The Museum of HP Calculators

HP Forum Archive 15

[ Return to Index | Top of Index ]

Upgrade HP 48G 32K RAM chip
Message #1 Posted by Caribe T on 17 Oct 2005, 8:25 p.m.

I want to upgrade the 32K chip in my 48G. However all the information that I find on the net about doing the upgrades (to 128K, 256K etc) have been done with chips such as the "128K (8bit) static ram chip SMD package (SO32) (HM628128LFP-8 (Hitachi) or KM681000BLG-7L (Samsung))". However it seems that these parts are not readily available - being older model chips, I take it that they have been replaced with newer and larger chips. Can anybody tell me what 'newer' chips I could use that is readily available, that I can just substitute right in place of the chips that are used in the 128K-256K upgrades? Will a "131810 IC,SRAM,628128LP" work (it is 1028K I think). Any help is much appreciated. Thanks

Edited: 17 Oct 2005, 8:29 p.m.

      
Re: Upgrade HP 48G 32K RAM chip
Message #2 Posted by randy on 17 Oct 2005, 10:08 p.m.,
in response to message #1 by Caribe T

On the contrary, they're still around as new. 128K x 8 - M5M51008DFP70HIA0-ND from http://digikey.com $4.50 each, in stock.

Edited: 17 Oct 2005, 10:08 p.m.

            
Re: Upgrade HP 48G 32K RAM chip
Message #3 Posted by Caribe T on 17 Oct 2005, 10:55 p.m.,
in response to message #2 by randy

Thanks very much for that!! Would you happen to know if any on the larger chips can be substituted. For example, to upgrade to 256K requires piggy backing 2 128Ks.....can you put a single 256K on there (if they make them)? If you can, do you know what chip that is? Thanks again

                  
Re: Upgrade HP 48G 32K RAM chip
Message #4 Posted by I, Claudius on 18 Oct 2005, 9:41 a.m.,
in response to message #3 by Caribe T

There are a number of sites listed by www.hpcalc.org on how to upgrade your 48g. I did one with a 128K, it came out all right except I could not get the case to close right again. I had a friend who was an expert machinist drill four very small recessed screw holes at the corners of the case so I could reassemble it tightly. Now I can also take it apart again easily should I wish.

Later I bought a 48g that had been upgraded to a 1 MB memory by Cynox from Germany, outstanding. I'm not sure if they're still doing this, you might want to visit their website. Best of luck.

Edited: 18 Oct 2005, 9:43 a.m.

[ Return to Index | Top of Index ]

Go back to the main exhibit hall