Old Computers &
CalculatorsOld Computers &
CalculatorsComplete and working, with software and manuals where necessary:
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Slide Rule - an almost forgotten type of calculator, though it was widely used for many decades. I believe this example is from around 1940 and gives 3 or 4 digit accuracy on multiplication and division, square roots, etc. Knowing how to use a slide rule is a skill which is rapidly being lost. It works on the same principle as Logarithm tables - another skill which will soon be forgotten. |
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Olivetti Summa Prima 20 mechanical adding machine. Made in Italy, around 1960, based on similar machines from the 50s. The keyboard includes special keys for "10" and "11", for working in pounds, shillings and old pence. Prints the answers on to a small roll of paper using black ink for addition and red ink for subtraction. Works, though it needs a new ink ribbon. |
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Sinclair Cambridge Calculator. This was launched as a build-it-yourself kit for less than £30 in 1973, making it one of the first affordable pocket calculators in the world. It is a very compact four function calculator - just 11 x 5 centimetres (4.5 x 2 inches). About half the space is taken up by four AAA type batteries. The display uses tiny seven-segment red LEDs. Assembly required a fair amount of skill - two ICs and about 20 passive components had to be soldered into a pretty small space! |
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CBM 8032 with
32K of RAM, cassette tape, dual floppy disk unit, and
BASIC in ROM (c.1980). This was a
development of the popular Commodore PET range, which
pioneered home computing in the late 1970s, and uses the
same 6502 processor. The 8050 disk unit takes up to two
5.25 inch floppy disks, each holding approximately 500
KB. Interestingly, the disk controller uses two
6502 processors, making it twice as powerful as the
computer... This picture shows the external cassette tape drive at the right. The disk drives cannot be seen. |
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Apricot PC with twin 3.5 inch floppy disks, running MS-DOS 2.0 (1983). This excellent machine was years ahead of its time. As well as the high-resolution monochrome monitor, the keyboard includes a liquid-crystal "Microscreen" to provide programmable labels for the six function keys, and it also worked as a stand-alone calculator. Fitted with 256K RAM, the Apricot was supplied with Microsoft interpreted BASIC and SuperCalc spreadsheet on floppies, along with numerous utilities including a font editor for creating your own screen fonts. Other software available included Pascal, Fortran and Cobol compilers. Apricot Computers - based in the UK - adopted the compact and robust 3.5 inch floppy disk several years before IBM. |
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Hewlett-Packard 150
with Touch Screen and twin 3.5 inch floppy disks, running
customised MS-DOS 2.0 (c.1984). HP
included a special front-end program for MS-DOS to make
use of the Touch-screen for file management etc. The
touch-screen uses an array of infra-red light beams
across the surface of the screen. Unlike most PCs, the
8086-based motherboard is inside the monitor, and only
the disk drives are in the base unit. These are connected
using an HPIB cable, also known as GPIB or IEEE-488. There is also a recess in the top of the monitor where a small dot-matrix printer can be installed. |
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Apricot F1 with 10 MB hard disk & colour monitor, running MS-DOS 2.11 (1985). Both keyboard and trackerball-style mouse are wireless, using infra-red links to the system unit - another Apricot innovation which was years ahead of the competition. The system unit was exceptionally small for its time - about the size and shape of a shoe box - but it still managed to hold a hard disk drive and an expansion slot for a modem or other card. As well as MS-DOS and Microsoft BASIC, this also shipped with GEM Desktop - an early attempt at a mouse-driven graphical user interface that pre-dates Microsoft Windows. |
Parts of:
IBM 7040 Mainframe. One of the first generation of transistorised computers, this model was launched in 1963. It was built from thousands of discrete transistors, and used more than 1,000,000 tiny magnetic cores for the main memory (32K words of 36 bits each). It was originally installed in Switzerland, and later used in Manchester until 1982. Software available included some of the very first compilers for COBOL and FORTRAN from the early 1960s. The operating system - IBSYS - ran one program at a time. The full system filled a room and required a 3-phase industrial power supply
The 7040 Central processor had floating-point hardware, 3 index registers and a complex instruction set with more than 100 instructions, including hardware multiply and divide. The instruction set was compatible with the faster 7090 system, which NASA used to control the early space missions. Some features of the Fortran language, which is still being used in scientific applications, relate directly to the instruction set of the 7000 series CPUs.
This is part of the CPU control panel, showing the power controls, and some of the lights which indicate the contents of CPU registers.
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One of the logic cards from the CPU. The complete processor contained hundreds of circuit boards like this, plugged into racks the size of wardrobes. The circuits are built from discrete transistors, resistors, diodes and capacitors, and used a variety of supply voltages, both negative and positive. |
| Using this mid-70s technology, the 128 MB RAM found in a typical home PC today would require about 1,400,000 chips covering nearly 11,000 large circuit boards. And that's just the memory... |
Vintage Computer Links
For a summary of the history of computing, try this Timeline.
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