DATAMATH CALCULATOR MUSEUM
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DATAMATH CALCULATOR MUSEUM |
Texas Instruments TI-5230
| Date of introduction: | 1977 | Display technology: | Fluorescent |
| New price: | Display size: | 12 | |
| Size: | 12.0" x 12.3" x 3.3" | Printer technology: | Thermal TP-20225, TP-27225 |
| Weight: | 6 pounds 2 ounces | Serial No: | |
| Batteries: | Date of manufacture: | ||
| AC-Adapter: | 120 V or 220 V | Origin of manufacture: | USA |
| Precision: | 12 | Integrated circuits: | TMC0501E, TMC0572, TMC0587, TMC0588, 7*TMC0598, TMC0255, TMC1376 |
| Memories: | |||
| Program steps: | 200 | Courtesy of: | Joerg Woerner |
This
rare TI-5230 seems to be an enhanced
version of the TI-5225. We notice 16 added keys
compared with the basic calculator but [START], [STOP] and [ENTER] are not
common labels for a simple desktop calculator.
We decided to dismantle the TI-5230 to reveal its true genes and found a real surprise under the cover of the huge housing. Please watch the following 4 pictures carefully.
| The internal construction of the TI-5230 is a typical design of Texas Instruments. We know the style from the TI-5225 but notice two stacked printed circuit boards (PCB's). |
|
| The lower PCB makes use of two single-chip calculator chips to control both the thermal printer and the display. |  |
| The upper PCB mixes some 28-pin devices with 10 smaller devices. A known relationship... |  |
| Looking closer on the upper PCB gives with the TMC0501E Arithmetic Chip and lots of memory a real surprise! |  |
With the TMC0500 Building Blocks for Scientific and Programmable Calculators Texas
Instruments created a novel architecture for scalable scientific calculators.
The architecture used in a minimum configuration as used with the
SR-50 a 2 chip design with the
TMC0501 Arithmetic Chip and the
TMC0520 SCOM (Scanning Read Only Memory) Chip, but was expandable to a maximum of 8 SCOMs,
additional RAM as program memory for programmable calculators, additional RAM
for general purpose registers and even a chip driving a printer. Most scientific
and programmable calculators from Texas Instruments manufactured between the years 1974 and
1982 rely on these chips. Please find all known calculators using the TMC0500
architecture here.
Combining all numbers found on the integrated circuits of the TI-5230 adds to an impressive Bill-of-Material:
| Part Number | Amount | Description |
| TMC0501E | 1 | Arithmetic
Chip with up to 13 digits precision based on Chipset for scientific calculators |
| TMC0572 | 1 | Bare Read Only Memory (BROM) with 1k*13 Bits instruction memory |
| TMC0587 | 1 | Double Scanning and Read Only Memory (DSCOM) with 2.5k*13 Bits instruction memory and 16*16 digits constants |
| TMC0588 | 1 | Double Scanning and Read Only Memory (DSCOM) with 2.5k*13 Bits instruction memory and 16*16 digits constants |
| TMC0598 | 7 | External Random Access Memory for user programs with 240*8 Bits of read/write memory (240 program steps or 30 data registers) each |
| TMC0255 | 1 | Driver for thermal printer |
| TMC1376 | 1 | Driver for display based on Third generation single chip calculators |
Overall the complexity is centered between the well known TI-59 and the flagship SR-60A!
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, June 11, 2005. No reprints without written permission.
