OT: Simulating a TI calculator with crazy 11-bit opcodes
#1

http://files.righto.com/calculator/TI_calculator_simulator.html

#2

That's quite awesome, thanks for the link :)

#3

A TI 57 is a 13 bit opcode machine :)

See patents: 4125901 4125867 4107781 4079459 for a rom dump

For testing, get go57c on google play or TI-57E from hrastprogrammer for hp 48/49

You can even use TI-57E on go48gx and go49g.

The HP50 version of TI-57E doesn't works well on go49gp (certainly some remaining bugs on go49gp)


Edited: 12 Aug 2013, 8:07 a.m.

#4

Hi Olivier

FYI, John McMaster has hi-res photos of the TI-57 chip: see
http://siliconpr0n.org/archive/doku.php?id=mcmaster:ti:tmc1501nc and http://siliconpr0n.org/map/ti/tmc1501nc/top_metal_mit20x/

I note that HrastProgrammer fixed a few bytes in his emulator, as compared to the patent. Did you make all the same fixes? Most are OCR errors but at least a couple are not.

Here are the differences between the microcode in the patent and that in the windows simulator:

25:   1abc   1a8c
91: 1aSd 1a8d
487: 19822 1982
521: 0e07 0eff
522: 0e07 0e0d
536: 0cbd 0eff
591: 07eb 07e8
641: 1abc 1a8c
646: 17b0 1780
648: 1abf 1a8f
707: 0bc7 08c7

Cheers
Ed

#5

Yes I corrected some words. Some due to OCR, but other to restore the RST behavior of the real 57 (the listing in the patent did not have the same behavior on RST command).

A new opcode was also added to allow a light sleep mode for the emulation (to avoid consuming too much batterie)

#6

Quote:
http://files.righto.com/calculator/TI_calculator_simulator.html

This is a very interesting site. Thanks for its citation. After I bought my first calculator in 1972 (Bomar 901B, $130), I was intrigued by this sort of detail hidden within even simple machines.

The simulated calculator seems to stop functioning after a division by zero...the display no longer updates.

#7

Quote:
thanks for the link

1+


Quote:
Making a scientific calculator from this chip

The most amazing thing about this chip is that the Sinclair company took this chip with barely enough ROM to do four-function math, and reprogrammed it into a scientific calculator with trig, inverse trig, exponentials, and logs. The resulting Sinclair Scientific calculator became popular due to its low cost.

How did Sinclair fit all this into 320 words of ROM? The short answer is they used RPN which simplified the code, and they made extreme tradeoffs in the scientific algorithms that reduced accuracy and performance. The algorithms are a bit like decimal CORDIC, but much simplified. I plan to provide full details later.


Let's hope that ROM is available as well. That might be nice to have this calculator emulated as well.

Cheers

Thomas

#8

Quote:
This is a very interesting site.

Yeah it really is. The 8085 ALU was a very interesting read as well.

Quote:
The simulated calculator seems to stop functioning after a division by zero...the display no longer updates.

I wonder what the real thing did.
#9

Another bug. Generate an overflow e.g. 1000 * = = and it endlessly loops at the .OVF label.

- Pauli



Possibly Related Threads…
Thread Author Replies Views Last Post
  OT: Graphing calculator for Android ? Ivan Rancati 4 1,836 11-18-2013, 12:33 PM
Last Post: Alberto Candel
  bit manips on WP 34S Kiyoshi Akima 8 2,377 10-06-2013, 06:25 AM
Last Post: Paul Dale
  Where to the 32-bit version of User Code Utiltiy for HP-41 ? Olivier (Wa) 2 1,469 09-26-2013, 01:55 AM
Last Post: Olivier (Wa)
  OT TI-59 for the iPhone Matt Agajanian 10 2,820 09-04-2013, 08:57 AM
Last Post: Eddie W. Shore
  OT-The ideal calculator Matt Agajanian 0 901 09-04-2013, 01:11 AM
Last Post: Matt Agajanian
  OT: Reversing Sinclair's amazing 1974 calculator hack - half the ROM of the HP-35 Egan Ford 6 2,716 09-02-2013, 10:54 PM
Last Post: Thomas Klemm
  OT--TI-36X Algorithms Matt Agajanian 48 11,064 09-01-2013, 08:13 PM
Last Post: robert rozee
  WP-34S Overlay - making it a bit more permanent? Marcel Samek 1 1,080 07-05-2013, 09:02 PM
Last Post: htom trites jr
  OT: anyone use the TI BAII Plus calculator a lot ? Gene Wright 1 1,138 06-15-2013, 01:08 PM
Last Post: John B. Smitherman
  OT: RPN calculator/dmm by ESI Kees van der Sanden 2 1,488 05-25-2013, 01:38 PM
Last Post: Kees van der Sanden

Forum Jump: