Re: [41CL] Rescue from 'Lost Y Functions' Message #8 Posted by Dan Grelinger on 27 Feb 2013, 4:25 p.m., in response to message #7 by Dan Grelinger
Monte gave me a new copy of the customized Time ROM. This version has the 'slow down' instruction bits set only where necessary, and still includes the new 'Y functions restore' (YRES) function.
My initial testing has verified that the Time functions that did not behave well when Turbo was enabled (ALMCAT [CAT 5], Notification Alarms, and Past Due Alarm notifications) now work fine. I've done the testing by using the MAPEN functionality to map the new Time rom image from RAM, and I am close to the point of flashing the Time Rom page in the protected sector at flash memory page 006 to complete my testing.
This new version of the Time ROM has two benefits over the original one shipped with the 41CL (the original was a duplicate of the HP-41CX Time functions page, with all instructions tagged to run at 1X speed).
1. Only those instructions that need to run at '1X' speed are flagged for 1X execution. This enables most of the Time functions to take advantage of the selected Turbo mode. I have not noticed any difference during keyboard execution, but in theory, programs with Time functions in them will benefit when Turbo is enabled.
2. The insertion of a new function 'YRES' that works just like 'MMUDIS', but is available even when no CL Extra Functions are currently mapped to memory. Normally, recovery from this state requires the batteries to be removed (for > 11 seconds on my unit) in order for the MMU enabled bit to be reset and YFNZ functions be made available in page 7 again. Now, as the Time functions are always available (assuming no advanced OS remapping) it is possible to recover from a 'lost Y functions' with a single command.
The Time functions headers are now '-TIME 3A' and '-CL TIME', which are visual clues that the adjusted Time Rom is installed.
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