14 17:55 harve/comp_arch/Logisim/Sub_Comparator.png
-rw-r--r-- harve/users 4287 2011-05-14 17:55 harve/comp_arch/Logisim/Circuit A.png
-rw-r--r-- harve/users 3317 2011-05-14 17:55 harve/comp_arch/Logisim/encoder.png
-rw-r--r-- harve/users 5182 2011-05-14 17:55 harve/comp_arch/Logisim/parity2.png
-rw-r--r-- harve/users 4791 2011-05-14 17:55 harve/comp_arch/Logisim/parity3.png
-rw-r--r-- harve/users 16633 2011-05-14 17:55 harve/comp_arch/Logisim/Parity Generator.png
-rw-r--r-- harve/users 811 2011-05-14 17:55 harve/comp_arch/Logisim/XNOR.png
drwxr-xr-x harve/users 0 2011-05-14 17:56 harve/comp_arch/MARS
-rw-r--r-- harve/users 3124936 2011-05-14 17:56 harve/comp_arch/MARS/Mars_4_1.jar
drwxr-xr-x harve/users 0 2011-05-14 17:56 harve/comp_arch/MARS/Program1
-rw-r--r-- harve/users 7654 2011-05-14 17:56 harve/comp_arch/MARS/Program1/fibonacci.s
-rw-r--r-- harve/users 14130 2011-05-14 17:56 harve/comp_arch/MARS/Program1/listing.lst
-rw-r--r-- harve/users 23483 2011-05-14 17:56 harve/comp_arch/MARS/Program1/listing.pdf
-rw-r--r-- harve/users 2543 2011-05-14 17:56 harve/comp_arch/MARS/Program1/one.html
-rw-r--r-- harve/users 11397 2011-05-14 17:56 harve/comp_arch/MARS/Program1/output.pdf
-rw-r--r-- harve/users 2242 2011-05-14 17:56 harve/comp_arch/MARS/Program1/output.txt
-rw-r--r-- harve/users 5617 2011-05-14 17:56 harve/comp_arch/MARS/Program1/Program1.tgz
-rw-r--r-- harve/users 18651 2011-05-14 17:56 harve/comp_arch/MARS/Program1/source_code.pdf
drwxr-xr-x harve/users 0 2011-05-14 17:56 harve/comp_arch/MARS/Program2
-rw-r--r-- harve/users 12975 2011-05-14 17:56 harve/comp_arch/MARS/Program2/birthday.asm
-rw-r--r-- harve/users 14293 2011-05-14 17:56 harve/comp_arch/MARS/Program2/birthday.script
-rw-r--r-- harve/users 29051 2011-05-14 17:56 harve/comp_arch/MARS/Program2/Birthday_asm.docx
-rw-r--r-- harve/users 44504 2011-05-14 17:56 harve/comp_arch/MARS/Program2/Birthday_asm.pdf
-rw-r--r-- harve/users 16653 2011-05-14 17:56 harve/comp_arch/MARS/Program2/Birthday_Script.docx
-rw-r--r-- harve/users 48137 2011-05-14 17:56 harve/comp_arch/MARS/Program2/Birthday_Script.pdf
-rw-r--r-- harve/users 87114 2011-05-14 17:56 harve/comp_arch/MARS/Program2/mccabe_program2.tgz
-rw-r--r-- harve/users 2734 2011-05-14 17:56 harve/comp_arch/MARS/Program2/two.html
drwxr-xr-x harve/users 0 2011-05-14 17:56 harve/comp_arch/MARS/Program3
-rw-r--r-- harve/users 15989 2011-05-14 17:56 harve/comp_arch/MARS/Program3/p3.asm
-rw-r--r-- harve/users 32515 2011-05-14 17:56 harve/comp_arch/MARS/Program3/Program3.docx
-rw-r--r-- harve/users 66517 2011-05-14 17:56 harve/comp_arch/MARS/Program3/Program3.pdf
-rw-r--r-- harve/users 1500 2011-05-14 17:56 harve/comp_arch/MARS/Program3/three.html
drwxr-xr-x harve/users 0 2011-05-14 17:56 harve/comp_arch/MARS/Program4
-rw-r--r-- harve/users 3047 2011-05-14 17:56 harve/comp_arch/MARS/Program4/four.html
-rw-r--r-- harve/users 14770 2011-05-14 17:56 harve/comp_arch/MARS/Program4/Program4.asm
-rw-r--r-- harve/users 17149 2011-05-14 17:56 harve/comp_arch/MARS/Program4/p4_working.asm
-rw-r--r-- harve/users 1741 2011-05-14 17:56 harve/comp_arch/MARS/Program4/permute.cpp
-rw-r--r-- harve/users 582611 2011-05-14 17:56 harve/comp_arch/MARS/Program4/permute.exe
-rw-r--r-- harve/users 21065 2011-05-14 17:56 harve/comp_arch/MARS/Program4/Program4.docx
-rw-r--r-- harve/users 133434 2011-05-14 17:56 harve/comp_arch/MARS/Program4/Program4.pdf

