NEW: HP 15C Collectors Edition

[ijabbott]

(05-07-2023 05:56 AM)Steve Simpkin Wrote:  

(05-06-2023 12:56 PM)ijabbott Wrote:  ...
I can't see the original Pioneer cases making a comeback, but a 42S CE in the form factor of the silver 17bii+ would be nice.

I can't be 100% sure but the HP 17BII+ *may* be a complete re-write of the HP 17BII functionality without using the original ROM firmware or Saturn emulation. I base this possibility on the Wikipedia entry that claims "The newer 17bII+ (F2234A), introduced in 2007, with Sunplus Technology SPLB31A CPU was developed and is manufactured by Kinpo Electronics." This is a similar to the CPU used for the HP-12C Platinum, HP 33S and HP35S, none of which used Saturn emulation.

If this is the case, it may be difficult to repurpose the HP 17BII+ platform to turn it into a HP-42S. Performance wise, I don't believe the 8-bit SPLB31A would be a good candidate for Saturn emulation.

Yes, you are probably correct that a re-write of the 42S functionality would be needed, which would be a big job and likely to introduce new bugs (which was certainly the case for the 17bii+). Also, the hardware platform is getting pretty old now. If the 17bii+ ever gets ported to a new CPU when the current CPU goes out of production, that may be a good time to think about a new 42S, especially if the new platform could emulate the Saturn at a reasonable speed to reduce the amount that needed to be rewritten.

Quote:Its 4288 bytes of RAM would also not be enough to accomodate a HP-42S emulation and 7.2K Bytes of memory space.

The 17bii+ has 30740 bytes of user memory and some quantity of system memory, so it must be using either the external bus memory interface or the serial (I2C) SRAM interface to interface to some external memory.