|Re: Hepax Emulation under V41|
Message #2 Posted by Diego Diaz on 14 Sept 2008, 6:14 a.m.,
in response to message #1 by Les Wright
Using HEPAX with V41 is somewhat tricky...
First of all I would recommend you to reinstall your V41 to ensure you have a clean copy of the three HEPAX related .MOD files, namely: hepax.mod hep-mem.mod and hep-2mem.mod, as it may happen that some of them get corrupted while you're playing with the emulation. Save a copy of these files into a different folder and even set them as "read only".
Make sure that the ones you're going to load into V41 emulator are not "read only" as they are writen during normal use.
Paradoxically V41 freezes because it's a perfect replica of the HP-41 behavior.
HEPAX assumes it's plugged into a physical port (usually Port1) thus it tries to start its auto-relocation process from an even page: 8, A, C, of E; and requires RAM in the immediate following odd page to perform the task.
As there is no such physical port in V41 and therefore no real start-up sequence for HP-41 power-up (involfing physical signals in the I/O port interface, HEPAX can only relocate when it's first "plugged-in" (loaded into the configuration window).
Once it has found a suitable page, it remains in that page as long as it remains in such configuration.
When you run HP-41CX emulation the first available page is page 6 and there is where HEPAX will place itself. Regrettably, page six is an even page, thus HEPAX will try to relocate. However it can not find any RAM into page 7, wich is needed to the process... the result is a frozen V41.
To avoid this, you can either use HP-41C/CV emulation, wich makes HEPAX to load into page 5, or load the printer module into HP-41CX emulation, which forces HEPAX to re-locate into page 7.
The good part is that once HEPAX has been allocated into an odd page, it won't try furter relocations, so you can switch your V41 OFF and ON without loosing a bit.
There is a drawback though, the HEPAX file system will not be recovered when a RAM page is cleared. If you want HEPAX file system to be restored, you'll need to re-load the modules again.
Hope this helps.
Best from the Canaries.