root@alpha:~/tape2173# tar -xvf /dev/st0

harve/comp_arch/Logisim/4-bit parity generator.circ
harve/comp_arch/Logisim/4-Bit Barrel Shift.circ
harve/comp_arch/Logisim/Diode ROM Comparator.circ
harve/comp_arch/Logisim/Sub Comparator.circ
harve/comp_arch/Logisim/Circuit A.png
harve/comp_arch/Logisim/Parity Generator.png

root@alpha:~/tape2173# exit

Script done on Sat 13 May 2017 02:14:51 PM EDT

Retrochallenge 2017/04 Final Report

The TapeStore server has been completed and most planned functionality has been achieved.  In total, more than 80 videotapes of various types were digitized and stored in the server, along with several hundred audio cassettes, open-reel tapes, and 9-track magnetic tapes.  The following is a summary of the machine’s capabilities and content:

  1. Central Processing Unit –AMD Athlon64 x2
  2. RAM — 3 GB
  3. System Disk — 384 GB
  4. TapeStore Disk — 2 TB (75% full)
  5. Operating System (Temp until open-source drivers for all hardware can be located):  Windows VISTA SP2
  6. Special Interface Hardware:  Hauppage WinTV HVR-1255 (Analog Video Input), IEEE-1394 x 4 (Digital Video Input), Adaptec SCSI PCI Card (9-track data tape), Creative Sound-Blaster X-FI HD USB Audio Interface, Four-Port EIA RS-232C, Custom Commodore Cassette Interface.  Extron VSC 500 Scan Converter (Composite Video Output), QSI Video Sync Generator / Color Bar Generator, Micro-Time Frame-Sync and Time-Base Corrector, General Electric SVHS Video Cassette Recorder, Sony DVD-R Recorder, Ampex VPR-80 Videotape Recorder, Ampex TBC-40 Time-Base Corrector, Sony HandiCam.
  7. Software:  Hauppage WinTV (analog video input), VLC Media Player (video output), Handbrake (Video Format Conversion), FileZilla FTP Server (Primary server software.)  Misc. Disk-imaging utilities.

Tasks to be accomplished include (1) Creating some logical (and workable) system of organization for all these (rather large) files on disk, (2) Creating a comprehensive index of the contents, (3) Improving control of peripheral devices (current operating of VCR / VTR / DVD / and audio devices is generally manual.)  (4) Getting the Commodore Datasette Interface to work reliably, (5) Getting the RS-232C command-line functionality to work.

It’s been fun, but I’m running out of time.  Wishing the best to everyone else involved in the Retrochallenge!






Retrochallenge Day 21 — 75% Complete with Little Progress

The database called TapeStore is largely completed, built up from hundreds of audio and video recordings and comprising just under a terabyte of raw information.  I’ve worked a bit on getting everything organized, but in keeping with the Retrochallenge Theme I need to be able to locate and recall that information in a manner usable on a vintage computer system.  Sending streaming video to a Commodore VIC-20 over a serial link is probably impractical, given the low data rate and tiny memory, but can actually be accomplished if we treat the TapeStore server as a peripheral and transmit our program content using standard video and audio cabling to a second monitor connected directly to the TapeStore System.

What I envision at this point is sitting at the console of my VIC-20 (or any other 8-bit antique) and requesting a particular audio or television program from the TapeStore server.  TapeStore checks its table of contents, and if the program is available begins playback over a standard video and audio link.  It takes an extra monitor and some ancillary equipment but what we have is a version of YouTube circa 1984.

Right now, the plan is to move the TapeStore drives to a Linux system that supports serial terminals and allows shell access via a terminal program running on the vintage PC.  Server-side programming accepts the program request and begins playback using dedicated video and audio links to a second monitor located adjacent to the 8-bit console.  If I can figure out how to generate a plain-old NTSC video signal on TapeStore, the server software should be a small matter of programming.  In the end, all we have is a high-capacity and overly complicated VCR that runs under programmed control, but it’s a neat hack and worthy of the Retrochallenge.

