If you have responsibility for a collection of chemicals, or a complete chemical storeroom, you should be keeping an accurate inventory which should be updated annually. In doing your inventory you will want to estimate how much material you have left in stock so that you can make an informed decision about future purchases. I keep a collection of plastic chemical storage bottles on-hand for just this occasion. The collection includes the most popular sizes that my suppliers use to distribute their wares. When the contents of a bottle have been consumed I will clean it throughly, mark through the information on the label and save it in a box. When inventory time comes around I use the empty bottles to tare an electronic balance and then place a matching bottle from my storeroom shelves on the balance and voila, a quite accurate measure of how much material remains on my storeroom shelf. Of course this only works for solids; unless you want to do some calculations involving density. For liquids I calibrate a bottle by incrementally filling it with water and making marks on the exterior for each increment; 100 mL or 250 mL work nicely depending on the capacity of the bottle. I suggest you use bottles that have contained materials of low intrinsic hazard.

*or any other chemical

I started on computers at a time when most people had never actually seen a computer in-person and the concept of a “personal computer” was not as laughable as 5 or 10 years before. I was fortunate to start on an IBM 1130 system at my high school which allowed some “hands-on” experience. Students in the computer courses had fairly generous access to the system which was all contained in the same room with the keypunch machines. Several friends and I had established a friendship with the computer operator which afforded us after school access for independent projects (mine was a heuristic tic-tac-toe program written in Fortran and played through the system console).

I moved in the middle of my junior year to a school that did not have an on-site system and thus was introduced to the novelties of TTY, Basic and punched paper tape storage. We also had a couple of Monroe card-programmable calculators–they were as big as a typewriter and used “pixie” tubes. That transition marked the end of my system console days; for more than a decade afterward I would be forced to submit my jobs through remote card readers or 3270 terminals. I continued to work on computers as card-decks were replaced by TSO and CMS until the early 1980s.

At the begining of the 80s  I purchased my first personal computer. I had known of personal computers since the first kits were available through ads in Popular Electronics. And I had followed the progress through that same magazine. I started purchasing Byte magazine issues from its first release. But I waited for a while and eventually purchased a Radio Shack TRS-80 Model III. Initially it only had the TRSDOS operating system and the BASIC interpreter. Over time I switched to DOSPLUS, and added an assembler, a COBOL compiler (I did it for another programmer–that’s my story and I’m sticking to it), and other utilities. I poured over all the “mystery” books, studying line after line of decompiled code and the OS internals. It was a blast! I still have that system, and I am going to have to fire it up again someday soon. [I couldn’t resist; I got it out and turned it on–it worked! Played ZORK for a little bit. Ahhh, nostalgia.]

I had been aware of Apple computer but really didn’t see the need for color; after all I was a “serious” programmer not a game jockey. But then I discovered Lisa. Of course I am referring to Apple’s first GUI system. It was and still is amazing. I had an opportunity to work on one at my job, but only occasionally. Most of my time was spent on a local university mainframe, an in-house data-entry system, a couple of IBM Displaywriter systems, an IBM PC or two,  and a couple of Kaypro computers that I was interfacing to some lab equipment. I learned how to program in Forth for the interfacing project and I still think Forth is a great interpreted language. Anyway, the Apple Lisa birthed in me a love for GUI which would eventually fixate on Macintosh.

I purchased a Macintosh 512K system in 1985 and haven’t purchased another brand of computer for my main use since. That was five Macintoshes ago (512K, MacPlus, Mac II, Quadra 630, iMac for my wife, PowerBook, MacBook) and I have never regretted going the way of the Mac. I collect computers now and have a fair selection including some 8080- and Z80-based systems besides the TRS systems, all my Mac’s except the MacPlus which I sold to finance the Mac II purchase, and a couple of other Mac’s I picked up to add to my collection. I also have one analog computer by Heathkit.

In addition to the ready-to-run systems, I also have an interest in single-board and microcontroller systems. Right now I am playing with a couple of Arduino Diecimlia boards and a Basic Stamp system at the heart of a robotic motion platform. I might post more about them at another time. I might also post about all the languages I have learned along the way. Won’t that be exciting.

Happy New Year!