getting back onto the TDS Survey GX card
Andy
I recently purchased an hp 48gx with a survey gx card and 512 ram card
on ebay, when i first turned it on i was already on the survey card
and i scrolled through the menus easily. I exited out of the survey
card and now i am having troubles getting back onto it. When i type
TDS48 and hit enter i get the message " Installing Library....Failed.
For installing, insert program card in port 2". Should i install the
survey card in port 2 when it clearly say only to install it in port
1? I have already tried taking out the cards and batteries and left
over night then reinserting them and i still get the same message. I'm
not at all familiar with this calculator, any advise would be greatly
appreiciated. Thanks
Rgds,
Andy
rs1n
1. Turn off HP48GX; place the ROM card in card slot 2
2. Turn on HP48GX and then run TDS48.
3. Turn off HP48GX and now place ROM card in card slot 1
4: Turn on HP48GX and you should be good to go.
Long answer:
The calculator can only handle up to 128KB per physical card slot. So
a 512KB RAM card can only be viewed 128KB at a time (i.e. via ports 2
through 5) while sitting in card slot 2. Viewing one block means ther
others are "covered." Each 128KB block must be bank-switched (for card
slot 2). In card slot 1, only one block of 128KB of memory (which one
will be dependent on how the card was built). To put it simply,
accessing programs or commands from card slot 1 does not require
copying said programs to user memory prior to executing the code,
unlike with card slot 2.
Most ROM cards are only 128KB in size and some are coded with absolute
addresses for speed. Since there is no bank-switching for card slot 1
-- at least not in the original operating system -- this is why it is
recommended that you leave your ROM cards in slot 1.
This TDS ROM card is likely larger than 128KB (perhaps 256KB -- two
blocks of 128KB?). Installing it in card slot 2 allows you to access
commands that reside in either block of the two 128KB blocks of ROM.
Perhaps TDS48 is a command that requires accessing routines from the
"other" block, and this is why you must first place it into card slot
2. My guess is that TDS48 does some initialization routines that
reside on the "other" block of 128KB of ROM, and that the main portion
of the software you use is on the "default" block of 128KB of ROM when
placed into card slot 1. This is also a security feature that would
prevent piracy (to some degree), since you would need a RAM card
larger than 128KB to copy the ROM card onto.
Hope that long-winded answer didn't cause more confusion :-)
Andy
Thanks you very much for the explanation, my problem is solved!
Rgds,
Andy