Hi;
as mentioned by Les in his followup, the initial memory organization in the HP41CX is different of the one in both HP41C and HP41CV. Experienced (and some new) HP41 users know that by heart, but it is harmless to talk about this.
A small remark: the actual amount of memory available in the HP41CV/CX or in the HP41C with four memory modules or one quad memory module is, in fact, 320 registers, but there is always a permanent, 3-byte .END. function in program memory, so users actually have 319 registers + 4 bytes available, or 2237 bytes. No X-memory being considered here.
If you have an HP41CX and it has all memory cleared (MEMORY LOST in the display) and you put the calculator in PRoGraM mode, you'll see
00 REG 219
instead of the common
00 REG 46
found in the HP41C or HP41CV. As the HP41CX has many additional, resident features, I believe the software design team decided it would be a good idea to reorganize the HP41CX´ always available 319 registers such that 100 numbered registers are available (R00 to R99) and all remaining 219 registers + 4 Bytes are allocated to programs.
My 2¢.
Luiz (Brazil)
Edited: 16 Jan 2007, 6:15 a.m.