RCL-57

[pauln]

(05-12-2022 04:28 AM)Matt Agajanian Wrote:  Sounds fascinating. Would the data registers and program memory be increased? I would think that 224 program steps or more with 30 registers or higher should be a good starting point.

Although I had a 58C (as a upgrade from my 56), I would have liked to see the 58/59 series with fully merged keystrokes to compete with the HP-67/97’s implementation of fully merged keystrokes.

That's an interesting idea. That would be pretty much like the HP-67. I would settle for 100 steps and 10 registers (instead of 50 and 8 respectively) like the HP-65.

Beating the 50-step barrier may be relative straightforward, as long as one is satisfied with the existing 10 labels (I am).

The difficulty is expanding from 8 registers to 10, preferably dedicated. The TI-57 shares some of the users registers with the AOS stack and the t-register (for conditional branching). Another difficulty is that all of the 256 opcodes are already taken (for example there is an opcode for "RCL 7" and another one for "INV Prd 2") so it's not clear how to fit the required new instructions such as "STO 9".

If I could solve these issues, I would take on the project (100 steps + 10 registers).

With 50 steps, I was able to fit a non trivial program that, given a number, finds the closest fraction. But a full biorhythm program seems beyond its capabilities. There is a biorhythm program in the manual but it requires the user to do a lot of computations by hand.