Re: [oldcalculatorforum] Digest for oldcalculatorforum@googlegroups.com - 1 update in 1 topic

[Diestelkamp]

Hello Rick,

thank you very much for this long explanations!
Very interesting and better than a book!

One more "display":
Conon Pocketronic.
Stripes of paper, printed and visible like "normal" Display!
At the moment I'm repairing my Pocketronics: a lot of akkumulators.
The paper stripes are very old, yes, more than 50 years, and are nearly
blind.
I do have some stored at -18 Celsius and hope they are in better condition!

All the best from Bavaria,
Friedrich


Am 19.03.2026 um 08:37 schrieb oldcalcul...@googlegroups.com:
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> Group: oldcalcul...@googlegroups.com
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> - Sanyo ICC-82D - Charger or Mods [1 Update]
> http://groups.google.com/group/oldcalculatorforum/t/893eddb34ba37a99
>
>
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> Topic: Sanyo ICC-82D - Charger or Mods
> Url: http://groups.google.com/group/oldcalculatorforum/t/893eddb34ba37a99
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> ---------- 1 of 1 ----------
> From: Rick B <rben...@gmail.com>
> Date: Mar 18 07:05PM -0700
> Url: http://groups.google.com/group/oldcalculatorforum/msg/7f69f567cda1
>
> Greetings, Owen and all,
>
> I don't know if I would say it is accurate to call it an evolution in the
> pure sense of the word, because generally there are various stages in an
> evolution, and in the case of Nixie tubes to Gas Discharge seven-segment
> tubes, there were no intermediate types of tubes. Both display
> technologies are cold-cathode (e.g., no heater element to give off
> electrons like in an old-style vacuum-tube used in TVs and radios in their
> early days) devices with similar gas chemistries inside the tubes, and
> operate on roughly the same voltage, but that is where the similarities
> end.
>
> Vacuum fluorescent display tubes were a completely different technology.
> They had a heater element in the tube, like an old vacuum tube, which was a
> source of electrons. The cathodes were phosphor-coated segments in the
> seven-segment (and sometimes more) layout, and when a positive voltage was
> applied to a segment cathode, the electrons from the heater element would
> be attracted to the cathode, hitting the phosphor, making it glow in a
> bright, generally light-blue color. Like the segmented gas-discharge
> tubes, lighting different patterns of the segments resulted in a reasonable
> representation of a numeral.
>
> I'd say that the VF tubes were not an evolution of the Nixie tube, at least
> from a technology standpoint.
>
> I would say, though, that both display tube technologies were developed out
> of a desire to create an easier to manufacture and thus lower-cost display
> than Nixie tubes, which were pretty fussy to build. With all of the digit
> cathodes stacked up on top of each other with very little space between
> them, and an anode grid placed in front of the stack of digit-shaped
> cathodes, all packed inside a glass envelope with a fairly tightly
> controlled amount of neon and other gasses pumped in at a slight amount of
> pressure inside the tube, and sealed such that the gas would not leak out
> of the tube through the holes in the bottom of the tube where the wires
> came out. Nixie tubes were considerably higher cost display technology
> than the gas-discharge and vacuum-fluorescent display tubes that succeeded
> them, especially once these later technologies that integrated multiple
> digits inside a single glass envelope or panel.
>
> Another type of gas-discharge display technology that came after the
> individual gas-discharge display tubes had been developed, eventually
> displacing individual tubes, was Burroughs' Panaplex planar gas-discharge
> display technology. This technology was as the Nixie tube was to the
> Pandicon tube...where rather than having separate tubes for each digit, all
> of the digits were combined into one package, though in this case, the
> package was planar (flat) as opposed to a glass envelope. This display was
> called the Burroughs Panaplex display. Panaplex technology used glass
> plates, one with a clear anodes, one for each digit, and another with clear
> cathodes printed on the glass in the shape of the segments that created the
> numerals, with the two plates separated by a small distance, and the space
> between them filled with the Neon gas mixture. This allowed quite a few
> digits to be combined into one flat display panel.
>
> A Japanese company whose name I can't recall at the moment created a
> similar planar gas-discharge display, but was different enough in design
> that it didn't violate Burroughs' patent on Panaplex. They called the
> display "Flattron". Rather than printing clear conductors on glass like
> Panaplex, the Flattron used a thin metal plate with the shape of the
> segments cut out of it for each digit, connected as the anodes. A flat
> ceramic base material with the segment shapes printed on it using a thin
> metal paste was positioned a short distance behind the anode plates, were
> the cathodes. The assembly was placed in a stamped metal tub, with the
> pins for the anodes and cathodes coming through glass-frit sealed holes in
> the back of the tub. Across the top of the tub, a pane of glass was sealed
