Ram card on HP48GX



#2

I have a 48GX. I bought a 512KB ram card to expand my memory. Later I stored a library on that card. I put the ram card on slot #1. I can access the library and use the programs in the library, but when I check my available memory it's barly over 90KB. If I take out the ram card and check the memory , it's still 90 KB. Why I don't see the expanded memory. I know that on slot # 1 the calculater sees only the first 128KB and cannot use the rest, but no matter if I put the card on #1 or #2 slot,the memory is always 90KB.
One other ? I have is that I get error massege now when I want to add another library to that ram card.


#3

Look up the manual.

I think you are getting port meory confused with merged memory. But you cannot merge anything more than a 128 kb card, and so the 512 will always be port memory.

Merged memory takes the card and "merges" it with onboard system memory. At that point, it is no longer port memry--and removing the card is like taking part of the brain out.

**If you put your 512 kb card into slot 2* it will show up as port 1, 2, 3, etc. Without the card, you only have port 0.

Putting a card into slot 1 does not automatically merge it. You have to ask for that. This is on purpose--for some configs, a person doesn't need extra system memory--but does need storage. The merge feature enables the user to configure this aspect.

Edited: 22 Mar 2006, 10:04 p.m.


#4

I forgot to mention orginally (editd in now) that you can used the 412 card--but only in slot 2. You do not need to have a card in slot 1 in order to use a card in slot 2. You just don't have the merge1 available.

#5

Quote:
Look up the manual.


Thank you for your comment. As you and Han have recommended, I took the 512 ram card from slot 1 and put it in slot 2. When I turn it on it gives me Warning "Invalid Card Data" but it works after that ,I checked my library on that card, everything is accessable. Now I have downloaded another library from Hpcalc.org, based on instruction i have to put the # of port on stack and install it on that port which is port 2 now, but it gives me STO Error " Bad Argument Type". How can I check on a ram card what available memory is? I personally don't think it's not enough memory on that card, bacause the library sitting on my computer before installation was 80KB.
Another question:
I have bought a library on a memory card, I don't know what the size of the card is. I can access the card with right shift and Library key, do you think it's OK to leave this one on slot 1?

Edited: 23 Mar 2006, 1:28 a.m.


#6

To clarify, allow me to make a few definitions.

Card slot: the physical slots into which a ROM or RAM card is inserted. The HP48GX has two such slots. Card slot 1 can only recognize 128KB of RAM. Inserting a RAM card with a larger capacity could possibly damage the card and/or card slot.

Port: this is an HP48 object, very much like a library or variable or program are all HP48 objects. The HP48GX can have up to 33 ports (0 through 32). Port 0 is the same as user memory. Port 1 is the port associated to card slot 1. Ports 2, 3, 4, ... and higher are associated with card slot 2. Each port has a maximum size of 128KB.

Memory Bank: a subsection of memory. As an example, your 512KB RAM card consists of 4 banks of memory, each of size 128KB. Each recognized bank of RAM creates a port. Card slot 1 only recognizes one bank; card slot 2 recognizes all banks.

Merged Memory: user memory combined with the memory in card slot 1. You can have a maximum of 256KB memory by using the MERGE1 command with a 128KB RAM card inserted into card slot 1. (Remember that card slot 1 only sees 128KB of RAM.) This plus the default 128KB of user memory produces 256KB of merged memory. Card slot 2 cannot be merged.

There are two types of 512KB RAM cards: The 1x512KB type which, when inserted into card slot 2, produces Ports 2, 3, 4, and 5; the 4x128KB type is, practically speaking, four 128KB RAM cards in one. On the 4x128KB card, there is a switch that allows you to manually "change" to one of the four virtual RAM cards.

#7

Quote:

I took the 512 ram card from slot 1 and put it in slot 2. When I turn it on it gives me Warning "Invalid Card Data" but it works after that


That error is due to the fact that 1 or more of the banks on your card are uninitialized. That makes sense if you were using it in port 1. Run PINIT and that error should go away, and you should also be able to use the rest of your memory in slot 2. (Ports 2, 3, 4 and 5.)

