- 7-digit serial numbers were used until January 1994, when TI switched to using 8-digit serial numbers.
- The first two digits of a serial number change at least once a month, and rarely more than once a month. An example of the latter is March of 1994, when serial numbers 15xxxxxx I-0394L and 16xxxxxx I-0394M are both present in that month of production.
- The first two digits of a 7-digit serial number directly corresponds with the month of manufacturing, e.g. 05xxxxx I-0593, and 06xxxxx I-0693.
- The last five digits of a 7-digit serial number do not appear to be in chronological order, however I do not have a lot of concrete evidence to show what those digits may actually mean. The rapidness of the ROM version changing in the I-0593 TI-82s provides an excellent method of gathering relative production dates, assuming that TI upgraded the ROM chips' firmware in chronological order.
- Even within very small (n<3500) changes in serial number, significant changes in hardware revision and ROM versions can be observed. Additionally, as per the previous point, these changes bear no particular order: I have observed the order 12.0 --> 8.0 --> 10.0 --> 9.0 all within the space of 6000 serial numbers, sorted here in ascending order of serial number (0605463, 0608697, 0615716, and 0623045, respectively).
Furthermore, I have made the following tentative (and possibly incorrect) observations:
- All hardware versions between A and F were produced in less than a month. HW pre-A and HW-F were both produced in June 1993.
- Starting with HW-E, ROM chip+version and hardware revision are correlated.
- Calculators with HW-E and HW-F have ROM 10.0. Before 10.0, the hardware revision is not labeled.
- HW-F is a version of HW-E that uses a mask ROM instead of an OTP-ROM, and is produced about a month later (after HW-H, oddly). See this post for more details.
- Calculators with HW-G have ROM 11.0.
- Calculators with HW-H have ROM 12.0.
- Calculators with HW-I have ROM 15.0. This makes the existence of ROMs 13.0 and 14.0 unlikely.
- HW-J could be ROM 16.0 on a OTP-ROM chip. I will investigate HW-J after I complete my work with previous HW versions.
As of 18 August 2015, this is the list of all possibly known OS versions:
- 1.0 (referenced at United-TI, subsequently owned by CVSoft, dumped)
- 3. (owned by CVSoft, previously unknown, subsequently listed at Ticalc, dumped)
- 3* (listed at Ticalc, not dumped)
- 4* (listed at Ticalc, subsequently owned by CVSoft, dumped)
- 7* (listed at Ticalc and Datamath, mostly compatible with JASS and OS-82 assembly shells, owned by CVSoft, subsequently dumped)
- 8.0 (listed at Ticalc, owned by CVSoft, subsequently dumped)
- 9.0 (previously unknown, owned by CVSoft, subsequently dumped)
- 10.0 (listed at Ticalc and Datamath, owned by critor and CVSoft, found on eBay, dumped)
- 11.0 (listed at Ticalc, owned by critor, dumped)
- 12.0 (listed at Ticalc, formerly owned by Datamath, owned by CVSoft, first dumped by critor)
- 15.0 (listed at Ticalc, found on eBay, owned by Adriweb and CVSoft, dumped by Adriweb )
- 16.0 (common version)
- 17.0 (common version)
- 18.0 (common version)
- 19.0 (common version)
19.001 (reported at ticalc, possibly typo) 19.002 (reported at ticalc, possibly typo)
- 19.006 (common version, found on Parcus models)
Software Bugs in Pre-16.0 ROMs
As I find new information and acquire more rare TI-82s, I will update this information to factor in the new information.
- PCB images of the TI-82s that I own are available; click here to jump to the relevant post. Hardware versions pre-'A' (three of them), 'E', 'H', and 'Q' are shown.
- The ROM routine table has changed in length throughout various ROM versions, and provides indication of the existence of ROM 9.0: click here to jump to the relevant post.
- The first ROM version found to appear with a mask ROM is ROM 10.0, at HW-F. HW-E is the OTP-ROM-based counterpart. Click here to jump to the relevant post.
- The *-series of ROMs (3*, 4*, 7*) were entirely produced in May 1993, and do not have a hardware revision labeled. It is very well possible that the *-series is a bugfix of the 'normal' ROMs; see the bug list.