> to the edges of the tub with some type of adhesive and seal. A small
> amount of gas similar to that used in a regular gas-discharge display tube
> was injected into the assembly. The glass pane provided a window for the
> viewer to see the display. When a given numeral segment cathode, along
> with a digit anode had sufficient electrical potential across them, the gas
> would glow in the shape of the segment showing through the segment-shaped
> cutouts in the digit anode.
>
> Both Panaplex and Flattron planar displays had all of the like numeral
> segments connected together inside the display panel, so that changing
> segment patterns applied as a potential (for a lit segment) or lack of
> potential(for a dark segment) were applied to all of the cathodes at the
> same time, but only the digit with the anode energized would have its
> segments glow, creating the pattern of a numeral. This scheme of
> connecting all of the cathodes together and only energizing the segments
> for each numeral momentarily, as well as energizing the anodes
> sequentially was called multiplexing, and dramatically reduced the
> complexity and component count of display coding and drive circuitry. For
> example, a Sharp Compet 20 calculator (fall, 1965), which did not use
> multiplexed display technology, had roughly 268 transistors in its display
> drive circuitry alone. The Sharp Compet 32, a later(mid-1967) machine
> that was Sharp's first calculator to use a multiplexed display scheme (with
> Nixie tubes), used roughly 37 transistors, and it had two more digits of
> capacity than the Compet 20!
>
> The number of soldered connections in a calculator was a very important
> design criteria for reliability. Reducing the number of soldered
> connections to components would increase reliability, as soldered
> connections were an opportunity for a bad solder-joint to cause a
> malfunction. Less solder joints meant less chance for a problem in
> production, and once in the customer's hands.
>
> Individual tube-type displays required n*12 soldered connections, with n
> being the number of digits in the display system. For example, a
> twelve-digit display would require 144 soldered connections to all of the
> tubes in the display. A planar-type display like the Panaplex only
> required n+8 soldered connections, with the same twelve-digit display
> requiring only 20 solder connections, significantly increasing
> reliability.
>
> The reduction of solder connections was one of the factors leading to the
> use of small-scale integrated circuits to replace discrete components, and
> later to the use of large-scale integrated circuits, both of which combined
> the equivalent of (early IC's) perhaps ten to fifty components on a single
> chip that might have fourteen to sixteen soldered connections compared to
> up to 100 or so connections for the same circuitry implemented with
> discrete components. Early LSI IC's contained hundreds to thousands of
> equivalent components on a single chip, with perhaps 28 to 40 solder
> connections per chip. While the benefits to the use of integrated
> circuits in calculators are obvious as far as the reduction in size, power
> requirement, cooling, and overall complexity, the reduction in the number
> of soldered connections through the use of multiplexing, display systems
> that embedded cathode connections in the display element itself, and the
> introduction of integrated circuits all contributed significantly to the
> reduction of the number of soldered connections to make a calculator,
> drastically increasing reliability and in most cases, longevity.
>
> In the case of vacuum-fluorescent display tubes, eventually the individual
> tubes for each digit were combined into a single glass envelope with
> multiple digits inside, again tying the cathodes all together and using
> multiplexing to drive the display In the end, planar multi-digit
> vacuum-fluorescent displays were developed, reducing the depth requirement
> of the display element. These planar type vacuum-fluorescent display
> devices are still used today, and found in things like microwave oven
> displays, displays for audio equipment, and office-oriented AC-powered
> desktop calculators where the readability of the display versus
> liquid-crystal displays is a concern, with VF tube displays being much more
> readable in office lighting conditions. There are even multi-color
> vacuum-fluorescent display panels, with different phosphor materials
> deposited on various cathodes to create colors such as red, orange, and
> green-blue, along with the usual light-blue color. Some vacuum-fluorescent
> display panels have a large number of individual dots of phosphor that are
> individually addressable (by rows and columns refreshed rapidly), such that
> simple monochrome graphics and arbitrary fonts and figures can be
> displayed. For a time before Liquid-crystal (LCD) flat panel displays were
> invented, a lot of research went into miniaturizing these dot-matrix
> vacuum-fluorescent display elements. The goal was to make the dot density
> high enough, the refresh rates fast enough, and through the use of red,
> green, and blue phosphor dots, to create a color flat-panel television
> display. This TV display technology was abandoned once liquid crystal
> display technology rapidly advanced to allow flat LCD panels to be used as
