Calculators with equation storage and multi-letter variable names

[Dave Britten]

I'm trying to find calculators - of any brand - that allow storing algebraic equations containing variables that are more than just a single letter. Bonus points if they let you solve numerically for any variable rather than just evaluating the expression. I know there was a similar discussion on this board a while ago (and which I couldn't find) regarding current calculators that can store equations, but I'm also interested in older models that have this capability.

Some that I know of that can store equations and solve for any variable:

HP 18C, 17BII, 19BII, 27S, etc. - These all have the HP solver which is probably the best implementation of this functionality.
HP 28C, 28S, 48-50 - I believe these all have an equation solver, don't they?
TI-67
TI-85, TI-86
TI-92, TI-89, Voyage 200
Sharp EL-9300 - Uppercase letters are single-letter global variables, lowercase letters can be used for multi-letter temporary variables. Strangely, all their later graphing calculators removed the lowercase temporary variable feature.
Casio Classpad - I'm pretty sure these have this capability.
HP Prime

A few more limited ones:

TI-68 - I think you can use up to 3 letters for a variable name, though it only evaluates and doesn't solve for any variable.
Sharp EL-5120 - Allows for two-character variable names consisting of one letter and one digit. Can solve for any variable.
Sharp PC-1260, PC-1261, PC-1262 - Stores and evaluates equations, but no solver.
Casio fx-5800P - Can store and evaluate equations with two-character variable names. Solver can only be used on equations with single-letter variables.
Casio fx-5000F, fx-1000F - Stores equations with two-character variables (like the fx-5800P), but no numeric solver.

Close but no cigar:

HP 32SII, 33S, 35S, 22S - Stores algebraic equations that can be evaluated or solved, but single-letter variables only.
Sharp EL-9400, EL-9600, EL-9900 - Basically the same as the EL-9300, but single-letter variables only.

Anything else to add to the list?