|HP-41CL & NoV-64 (or its siblings)|
Message #1 Posted by Geir Isene on 19 Jan 2012, 2:59 a.m.
I transcended to Nerdvana when I got my first NoV module from Diego, progressed to the Second Circle when I got the CL board and now moving into the Third Circle of Nerdvana with the CL/NoV combo.
I thought I'd share my views on this amazing combination.
First some specs; I have the HP-41CL loaded with the YFNS 2A in page #F, CLUTILS 2G in page #E and CCD OS/X in page #D. This leaves the full 4 blocks of wonderful HEPAX RAM from the NoV-64 module in pages #8-#B as well as the NOV CHAP burned into the ROM of the NoV-64 at page #C. The reason for the latter is that none of the NOV CHAP write-to-h4100 works if the module resides in the CL. These functions work only if the module is inside the NoV-64 module. Also, the NOV CHAP module is essential in the NoV-64 whenever I take the module out and plug it into another HP-41.
The advantage with using the NoV-64 to host the HEPAX are:
- It saves one 4K page as the NoV module gets HEPAX into page #6, something that the CL cannot do.
- The HEPAX RAM is permanent in the NoV - despite MEMORY LOST or flat batteries. To get the same permanency on the CL alone, you will have to write the HEPAX RAM to flash, something that takes a lot of time and is risky.
In addition, the NoV-64 provides a full 4 sets of 4*4K of HEPAX blocks. These blocks are easily swapped by writing the configuration into address h4100 - 10X, where "X" (from 0-3) indicates the block to use. This gives you a full 64K of HEPAX RAM for use - some 32 times the usual program memory on your HP-41. Programs can be saved permanently and run from HEPAX RAM. XM files can be saved, manipulated and used from HEPAX RAM. Calculator memory can be saved and retrieved easily (in a couple of seconds using the NOV CHAP command SAVEN and GETN). Unlike the WRALL from the CLUTILS module on the HP-41CL, the SAVEN doesn't save XM. For that, you have the NOV CHAP program BACKUP.
Switching the blocks of HEPAX RAM is done in less than a second with the functions NX (write the number in X to h4100 - such as 103 to switch to the forth HEPAX 4*4K block) or the direct switching functions N100, N101, N102 and N103. These makes it possible to assign the switching functions to keys for lightning fast block switching. Doing this on the CL alone is "possible" but extremely cumbersome and time consuming - taking minutes to do with permanent HEPAX saves - and it becomes increasingly risky.
You can of course save a copy of your favorite modules to the permanent HEPAX ram in the NoV as well. This makes it easy to have 4 different environments with both a couple of modules and plenty of HEPAX RAM to use for each - and even a memory save for each environment. What joy!
I use the 100 HEPAX block as my default and have the ISENE ROM in page #B while retaining pages #8, #9 and #A as HEPAX RAM with lots of programs, a memory save and a few XM files. My 101 environment contains pure math related programs in 4 HEPAX RAM pages. The 102 environment contains my Role-Playing programs with lots of XM files, while my 103 environment hosts my MCODE project(s). Switching between them is with the blink of the eye.
A simple RESTORE program loads the YFNS to page #F, the CLUTILS to #E and the CCD OS/X to page #D whenever the CL needs new batteries or I manage to lock up the machine with some funny MCODE. Nothing is ever lost with this - I keep an additional backup of RAM and XM on a cassette tape (using the Extended IL ROM) for ultra safety.
With this I have leveled to Nerdvana 3rd Circle.