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Calculators: Handheld: Texet 800M
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Size (actual): |
70.0mm
(max) x 133.3mm x 23.0mm (max) (w,h,d) |
| Power: | 9.0V DC, 1 x PP3 size battery. Also accepts adapter/charger (undefined) through a left side socket about a third of the way down. | ||
| Case: | Cheap feeling two piece shiny black plastic case. Edges are a bit sharper than you would normally expect. Brushed aluminium panel for the brand / model info above the display and keyboard surround below. Titled up towards the back and widens at the top to accommodate the 9V battery. Cheap battery terminals are just two metal tags rather than a proper 9V battery connector. Buttons make a positive load click. Blue and black colour scheme of keys reminiscent of other Texet calculators. On/off sliding switch on the right side, one third of the way down. The dark red plastic display filter and deep-seated display make the numbers difficult to see as is have a very narrow angle of view. | ||
| Display: | 8 digit red LED with bubble lens display - no ninth digit | ||
| Features: | Basic four function with percentages, change sign and four-function memory. | ||
| Age: | 1979 (inspection stick in the battery compartment states 10 August 1979) | ||
| Manufacturer: | Serial Number C953160. Made in Hong Kong. | ||
| Comments: | Very commonly cloned model. Cheaply made but works well enough. Logic is let down by seven digit negative numbers and the pseudo fixed decimal bug. See the Same Calculator page for more clones. |
| Components: | 1 x cpu: Texas TMS0972NL
MBT 7927 Singpore (date code week 27 of 1979), 28 pin DIL,. 0.3"
width black ceramic 1 x 8 digit red LED unit with bubble lenses: National Semiconductor NSA1488 908 No other components |
| Boards: | The main board (8D15 0972 220677 RJP) sits face down on top of the keyboard assembly and is joined by 16 wires. A bit of tape fixes the lowed edge. |
| Construction: | Warning the case is held together by lugs in the lower section. It is very difficult to open without damaging the edging - not recommended. As there are numerous internal lugs, carefully pop then by pushing the front section inwards, starting on a long side. The rear will lift off. |
| Logic comments: | The Clear Entry key (CE) is used to clear an input number, the clear (C) key is used to completely reset the calculator |
| Overflow on the input of a number is suppressed keying in a ninth digit is ignored | |
| The constant function is automatic on all four operations | |
| The negative sign is shown on the immediate left digit but as there is no ninth digit you are limited to seven digit negative numbers | |
| There is no indication of memory storage - you have to remember it. | |
| Overflow error show the result as a flashing number and is recoverable using (CE) | |
| A divide by zero error is shown as a flashing "0" which is recoverable by use of the (CE) key | |
| Overflow in memory result in a flashing number which is not recoverable and you lose the memory contents | |
| It suffered the pseudo fixed decimal bug; key in (1)(+)(2)(.)(0)(0)(=) to get (3.00) which remains a fixed two digit number until you need more or use multiply or divide |
