TI-82 Early Hardware and ROM Versions

→ **MyCalcs** profile · by **Adriweb** » 25 Feb 2017, 00:25

Well it hasn't been uploaded, as usual.

→ **MyCalcs** profile · by **Adriweb** » 26 Feb 2017, 00:17

CVSoft wrote:
Adriweb wrote:
CVSoft wrote:I also blindly purchased a TI-82, serial 0510400 I-0593. We'll see what it has when it arrives (hopefully 3* ). Notably, the serial number is lower than the TI-82's with ROM 3..

Well, I just blindly purchased a bundle of 4 graphing calcs (2x TI-82, 1x TI-83, 1x TI-83 Plus) + a TI-BAII, all for around 50euro (thank you for the tip, btw)

We'll see if there's anything interesting, otherwise we can hope there is going to be some resell value in this...

I think it's also worth noting that the two TI-82s purchased by Adriweb are potentially interesting; we never got to see any serial numbers but the physical characteristics are consistent with other prototypes.

The parcel arrived, and revealed several surprises, including a big one. More to come soon

MyCalcs profile · by **CVSoft** » 26 Feb 2017, 01:10

Adriweb wrote:a big [surprise]

The last known, undumped version, 3*, has been acquired and dumped.

It is nearly identical to 3., differing by two bytes other than the ROM version. Surprisingly, it does not exhibit the Plot( bug, whereas ROM 3. does!

→ **MyCalcs** profile · by **Adriweb** » 26 Feb 2017, 01:20

CVSoft wrote:It is nearly identical to 3., differing by two bytes other than the ROM version. Surprisingly, it does not exhibit the Plot( bug, whereas ROM 3. does!

Apparently, they patched a dec de into a nop (preserving the final binary size), meaning that this register was being decremented twice instead of once

It's fun to see that this tiny (but critical) difference is the only reason why this OS exists.