In October 1969, my engineering school acquired (was given?) a IBM-1620
It was the first computer using transistors and, you’re ready, it was a BCD machine (Binary Coded Decimal)!
Let me explain what it is: If you look at the table below, you can see that it takes a lot more bits in BCD than it does in binary.
Decimal BCD Binary Hex
So the largest number you can use in a 16-bit BCD machine is
1001 1001 1001 1001 i.e. decimal 999.
In a binary machine with the same number of bits:
1111 1111 1111 1111 i.e. decimal 65,535 is the maximum number.
In hex, which is only a translation of the binary value into a more compact notation: FFFF
You can imagine how much computational power was being lost using BCD-numbers.
It was fun, though, because it had a Fortran II compiler which allowed us, “almost engineer” to acquire some computer skills.
I started my Ph.D. program in oct 1970. Soon, the need for a computer became apparent. After a lot arguments with the forces that were (they wanted me to buy a Multi-8, an already obsolete 8-bit computer from the French company Intertechnique), I succeeded in getting Digital Equipment PDP-8/e: $5,000, 4k 12-bit memory, teletype. You had to enter all the programs through the tape reader (10 char/s) on the teletype. Later on, I got DECtape (small magnetic tapes) with an operating system, OS8. That made all the difference.
1973 Nicolet 1080
When I started working for Cameca, I was in charge of all the programs for the new NMR spectrometer using Fourier Transform. Although there was an operating system, all the programs had to be written in Assembly Language. At the time, the only computer capable of performing Fourier Transform with any accuracy was the Nicolet 1080/BNC-12: it was a 20-bit computer with blocks of 16K core memory, with its own display and a 10 Mbyte removable disk.
1981 Nicolet 1280
At Harvard, I got to use the successor of the 1080, the Nicolet 1280: 800 ns cycle time (1.25 MHz clock – it’s a M not a G!). Also in assembly language, but now it had a Basic interpreter which allowed fast sophisticated programming. This is with this computer that I wrote the music software (See Pipe Organ).
1984 VAX 11/750 - CDA MSP-3000
When I arrived at the Radiology Department at the University of Texas Medical School in Houston (UTMS-H), I had to create my own lab. Not only did I have to hire people, but also order equipment. The Cardiology Department was already equipped with a VAX-780. So ordering a VAX-750 was not a problem. Since we were doing MR Imaging, we added an Array Processor: the CDA MSP-3000. Everything was programmed in Fortran IV (no more assembly language).
1985 Jan Macintosh 512k
The Macintosh 512k was introduced in Sep 1984. At that time, Apple was looking for developers to create new applications for the new computer. The retail price was $2,795. Becoming a developer was quite simple: you would send a $1,600 check to Apple telling them you wanted to be a developer. And voilà: you would get it with MacPaint and MacWrite and that was it…
1985 Nov VAX 11/730
In October 1985, there was an ad in The Houston Chronicle regarding a University in Texas selling a VAX-730 with a LP37 Line Printer, LA-36 DECwriter, 10 MB RL02 removable disk, 121 MB RA80 Disk Drive, TU45 Tape System and a VT-100. Make offer at that phone number… Knowing what I knew about DEC equipment, I estimated the whole thing at $50,000.
So, I called and found out that the complete system had been given to them (Central Texas College) by Martin Marietta, that there was no software with it (I did not care, I had all the software on the VAX 11/750 and it was compatible) and that they had not been able to restart it. I made an offer of $5,000 and left my phone number. Thirty minutes late, I was the owner of my new personal computer.
With Bill Brey, one of my co-worker, we took an afternoon off and went to Killeen in a U-Haul. We met the Dean (?) and the CFO (?). They accepted the certified check and told us the equipment was not on the premises. We were kind of surprised and we followed them to a … TV Store in some shopping center ! We loaded the equipment, came back and hauled it to the second floor of 6006 Bellaire Blvd where the Tecmag suite was, back then.
They were right: the system would not boot. At that time, DEC equipment was so popular and their field service so expensive that here was a second market for DEC maintenance. I contacted one of them who diagnosed that the hard disk was dead: the timing track had been erased. Martin Marietta had passed the disk through a degausser ! For $2,000 I got a new disk and was able to restart the whole thing. Everything worked and here I was at the head of a company that did not have any employee but had a VAX 11/730.
Since 1997 PC's & Mac's
At home, we have 12 PC’s (1 for Lauren, 1 for me, 1 for the organ, 1 for the trains, 1 for the museum, 1 portable, 1 backup for the organ, 1 unused and 4 legacy), 1 Mac and 2 iPad’s. So far.