Index: en/computer/early-computers.shtm
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Schoppe & Faeser: LGP-21 (General Precision)
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From left to right: magnetic tape drive, 1. LGP-21, Tally paper-tape-reader and punch, 2. Tally reader, two additional hard drives, 2. LGP-21, Flexowriter
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The LPG21 computer by General Precision was released and licensed in the
+USA in 1962. Paying royalities, the german company "Schoppe & Faser"
+copied this computer with a new frontend design, calling it "EUROCOMP"
+(1964).
+ It's a very small mainframe, advertised as the "first
+full-capability computer priced from $ 16,250". Of course this price was
+only offered for the bare CPU. Including the minimal equipment
+(flexowriter, tape reader and puncher) the overall price was about $ 30,000.
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The external memory of the LGP-21 are perforated papertapes, which are scanned mechanically of the Tally-tape reader. The magnetic tape drive and other external drives were added in the late 60s.
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+The (rotating) disc (with fixed heads) is used as storage and clock
+generator. Our installation, as shown above, features a lot of
+periphery: A magnetic tape station (1/4" tapes), paper tape
+reader/puncher, an additional hard disc and a flexowriter (printer and
+manual tape puncher for data/programs).
+Once again, the reperation will be a challenge. More information will be
+disclosed later.
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Mini-Computers
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Today's kids think of the latest mobile devices when talking about "mini computers".
In contrast, in the 1960s and the early 70s, a computer was always huge (like our
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Edson de Castro was responsible for product management at DEC and was intent
+on developing a 16-bit computer with a processor that would fit on a single
+printed circuit board. But Ken Olson, the founder of DEC, wasn't
+supportive. So de Castro left DEC in 1968 together with three other
+hardware engineers to found his own company in a vacant barber's shop:
+Data General Corporation (Massachusetts, USA).
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+Already in 1969 the first 16-bit computer in the "NOVA" series was ready
+for the market. Thanks to the simpler production method (no wire wrapping,
+only two boards + memory boards etc.) the basic version was quite inexpensive
+at $4000. However, this basic model alone wasn't really that useful, and
+after extending the computer the total price was substantially higher.
+The Nova computer was advertised as "the best small computer in the world".
+At this time, DEC was still building the PDP-8/I and the PDP-12, which
+required lots of very small flip-chip-modules.
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+The successor model (available in 1973), the NOVA 2, was simplified even
+further, and the increased chip density made it possible to have the whole
+processor together with the control logic for slow peripheral devices
+(teletype, paper tape puncher and reader) one single board. Our Nova is a
+NOVA 2/10 model with slots for 10 boards, and therefore enough space for
+quite a few device controllers and memory extensions.
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+From today's perspective, the rather huge boards (15x15 inch,
+nicknamed "circuit graveyards in baking tray size") do have disadvantages:
+any kind of repair is very difficult, because it is not possible to pin down
+a malfunction by exchanging small boards.
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+The NOVA shown in the picture is from a university. It is equipped with
+two harddisk drives, one twin floppy drive (8" disks!), one teletype,
+one high-speed paper tape punch reader and one punch card reader (not in
+the picture). Later on a terminal was added, which extended the computer
+to a comfortably usable system.
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+The details are better visible in a larger photo:
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+Hardware configuration, from top to bottom:
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+- Paper tape punch reader (mostly used for testing programs included with
+ every delivered system)
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- Twin disk drive for 8-inch floppy disks, Model 6032
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- CPU with core memory, 32 KB, access time 0.8 us
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- Two hard-disk drives with removable cartridges, Series 30. Capacity
+ 1.200.000 16-bit words, or 2.4 MB.
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- Disk Cartridge System 4047, necessary to connect the second disk
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- Terminal "DASHER 1", Model 6052 by Data General, on the right hand side
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