HP-71b - Future "SD-RAM" Module - viable ?

[J-F Garnier]

(09-06-2022 08:39 PM)Garth Wilson Wrote:  I, too, have kept hoping someone would introduce such a product; but instructions should be compatible with the HP-IL file-access instructions that are already in the HP-IL module, and I think it would have to be an HP-IL device. This goes for the 41 also, even though a MicroSD card would fit in a top-port module which mechanically would be a neater solution (assuming you have a port available).

No, it doesn't need to be a HP-IL device, actually linking it to the HP-IL would be complicate, do you image two HP-IL cables coming from the HP-IL module to the SD card module, and then going outside to regular HP-IL devices? Well, the HP-IL ROM is able to manage 3 HP-IL loops, so it could be possible to emulate a separate HP-IL interface dedicated to the SD card. Still quite complicate.
An other possible approach would be to manage the SD card as a new device type for instance XMEM (like the 75C POD) or EDISC. The HP-71B system is designed in such a way that the HP-71B will poll the LEX files for a handler for unknown device types (this is how the HP-IL ROM extends the built-in command CAT, COPY , ...). So all you would have to do is to write a LEX file to manage your SD card, in the way you want.

(09-06-2022 09:35 PM)mfleming Wrote:  Think of the Bluetooth module as a wireless PIL-Box . . . driven by an emulated HP-IL interface.

Something like this: HP-IL Bluetooth PIL-Box ?

Let me also remind you the IL Drive (a HP-IL disc emulation using a SD card) built by Tobie several years ago based on the PIL-Box.

J-F