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Simulating a TI calculator with crazy 11-bit opcodes


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My grandmother used to have one of those.  In fact, I bet she still has it.  I remember it worked great, even through the nineties.  It probably still works.

 

Some of us may remember (or have read about) the discovery of speak-n-spell innards in MiG-25 radar systems.  :)

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Some of us may remember (or have read about) the discovery of speak-n-spell innards in MiG-25 radar systems.   :smile:

 

More info ? :-o

 

Good project idea. Have it implemented physically on a Launchpad w/ 7 segment leds + tactile button array. I already got the hardware setup, just need to find the time....

Looking forward to it!

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More info ? :-o

There doesn't seem to be a lot of information online, and I don't remember the entire story, but a reliable source told me that we found after the cold war that the Soviets had been purchasing speak-n-spell devices in order to harvest a DSP chip.  I think it was used in a radar or guidance system of some kind, maybe for the MiG but possibly for something else.  The Soviets copied all kinds of ICs from us, but their fabrication was a long way behind so I guess it was cheaper to just buy the speak-n-spells.

 

Granted, for years the CIA was purchasing Titanium from the soviet union in order to build SR-71s.

 

Also, not too long ago Saddam was halted while trying to buy a ton of PS2's.

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  • 3 weeks later...

I have been working on something similar for the last few months. Mine is based more on HP calculators, though. I'm using a 20x4 LCD so the interface should look similar to an HP-28 or HP-48 series model. I wanted to add keystroke programming too but the firmware is already at 14K without it. I added a second G2553 so I can hopefully split up the tasks between the two and still have enough flash. I think a G2553 would work fine to remake either of those calculators.

 

Here is my blog in case you are interested: http://joldosh.blogspot.com/

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I have been working on something similar for the last few months. Mine is based more on HP calculators, though. I'm using a 20x4 LCD so the interface should look similar to an HP-28 or HP-48 series model. I wanted to add keystroke programming too but the firmware is already at 14K without it. I added a second G2553 so I can hopefully split up the tasks between the two and still have enough flash. I think a G2553 would work fine to remake either of those calculators.

 

Here is my blog in case you are interested: http://joldosh.blogspot.com/

 

Good work you have there. It's amazing to learn how they did math w/ limited ram / rom back then.

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  • 4 weeks later...

It's bound to happen.

 

 

Currently I am re-using a UI shield from my ez430trainer project. http://forum.43oh.com/topic/3013-ez430trainer-a-retro-style-single-board-computer/

 

I am trying to locate those bubble led displays. It would be interesting to have a single PCB build for a daily use calculator.

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@@abecedarian

 

Right on, exactly what I need. Thanks for the find. I did look at ebay and found another one (same) but the one I found goes for $15+ (w/ shipping) and it's way out of what I want to spend. I will get these to play w/.

 

Now I need to figure out a way to drive them w/o additional circuitry. The look of it requires 9 digits + 8 segments, that's already 17 IO pins, then there is uart, etc. Might need to get the 28pin G2553 (which is OOS from newark.ca, they only have 20pin tssop or QFN). But I always tries to use all thru-hole. What to do? 595s? Decade decoder for digit scanning?.

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  • 8 months later...

Bump.

 

Finally moved the emulator to a single PCB design (after one failed PCB design). Now my kids can take them and use them in school.

 

Source code can be found at https://github.com/simpleavr/tms0800.

 

Source code based on Ken Shirriff and other's work, please see http://righto.com/ti and http://righto.com/sinclair

 

 

A few photos...

 

post-23-0-06093600-1401924896_thumb.jpgpost-23-0-22359100-1401924911_thumb.jpgpost-23-0-59574900-1401924921_thumb.jpg

 

PCB design available upon request.

 

 

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