I have nine days to implement this.  See you soon!


Day 13 — Compact Cassettes Getting Loaded

The number of different media types here is overwhelming… My project started with the Digital-8 Videotapes because of the ease in converting the digital video stream on the tape into a digital stream on disk. Likewise, the 9-track tapes were easily copied from tape to disk-images using the Linux DD command-line utility. Making sense of the data might take a bit longer in some cases, but most of the 9-tracks contained TARballs from earlier incarnations of the Unix Operating System, so decoding them won’t present much of a challenge.

2017-04-13-143801 2017-04-13-143810 2017-04-13-143816

I’ve now moved back into conventional analog media — in this case, audio cassette recordings.  I’m using Audacity to record them to disk and generate MP3 files, but the sheer number of audio cassettes (and a few reel-to-reel tapes that I’ll convert with the same setup is pretty daunting.  I’ll start with this “small batch” of 100 tapes or so, and work my way through the library given time.  I probably won’t get through everything in time for the retrochallenge deadline.


Retrochallenge Day #4

The TapeStore project is moving along slowly. I’ve managed to digitize and upload the first 22 8mm tapes from the Sony Digital Handycam and fill about half of my first 500 GB Hard Drive.  While uploading the tapes, I’ve been taking notes and plan on starting my index database soon.

The next phase of the project will be to dig out the Ampex VPR-80 and Time-Base Corrector so that I can digitize and upload the dozen or so 1″ C-Format tapes in the collection. Some of these are edited copies of stuff that was sourced on the Digital-8, so you’ll see a certain degree of duplication.  Moving several hundred pounds of vintage video gear is a project in-and-of itself and I plan on filming the operation. Stay tuned for more video updates from Paleoferrosaurus.


Digital – 8mm Videotape (Sony Handycam)

Scanning the first few tapes is going well, but it seems I’ve vastly under-rated the amount of online storage I’m going to need to pull off the entire TapeStore Database.  I started with a 500 GB media drive on the video acquisition system in addition to the “native” 140 GB Windows volume.  This is on a “vintage” PC from 2007 (at 10 years, it actually meets the criteria for the Retrochallenge!) running Windows VISTA.  While scanning the 8mm videotapes, I’ve been looking at other media; the VHS tapes are relatively low-res so I’m not worried about the filesize, but even with compression I’m going to be hard-pressed to store all the Ampex videotapes on this system.  I haven’t even gotten as far as the 9-track stuff yet.


This screen-shot shows the directory listing for the first 16 tape cassettes.  Yes, I can count.  Tape 13 broke while playing, necessitating another file (AV8MM0014) to store the remainder of the tape.  I have another broken tape that’s going to need some TLC before I can scan it, so the day isn’t over yet!


This version of Windows doesn’t give you much of a preview while importing video, so an outboard monitor makes it easier to see what’s actually going onto the hard drive.  I’m also taking notes on the content of each tape while it’s uploading for the purpose of building an index to the content of each tape while building the TapeStore database.

Each file created from an individual tape gets a simple, systematic “name” describing the type of media stored therein.  This series is named as follows:

  • AV — For “Audiovisual” media
  • 8mm — for the source format
  • A unique sequence number

Thus, the first file in this series was AV8MM0001 and so on, leading up to the current tape, AV8MM0017.  Each tape has a general title, such as “Aurora Band Concert”, a series of named scenes, and notes based on content keywords.  I’m not sure yet how I’ll organize the rest of the database, but I’m hoping to come up with something that can link related documents in the grand scheme of things — I might want to find both the original “un-cut” footage and edited copies of a tape, for instance.

It might seem redundant when viewed in the context of a relational database, but I hope to keep much of the meta-data “built-in” to the directory structure.

Retrochallenge 2017/04

Greetings, fellow retronauts!

My project this time is called “Tapestore.”  It’s a small database containing large objects like operating systems, system images, video tapes, audio recordings, and photographs that are stored on a variety of media ranging from punch cards to 9-track tapes to various obsolete disk storage systems.  My goal is to put all this digital detritus into a form that can be stored and selectively retrieved on modern large-capacity hard drives but still be accessible to both archaic computer systems and modern emulators.

Vintage gear supported by this endeavor will include the Digital Equipment Corp. PDP-11, the Apple II+, Apple Macintosh, and Vintage PeeCee Type Equipment.  Work product will include source code, blog entries, and hopefully some video.

Recently, I was asked to provide a machine-readable copy of some documentation I wrote back in the late 1980’s.  The document was a set of programming specifications and a list of tone frequencies for the Zetron Model 25 encoder used at West County Fire Control in Girard, PA.  I knew right where it was and found it within a few minutes — wonderfully intact after all this time on a ProDOS data disk for the Apple IIe.  Sadly, I couldn’t find any quick methods for getting that data from a vintage Apple over to the Linux laptop for editing and transmission.  Yes, I have an Apple II emulator on the Linux box, but very little of the data I kept on floppy disks back in the day ever made it to the “new” computer.  Based on how you count the generations, I’ve had at least four generations of Apple computer, a few PeeCees, and three generations of Unix / Linux since that time.

The rest of the library isn’t in much better shape; there are punched paper tapes, C-Format Videotapes, Kodachrome slides, vinyl records, and DVD’s scattered all over the place and a host of different machines required to access the data.  What I really need to do is consolidate my stuff into a set of sustainable, current media formats that I can quickly locate and make use of without digging out the vintage Apple II or the Ampex VPR-80 and associated equipment.  Hopefully, TapeStore will be the answer.

The plan right now is to find some way of getting all this “stuff” into a format that can be stored on a current PC for safe, long-term storage, and ease of access.

In terms of video alone, I’m looking at several Terabytes of information, so while the number of entries in a “card catalog” might not be excessive, the actual content may prove to be rather enormous.  The first set of videotapes to digitize will be my Digital-8 “Home Movies” shot over the last 15 years.

These tapes were once the cutting-edge in home video production, with relatively high resolution NTSC video and good quality stereo sound.  The camera was also “computer” friendly with both USB and Firewire output as well as S-VHS and Composite Video connectors.


The chief disadvantage to this camera is its age and the likelihood that a malfunction will render the tapes useless since I have no other device that can read the tapes.  The battery is also starting to show the limits of the “Infolithium” system favored by Sony in the first few years of the 21st century.

All told, I have perhaps thirty tapes in this format representing perhaps 25 hours of usable video.  Getting the video online isn’t much of a challenge, since the Firewire connection allows for rapid hi-quality transfer of raw data from the camera without need for extensive processing.  Storing the camera data in “AVI” format (Audio – Video Interleave) is relatively lossless but not very space efficient.   At around 13 GB per hour, I’m looking at around 325 GB for my Digital-8 Home Videos.


About Paleoferrosaurus

Context is everything.  For the few people on Earth that actually read this drivel, most will not know me personally.  We probably share some common interests that led you here, but sometimes a little bit of background information is helpful in interpreting what you find.

My name is Micheal Harve McCabe.  I’m presently 49 years old and live in northwestern Pennsylvania in the United States of America.  I’m married. I have three adult children.  I’m a graduate of Edinboro University of Pennsylvania.  If population demographics are an interest of yours, I’m a fat, middle-aged, white male. I’m not religious, and the current political climate of the United States disgusts me.

I am presently employed by two public-safety agencies in Erie County:  The West County Paramedic Association where I serve as an IT specialist and part-time paramedic; and the Central Erie County Paramedic Association where I serve as a full-time paramedic and general purpose technical wizard — involved in the care and management of computers, radio communications, and biomedical electronics.

I am a hacker and a tinkerer.  I write a lot of code for embedded devices that find use in communications equipment and medical devices.  Most of that stuff is pretty boring. The stuff that isn’t boring (from my perspective) are the “vintage” and “classic” computers that I tinker with and (occasionally) find useful applications for.

My hobbies include amateur radio (call sign: KB3NJY), model rocketry, firefighting, local history, and cellular biology.  I enjoy reading and writing both fiction and non-fiction.  I am sometimes employed as a teacher at the post-secondary level where I’ve taught classes as diverse as Medical Terminology, Human Anatomy, Medical Laboratory Practices, and Health Information Technology.

The content of this blog and associated web pages will reflect, to a greater or lesser extent, the total scope of my interests.  You will find articles on topics ranging from pre-hospital medicine to retrocomputing to railroad history and anthropology.  While I’m an expert in none of these fields, I tend to write whatever crosses my mind in a given moment.  As always, take everything with a grain of salt and consider the source!