Quote:

I checked my library on that card, everything is accessable. Now I have downloaded another library from Hpcalc.org, based on instruction i have to put the # of port on stack and install it on that port which is port 2 now, but it gives me STO Error " Bad Argument Type". How can I check on a ram card what available memory is? I personally don't think it's not enough memory on that card, bacause the library sitting on my computer before installation was 80KB.


The procedure is 1) put the library on the stack, 2) enter the port number, for example 2, 3) Press the STO key. That error implies that the object on the stack is not the correct type. On the stack, the library should look like 'Library nnn abcd..' where 'nnn'is the library number and 'abcde..' is its text description. So you should have that on stack level 2 and the port number in level 1 before pressing 'STO'.

To see what is in a particular port. Put the port number on the stack and execute 'PVARS'. This will return a list of library addresses in level 2 and the free memory in the port on level 1.


Quote:
Another question:
I have bought a library on a memory card, I don't know what the size of the card is. I can access the card with right shift and Library key, do you think it's OK to leave this one on slot 1?


Odds are it is a 128K card that will do just fine in slot 1. What is the card?

Regards,
Howard

Edited: 23 Mar 2006, 2:50 a.m.


#8

Quote:

Odds are it is a 128K card that will do just fine in slot 1. What is the card?

Regards,
Howard


Regarding the card in slot 1, it's a collection of land surveying equations programmed into a plug-in library card. When I used the PVARS command following was on stack 2:
:1:995.0000:1:991.000:1:989.000:1:997.000:1:987.000:1:985.000:1:1001.0000:1:993.0000:1:983.0000:1:981
On Stack 1 was showing "ROM".
I have a question, I had a library on that 512 card, now I finally managed to add the other library, old one on port 4 and new one on port 2, but when I go to left shift "alfa" and hit CST I only can access the new library. What happend to the old library sitting on port 4? It is still there, because when I check with PVARS on stack 2 I have :4:1013.000 and on stack one I have 48,369.000 which shows there is some memory taken.

#9

OK, so that ROM card is probably quite happy sitting i slot 1.

Quote:
.. but when I go to left shift "alfa" and hit CST ..

Left-shift-alpha gives you user mode. User mode CST doesn't produce anything on my machine. So someone is defining a custom menu on the CST key for you. (Perhaps more experienced 48G folks can elaborate.) The way you get to libraries generically is to press right-shift-2 (LIBRARY). This brings up a menu with softkeys for each installed library. (Left-shift 2 gets you a menu of useful commands for use with libraries, including PVARS.)

Regards,
Howard

Edited: 23 Mar 2006, 5:42 p.m.


#10

Quote:
OK, so that ROM card is probably quite happy sitting i slot 1.


Left-shift-alpha gives you user mode. User mode CST doesn't produce anything on my machine. So someone is defining a custom menu on the CST key for you. (Perhaps more experienced 48G folks can elaborate.) The way you get to libraries generically is to press right-shift-2 (LIBRARY). This brings up a menu with softkeys for each installed library. (Left-shift 2 gets you a menu of useful commands for use with libraries, including PVARS.)

Regards,
Howard


Thanks Howard,
Your advise helped me alot. As you said I can access libraries with right shift LIBRARY.
#11

In order to expand user memory on an HP48GX, you must use the MERGE1 command with a 128KB RAM card in card slot one. This "merges" the memory in the RAM card with the default 128KB user memory.

I do not recommend using a 512KB RAM card in slot one. While the HP may see one of the banks on the 512KB RAM card, it is not clear that it is always the same bank. In fact, there are various pins in card slot one which correspond to the LCD signals. If these are read as input for the 512KB RAM chip, you may end up corrupting the data on your RAM card. Also, if you merge memory with a 512KB RAM card in slot one, the HP may use the wrong bank the next time you turn on the calculator or re-insert the card.

I recommend re-reading your user's manual and try to abide by the rules set out by HP regarding card slots.


Best of luck,
Han


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