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Calculators: Handheld: Unisonic 21 Blackjack (aka 21-P1B) (aka Jimmy the Greek)
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Size (approx): |
80mm x
142mm x 18mm (w,h,d) |
| Power: | 4.5V DC, 3 x AAA size batteries, 0.35W. It accepts an adapter (model SY1200 or 620) through a socket on the top side to the far right. | ||
| Case: | Two-piece black smooth black plastic with practically all-encasing aluminium panels. The top front is dominated by a raised and flat black plastic section that is green and white printed for brand and model information. A green window gives a bright image of the digits. The keyboard is surrounded by black printed area with reversed out text for extra labels. The shallow keys are short travel with a positive click and work well enough. | ||
| Display: | 12 digit green VFD which operates in an 8+1 mode as a calculator with the ninth digit used for negative indication. In game mode it operates as a 5+5 display. | ||
| Features: | Standard four functions with blackjack game. | ||
| Age: | 1977 | ||
| Manufacturer: | Made in Taiwan, serial No. 059590 | ||
| Comments: | Lovely solid slim design that was to become the norm in the early LCD era. Unisonic (and others) did a range of Blackjack handheld games/calculators with the Jimmy the Greek branding. You have to switch the machine off to change the mode from calculator to game machine - which throws you for a while. The calculator logic is poor with no recovery and the negative zero bug. The original cover is brown stiff plastic wallet with clear plastic holders for the calculator and a manual. It is printed with silver text with "Unisonic 21" and "Jimmy the Greek" on the front and embossed with Made in Taiwan on the back. |
| Components: | 1 x cpu: Rockwell A4821EB
7744 (date code week 44 of 1977) 42 pin staggered DIL, 0.6" width
black ceramic 1 x 12 digit VFD display flat face single tube. 2 x transistors 4 x diodes 6 x capacitors 10 x resistors 2 x resistor arrays 1 x transformer |
| Boards: | The keyboard assembly (GICO Japan A5500 1048 52.8.12) sits above the main cpu board and is joined via 13 stiff wires. The latter sits lose guides by some plastic lugs. The main board has numerous cut-outs to mid-mount the fatter components (transistors and larger capacitors) to reduce the width. |
| Construction: | Difficult top open as it is held together by internal lugs only and the sides are quite stiff. Damage is highly likely so I wouldn't bother if I were you. I found the easiest (and most dangerous) way was to lever apart the top edge as this is the weakest (and most liable to break so be gentle. Push the back section inwards at the sides to pop the lugs. The front will eventually lift off. |
| Logic comments: | To use as a calculator: switch off, switch to Calc. then switch back on |
| (C) is used to once cancel the last number entered and a second time to clear the whole calculator | |
| There is automatic constant on all four functions | |
| Input overflow is suppressed, inputting a ninth digit is ignored | |
| Negative numbers are shown with a "-" in the mid left (ninth) digit thereby allowing full eight-digit negative numbers | |
| Overflow shows the result with all (nine) decimal points alight and is not recoverable | |
| Divide by zero shows ".0.0.0.0.0.0.0.0.” and is not recoverable | |
| It suffers the negative zero bug: key in (1)(-)(2)(=) to give "-1" then (+)(1)(=) to give "-0" | |
| To use as a Blackjack game: switch off, switch to Game then switch back on | |
| Power up shows ".0.0.0.0.0.0.0.0.” rapidly flashing which is the bankrupt state | |
| » Press (C) which clears the state and leaves the display with one zero rapidly flashing | |
| » Key in your initial float of money, say 300 with: (3)(0)(0)(BET), display now shows zero | |
| » Key in your first bet: (1)(0)(BET) and the hand starts to deal, you on the left, dealer on the right | |
| » To turn another card press (HIT), to finish you hand and stand press (STD) | |
| » The dealer will then complete its hand but you do not get any indication that you have won or lost - key (TOTAL) to see your new pot of money | |
| » To play again key in (PLY) for play, enter a new bet (1)(0)(BET) and play will resume as above. | |
| » When you get two cards the same you can play two hands by using the (SPL) split key and continue as above |
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