HP 48G - what next?

[pier4r]

2: the USB should be standard, the best thing is that you can power the calculator with USB only even without batteries. Only few casios (9860 and the cg50 once started), prime and nspire allow this.

3: As far as I remember yes. As long as the sd is under 4 GB it should work. Otherwise you should be able to find people that sell bunch of old but functioning sd cards. I still have a 256 mb sd in the 1st hp 50g that I giften to myself in Dec 2010. For the others I used a SD adapter for micro sd of 2gb picked from nokias that I am not currently using.

[Massimo Gnerucci]

(03-01-2019 09:48 AM)pier4r Wrote:  2: you can power the calculator with USB only even without batteries. Only few casios (9860 and the cg50 once started), prime and nspire allow this.

And Swissmicro's DM42.

[cdmackay]

(03-01-2019 09:30 AM)JSS Wrote:  2) 50G 's USB port, is it fully standardized (e.g. USB1.0 & normal voltage levels) and supports similar functionality than using the serial cable connection?

3) Finally, about max 1 GB SD memory cards, they state that 50G supports FAT32 only partially and is restricted to max 1GB, but does it accept larger memory cards if formatted into 1GB partitions?

I don't know about the serial connection, but the USB connection can be used as a serial-type connection, allowing Kermit/XMODEM transfer, just like serial on an HP48. And to power the 50g, as people have said. Or you can just use the SD card to transfer things.

There's no need to format an SD (not SDHC) card (up to 2GB) into partitions.

The largest SD card that the 50g can format is 1GB. But it can use up to 2GB SD, which is the limit where SDHC starts — the 50g cannot use SDHC cards, i.e. greater than 2GB (possibly if they are partitioned into 2GB chunks? I don't know)

Cards above 1GB can only be formatted on a computer. The best format to use is FAT-16, which is required for SD-based ROM upgrades/reflashes.

There is not enough space in the 50g filer to report all the digits, for 2GB cards, so the 1 in front is missing. However, the 50g can still use all the space.

I hope that helps.

[ijabbott]

(03-01-2019 05:20 PM)cdmackay Wrote:  

(03-01-2019 09:30 AM)JSS Wrote:  3) Finally, about max 1 GB SD memory cards, they state that 50G supports FAT32 only partially and is restricted to max 1GB, but does it accept larger memory cards if formatted into 1GB partitions?

There's no need to format an SD (not SDHC) card (up to 2GB) into partitions.

The largest SD card that the 50g can format is 1GB. But it can use up to 2GB SD, which is the limit where SDHC starts — the 50g cannot use SDHC cards, i.e. greater than 2GB (possibly if they are partitioned into 2GB chunks? I don't know)

I think it only uses the first FAT partition. I understand that some people create a small, first partition for the 50g and add another partition for general computer use, but I'm not sure that's worth it these days for an old, slow, 2 GB SD card!

Quote:Cards above 1GB can only be formatted on a computer. The best format to use is FAT-16, which is required for SD-based ROM upgrades/reflashes.

Also, making it FAT32 results in markedly slower turn-on times on the 50g, at least when formatted with the default parameters. That's probably due to increased FAT table size or maybe increased root directory size compared to FAT16.

Quote:There is not enough space in the 50g filer to report all the digits, for 2GB cards, so the 1 in front is missing. However, the 50g can still use all the space.

Not that it's likely to get full, unless you're using it for data logging or something.

[cdmackay]

(03-01-2019 08:55 PM)ijabbott Wrote:  I think it only uses the first FAT partition. I understand that some people create a small, first partition for the 50g and add another partition for general computer use, but I'm not sure that's worth it these days for an old, slow, 2 GB SD card!

Right. I meant that I wasn't sure whether a 4GB card — which would have to be SDHC — could be used even if it had a 1GB or 2GB first partition, if the 50g doesn't support SDHC cards at all?

Quote:Also, making it FAT32 results in markedly slower turn-on times on the 50g, at least when formatted with the default parameters. That's probably due to increased FAT table size or maybe increased root directory size compared to FAT16.

blast! I meant to add that too, but forgot, sorry.

[rprosperi]

(03-01-2019 09:30 AM)JSS Wrote:  1) Anyone knows about the 50G 's non-standard RS232 low voltage level serial port? A special cable which includes low voltage level driver electronics is needed, but does someone still sell them?

Eric at hpcalc.org sells a cable specifically made for the 50g serial port, details are here: https://commerce.hpcalc.org/serialcable.php

Though out of stock at the moment, send Eric an email that you want one; he makes batches of them from time to time, and you can get your name on a list (along with mine and a few others I believe) for the next batch.

The serial port is rather odd, so I'd be careful which cable you use to not damage the 50g; your best bet is this one, if you can wait.

[rprosperi]

Thanks cdmackay and ijabbott, for your comments; I think all the key points on 50g SD card usage are covered in posts #43-45, in a nice compact format, good to bookmark for the next time the question comes up.

[JSS]

I found this forum just a few weeks ago and it has been a great source of 50G related knowledge!

Thanks again pier4r, cdmackay, ijabbott, rprosperi and others for your invaluable comments!

BR JSS

[cdmackay]

(03-02-2019 07:48 AM)JSS Wrote:  I found this forum just a few weeks ago and it has been a great source of 50G related knowledge!

yes indeed, that was me too, quite recently

thanks to all who answer on here regularly.

[mipa83]

Dear all,

I think a follower for the very exiting HP48G(X) will be an improved calculator with an HP48-keyboard layout.
My calculator is used daily - specially the software emulator on android: my phone is mostly with me while the calc rest on the desk.
I UPCYCLED an old broken HP48 with an Arduino to simulate a USB keyboard – to make it more comfortable to use the calculator at the desk/with my mobile phone S7 and to work always with latest stack. The keyboard is universal and can be used on several systems: tested so fare under Windows and a little under Android.
I would like to improve this keyboard and need some help.

Please let me know your concerns and ideas.

Best regards
Michael
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