> television displays, as well as computer monitors, smart phone displays,
> tablet screens, laptop displays, displays on kitchen appliances, and
> graphical-display calculators.
>
> Just as a note, there are a couple of other display technologies worthy of
> mention. One was the LED, or light-emitting diode display in calculators.
> These were segmented (usually seven) displays that emitted a bright red
> color for the segments. These were used in some battery-powered handheld
> calculators for a time because they did not require higher voltages like
> gas-discharge/Nixie tubes and vacuum-fluorescent displays, but they were
> also somewhat power-hungry, which limited the size of the displayed digits
> (usually requiring a bubble-shaped lens over the digit to magnify it
> somewhat to make it more readable) and affected the runtime on battery
> power. An LED display was famously used in the Hewlett Packard HP-35, the
> first scientific handheld battery-powered calculator, and many follow-on
> calculators from Hewlett Packard as well as Texas Instruments and countless
> others in the mid-to-late 1970's. The vivid bright-red color of the
> display, with perhaps a red filter over it to provide better contrast, is
> the giveaway for a LED display on a calculator. No other display
> technology used in calculators has this distinctive color and intensity.
> Gas-discharge displays all created an orange-red color, much different from
> that of a LED, and even with a red filter, the orange tint of the Neon gas
> in the gas-discharge display created a color easily distinguishable from an
> LED display. LED displays were eventually phased out of use in
> calculators in favor of liquid-crystal (LCD) displays. Many people confuse
> LED and LCD displays, much like the confusion of Nixie tubes versus other
> types of displays (including vacuum-fluorescent) though the technologies
> and timeframes involved are vastly different.
>
> A calculator display technology that was used on some notable electronic
> calculators was the CRT (Cathode Ray Tube) display. This was a tube
> similar to that in and old black ad white CRT television set, but much
> smaller, and used green phosphor instead of white. The digits were
> "drawn" using line segments to create a rendition of the green or
> blue-green numerals on the screen of the tube. Arguably most historically,
> the Friden EC-130 used a CRT display. Perhaps more recognizably, the
> legendary Hewlett Packard HP 9100A/B scientific programmable desktop
> scientific calculators also used a beautiful CRT display.
>
> A very short-lived display technology used in early electronic calculators
> made by the Japanese calculator manufacturer Canon, used tiny incandescent
> lamps (with a glowing hot filament, as did the light bulbs we used before
> compact-fluorescent and LED light bulbs came about) to edge-light thin
> panels of clear plastic, engraved with a multitude of small dots in the
> shape of a numeral, with the panels stacked atop one-another, creating a
> stack of the numerals and a decimal point, all enclosed in a metal
> enclosure to create a single digit unit. These displays had a
> whitish-yellow color to the digits that had a natural shape like the digits
> in a Nixie tube. There was a separate lamp for each numeral and the
> decimal point inside each display unit. Lighting one and only one numeral
> lamp in a display unit would result in the selected numeral (and possibly a
> decimal point) lighting up, showing through the transparent plastic panels
> in front of it that were not lit. While these numerals were formed like a
> NIxie tube numeral, they were most definitely not a Nixie tube, with the
> giveaway being its whitish-yellow color. Examples of the use of this type
> of display in calculators are the Canon 130 (Canon's first electronic
> calculator), the Canon 161 and 130S, along with a couple of other Canon
> models. This display technology was very difficult to multiplex, requiring
> individual digit decoding/drive circuit for each digit, as well as the tiny
> lamps burning out over time, leading to digits that wouldn't light up -
> definitely a problem on a calculator. The tiny lamps were not intended to
> be individually replaced, requiring the replacement of the entire digit
> module, which, unless under warranty, was both labor-intensive, and
> expensive. This led to Canon switching over to Nixie tubes in later
> calculators, once the patent fuss with Burroughs over Japanese copies of
> Burroughs' Nixie tubes settled down. Canon was quite concerned over
> possible legal troubles of using Japanese-made copies of Nixie tubes, which
> is why they used this unique display technology in their earliest
> calculators.
>
> There was definitely a lot of change in display technologies over the
> years, with LCD and Vacuum-Fluorescent panels being the only that remain in
> current calculators. There type of displays are far different in every
> aspect than the displays used in early calculators, including the Sanyo
> ICC-82 that used either small Nixie tubes (mainly only sold within the
> Japanese market) and the other that came a bit later which used the
> seven-segment gas-discharge tubes.
>
> Again, sorry for the length, but I wanted to be thorough.
>
> All the best to all,
> -Rick
>
>
>
>
>
>
>
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