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Calculators: Handheld: Commodore 887D

Size (approx): 75mm x 144mm x 24mm(max)  (w,h,d)
Weight 108g excluding batteries


9V DC, using 1 x PP3 size battery.  Does accept an adaptor (505 or DC-620R 3mm plug, centre positive) through a socket on the top side on the far right.  Remove battery before using adaptor.
Case: Two piece matt plastic case in dark brown and beige.  The keyboard surround is in  matching dark brown whilst the panel below the display is glossy black with a silver printed  logo.  Typical key colour scheme from Commodore and the small keys are very squishy but work well enough.  The red plastic flat filter over the display is flat and heavily inset so that the case forms a light screen.  Display is very clear and large though rather limited in viewing angle.
Display: 8 digit red LED with bubble lens with a ninth digit for negative, memory and error indication.
Features: Standard four functions, percentages, register exchange and four function memory.
Age: 1975
Manufacturer: Commodore made in USA, serial number 168484


One of a large range, I think these wider models are much more attractive than the thin ones.  The logic is very sound with good recovery and flexible memory.  Surprisingly advanced for its age with minimum components - just right for the aggressive market of the time.  Very similar in design to the later 887ND.

Components: 1 x cpu: Commodore GRBP-89 7527 (week 27 of 1975), 24 pin DIL, 0.6" width, grey ceramic
1 x IC: ITT 548-5N 7522, 22 pin DIL, 0.3" width black plastic
1 x 9 digit single unit bubble lens LED display
1 x resistor
Boards: The main CPU board (PCB 200570 Rev A TO-ITT ) rests above the keyboard assembly (KB-6373-01) loosely and is connected through a 14-way ribbon cable.  The latter is held in place by four plastic lugs to the front.
Construction: Remove the two screws from the back of the case.  Gently push the two lugs in the lower section cuts outs and squeeze off the back.  There are two inner lugs that can be seen from within the battery compartment. 

Logic comments: (C) is used once to 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 an ninth digit is ignored
Negative numbers are shown with a "-" in the immediate left hand digit travelling into the far left (ninth) to allow eight digit negative numbers.
The (MR) key recalls the memory, the (MT) key recalls and clears the memory
Memory store is indicated by the far left (ninth) digit's decimal point
It is possible to store an overflow in the memory and later recover it by continual division by 10
Divide by zero shows "E00000000"  (no decimal point) and is recoverable by dividing by one
Overflow shows the result with "E" (negative or positive) in the left most (ninth) digit and is recoverable by continual division by 10 (or a multiple)
(EX) is used to exchange the display with the register
The (%) button divides by 100 so can also be used to recover from overflows
No bugs found

897D box

This calculator-sized box measures 80mm x 150mm x 27mm (H x W x D) and is printed in three colours with a "jazz-tech" image.  This particular example has printed "model" and "Serial No." on the top flap but the red printed text is too faint to read.  

The scan on the left shows the main board with only the CPU, display driver and display, with one resistor.  For its age this was quite advanced.  The board really didn't need to be this long, it just made mounting easier.  You can just see the ribbon cable at the bottom that connects the the keyboard assembly.