New Stuff
Author
Links
Guest book
Web-log
Bric-a-brac
Calculators
Components
Ephemera
Events
Glossary
History
Hit or Miss
Radios
Transport
Valves
Wanted
Metal Puzzles
Clocks
Calculators: Handheld: Casio Mini (aka CM-604)
|
|
Size (approx): | 156mm x 80mm x 31mm
(w,h,d) Weight 192g excluding batteries |
|
Power: |
6V DC, 4 x AA size batteries. It accepts an adapter (AD-4145, 0.4W) through a socket on the top side to the far right. Manganese dry battery quoted life is eight hours whilst alkaline is 18 hours. | |
| Case: | Horizontal format two-piece case in dark brown and beige smooth plastic. The inset and slightly tilted neutral display filter is framed by a white printed escutcheon. A further inset panel has printed model number and reversed out Casio name. Large, long travel hollow sounding keys work well. The display filter gives a bright clear image with odd "small zero" notation (see below). There is a small plastic tab on the left side for a carry strap that was originally included with the calculator. | |
| .Display: | 6 digit blue VFD, with no seventh digit for additional display. A shift-display key helps out. | |
| Features: | 4 function calculator with display shift. | |
| Age: | 1974 | |
| Manufacturer: | Casio Computer Company Ltd. Made in Japan, serial No. 6214352 (on battery cover). | |
|
Comments:
|
One of a range of early, solidly built horizontal calculators by Casio. The Mini name with some variations was used for a range of similar calculators so it is best to differentiate them with the CM number if available. Quirky logic and annoying display (used to save money and power) is made up by the wonderful divide by zero bug! The original soft black plastic case has a double end flap with popper closing and is embossed with Casio on the front and Made in Japan on the back. |
| Components: | 1 x cpu: Hitachi HD32170AP 4F2
(date code 2nd week of June 1974) 28
pin DIL, 0.6" width 1 x 6 digit VFD display single glass tube 5 x transistors 8 x diodes 15 x capacitors 2 x SIL resistor arrays 13 x resistors 1 x transformer: Fuji MCT0625A 4F10 |
| Boards: | The keyboard board (ref 6P-E4A) sits loosely on the battery compartment and is fixed to the main cpu board by 9 stiff wires. The latter is crammed full of components. As the batteries all line up the same way numerous cross wires have to be used to wire them up in series. |
| Construction: | Remove the single screw from the right hand side and gently prize off the front by popping the two lugs in the middle of the top and bottom side. Not for the faint hearted - so do not attempt if you want to keep the calculator pristine. |
| Logic comments: | The (C) button is used to clear last entry of a number and the (AC) to clear the whole calculator. |
| Overflow on number input is suppressed, typing in a seven digit number ignores the seventh digit. | |
| An overflow error is flagged with the answer displayed and viewable using the shift key (>) and is not recoverable | |
| Divide by zero results in "000000" being displayed - but use the shift key to see the clock running! It is not recoverable. | |
| There is automatic constant on all functions | |
| Negative numbers are shown by a "-" in the far left sixth digit until it gets too big where you will see it on the first digit of the shift display |
Note the unusual way that zero is represented - by only using the lower half of the digit. |
|
The black and white manual on the left measures
148mm by 105mm and contains 12 printed pages. It has basic info and
some useful examples.
Printed in Japan |
