41CL MMU Backup

[Ángel Martin]

(05-30-2020 03:45 PM)Ángel Martin Wrote:  So never mind, I guess we're back to having to remap the library#4 after YFWR (in the YFNX) has terminated....

Ok but it's not too difficult to get it fixed after the fact - just adding three instructions to YRALL remapping Library#4 to page#4 does the trick. I chose PPLUG because it requires shorter text in ALPHA: ("4LIB", 4, PPLUG 7 bytes instead of "804040-8120" YPOKE 12 bytes)


YWALL can be optimized using a subroutine, to the final form shown below - also checking on the low battery condition before doing any flash writings:

Code:

1    LBL "YWALL"
2    "1FE"
3    XEQ 00
4    "1FF"
5    FS? 01
6    XEQ 00
7    GTO 92
8    LBL 00
9    ASTO T
10    >"000"
11    AVIEW
12    FC? 49
13    YFERASE
14    "800>"
15    ARCL T
16    AVIEW
17    FC? 49
18    YFWR
19    RTN
20    LBL "YRALL"
21    "1FE>800"
22    AVIEW
23    YMCPY
24    "1FF>804"
25    AVIEW
26    FS? 01
27    YMCPY
28    "4LIB"
29    4
30    PPLUG
31    LBL 02
32    "DONE"
33    END

The role of user flag 01 is to choose if only the 801 block (cF1 clear) or also the MMU registers (F1 set) will be backed up.
In the POWER Extreme module this is managed by the string in ALPHA as explained in the manual:

"OK" means only the 800 block
"OKALL" means both 800 and 804 blocks