Re: HP41CY - Replacing the internal +3v lithium cell Message #5 Posted by Christoph Klug on 28 Feb 2006, 3:31 a.m., in response to message #4 by Juergen Keller
Dear HP41 RAM-Box enthusiasts,
it seems to be easy to reload the operating system of non bankswitched RAM-box systems = 32KByte RAM-Box systems. I done this several times : In this case you are able to install an ERAMCO os to an W&W RAM-Box or a W&W os to an ERAMCO RAM-Box, depending which os you prefer or which os size you like to store inside your RAM-box (4KByte or 8KByte). In any case this solution will work.
First you have to clear the RAM pages of the RAM-box, for example by using the ZENROM. When the HP41 is able to switch on correctly including the RAM-Box, the clear process is finished. For reloading you only need the CCD-D from Raymond, stored inside an ZEPROM or Clonix. Use the commands SAVERAM and GETRAM and store the needed os to IL-CASS-Drive. Than switch the internal protect switch of the RAM-Box to the write position, and save the os to the RAM-Box page. Now place the switch back to the protect position.
For W&W RAM-Box solutions place the os to page 8, for ERAMCO RAM-Box solutions place the os to page E + F = 14 + 15.
Much more complex is the os reload process of bankswitched RAM-Box systems which includes 64KByte = two banks (W&W and ERAMCO) or 128KByte = four banks (ERAMCO). For this systems we are looking for a working solution....
Best regards - Christoph Klug
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