The HP-38C and HP-38E were the high-end business members of the 30 series. The HP-38E was introduced first, followed a year later by the HP-38C which added continuous memory.
The HP-38E/C were the first HP programmable business calculators. Previous high-end business models had relied on the large amount of software in ROM to handle most business problems. Thanks to the decreasing costs of ROM and RAM, the 38E/C could provide those previous built-in functions and allow user programmability at an attractive price.
For about 30% less than the price of the previous generation HP-22, the HP-38E provided not only programmability but a much larger financial function set including amortization, internal rate of return, discounted cash flow analysis and net present value. While the HP-22 easily replaced the HP-70, it wasn't until the HP-38E was introduced that the HP-80 was finally discontinued.
A first on the HP-38E/C was shared memory for programs and data storage. The calculator started with 20 numbered registers (R0-R.9) and 8 lines of program space and converted registers as needed into program lines. Register conversion started from the top (R.9) and proceeded downward to R7 with each register yielding 7 lines of program space. R0-R6 were always used for data which meant that programs could be up to 99 lines in length. (The financial registers were separate and never converted.)
Prices: HP-38E: $120 HP-38C: $150