TI-59 / TI-58
The TI -59 is a programmable technical- scientific calculator from Texas Instruments with built-in magnetic card reader. He arrived in 1977 as at that time the top model of the manufacturer on the market. He was the successor of the well -equipped with magnetic card reader SR -52
- 4.1 display in programming mode
- 4.2 Undocumented functions
Temporal classification
At the time of market launch on 24 May 1977 by Texas Instruments TI -59 introduced the competition model for similarly configured HP -67 from Hewlett -Packard is, which had a better mechanical build quality, however, could count only about half as fast, with less memory equipped and also cost about twice the TI -59.
A sister model without magnetic card reader and only half as much memory, the TI -58, was offered simultaneously. The TI -58 was soon replaced by the improved TI- 58C, which was ( for the first time at TI calculators ) equipped with a so-called Constant Memory whose contents were not deleted when you turn off the computer.
Coinciding with the TI -58 and TI -59 TI -57 was introduced, which rounded off the family down.
In 1979, Texas Instruments replied ' main rival Hewlett -Packard with the much more powerful, more advanced, but also much more expensive HP- 41C was with an alphanumeric LCD display, non-volatile RAM (expandable ) and four module bays equipped.
Technical Features and functions
The TI -59 is the most powerful TI calculators, which is still equipped with a red LED seven-segment display. For permanent assurance of the programs created by the user himself (and data) are used depending on the program size up to two magnetic cards.
At launch, the TI -59 exchangeable program modules offered the world's first pocket calculator, semiconductor-based (ROM) with hard-coded application programs ( "Solid State Software").
A standard already supplied standard software module ( master library ) contains 25 programs in the fields of matrices bill, complex functions, integral calculus, geometry, statistics, financial mathematics, Unit conversion, a calendar program, a simple game as well as a diagnostic tool for functional testing the computer and available as an accessory thermal paper printer.
RAM
The memory can be divided into 11 steps between program and data memory. Each level consists of 10 data memory or 80 program steps. There are at least 160 program steps and data memory 100 and a maximum of 960 program steps available without data storage. The default setting after switching on the computer are 480 program steps and 60 data memory.
Program memory
A program step corresponds to two nibbles and a byte of storage capacity.
Data storage
A numeric data memory ( 13 digits mantissa 2-digit exponent sign) occupies 8 program steps, which theoretically corresponds to 8 bytes, but in practice 16 Nibbles because the calculator works with its 4- bit CPU nibble - oriented.
Programming
Programming the TI -59 is done by simply pressing the desired key functions in the LRN mode. When you run the program, the computer processes the recorded list of pressed keys. The programs on the user side created are usually on the keys A through E started ( and their second assignments 2nd - E - A to 2nd).
For program flow control, the TI -59, for example, a Start-/Stopp-Funktion, counting loops, conditional jump instructions, multiple, nestable each other subroutines that direct and indirect addressing of data storage or program steps, simple symbolic program brands (labels ) and program control over 10 simple binary flags.
Display in programming mode
The seven-segment display used can not display letters. In programming mode, therefore the display of program steps are in addition to the three-digit program step number as a two digit number code. The code number corresponds to the row and column position of the key pressed on the keyboard.
The numeric codes "00" to "09" correspond to the simplified readability directly the numeric keys 0 to 9
In order to save program memory, among other things, the code for the second key assignments used as the numerical value of the key position plus 5. The press on the 2nd button thus does not occupy any additional program step.
Some of the possible two decimal number codes may be used for indirect addressing - eg RCL 2nd Ind is displayed as " 73 ".
The key sequence x ² x 3 = R / S RST corresponds to the representation:
To facilitate reading this rather cryptic representation of the computer was a transparent keyboard Auflegefolie with printed in blue at number codes.
Undocumented functions
In addition, there are functional undocumented commands, such as the HIR commands for direct access to the normally only used internally for staples hierarchy and statistical functions, " Hierarchical Internal Registers".
Number format and calculation accuracy
The internal number format is 13 decimal places in exponential notation with 2- digit exponent plus respective sign. Of these 10 digits mantissa are shown with double-digit exponent and sign, thereby increasing computing inaccuracies from rounding errors are less obvious.
However, the accuracy of the computational algorithms of this generation TI calculators is not as mature as the main rival Hewlett -Packard, who made the transition from the sister models HP -67 and HP -97 HP -41C during the market presence of the TI -59.
Optional Accessories
The optionally connectable thermal paper printer PC - 100C enables not only the expression of calculation results to be printed out programs line by line listing of alphanumeric keys and numeric code representation, as well as programmatic or manual expression of up to 20 letters and / or numbers per line.
Specifications
- CPU: TMS0501 - 4-bit CPU, clock frequency 227.5 kHz ( or 192 kHz for the TI -58)
- RAM: 4 x TMC0598 each with 1920 bits = 960 bytes
- ROM: 1 x 1 x TMC0582 TMC0583 TMC0571 x 1 = 6 KB
- CROM: 1 x TMC0541 as an interchangeable program module with 5000 bytes
- Display: 10 2- digit red 7-segment LED display
- Power supply: Via supplied Netz-/Ladeteil or exchangeable NiCd battery ( 3.6 V)
- Interface: 12-pin bit serial port for the printer PC - 100C
- Storage media: magnetic cards ( TI -59 ) with 4-track recording