Author Topic: 83+/84+ Free Ram Areas (Read 29711 times)

thepenguin77 · « **on:** June 12, 2012, 11:47:39 pm »

Hey everybody, Sorunome here. I converted this table into a more machine-readable format and made it way easier to search by address or by ID, so e.g. when searching for 8005 (or $8005 or 0x8005) it'll jump to appData.
You can find it here: https://www.omnimaga.org/index.php?page=ram
here is some more information as to what all that search supports

Spoiler For Old Post:

persst collat addr name size what destroys it how you should fix it what it breaks

***** ***** 8000 appData 256 v APD (OFFSCRPT) -----
*** ***** 8100 ramCode 119 | flash activities -----
***** ***** 8177 smallEditCol 185 | ---- -----
***** **** 8230 baseAppBrTab 33 | ---- bcall(_fillBasePageTable) multipage apps on 83+
***** ***** 8251 bootTemp 8 | receiving OS -----
***** ***** 8259 MD5Stuff 74 | MD5 calculations -----
**** ***** 82A3 appSearchPage 2 | OS general app routines -----
**** ***** 82A5 tempSwapArea L4 232 | archive stuff -----
**** ***** 838D appID 5 | OS general app routines -----
**** ***** 8392 arcPageStuff 3 | most archive operations -----
**** ***** 8395 16 | ??? -----
* ***** 83A5 MD5Buffer 12 | Axe-subroutine arguments -----
** ***** 83B1 MD5Buffer 30 | Axe-Archived variable pointers -----
** *** 83CF MD5Buffer 2 | Axe-random seed -----
*** ***** 83D1 MD5Buffer 8 | Axe-sprite rotation/flipping and hex printing -----
**** ***** 83D9 MD5Buffer 12 | Axe-axiom variables -----
***** ***** 83E5 6 | ??? -----
*** ***** 83EB Abackup 1 | flash operations, app bcalls, and other? -----
**** ***** 83EC 2 | ??? -----
**** ***** 83EE arcInfo 68 | link routines and other? -----
**** ***** 8432 appInfo 13 ^ OS general app routines -----
843F 1087

**** ***** 8452 prevDData 8 V ??? zero
* ***** 845A lFont_record 8 | large font -----
* ***** 8462 sFont_record 8 | small font -----
**** **** 846A tokVarPtr 4 | ??? zero
**** ***** 846E indicMem 10 | run indicator -----
* ***** 8478 OP1 11 | Axe-AppVars, float{}, Ans, Text >Dec -----
** ***** 8483 OP2 11 | Axe-float{}, Ans, Text >Dec -----
*** ***** 848E OP3 11 | Text > Tok -----
*** ***** 8499 OP4-OP6 38 | random OS routines -----
**** ***** 84BF progToEdit 8 | running apps, editing progs -----
**** ***** 84C7 nameBuff 11 | typing a name -----
**** ***** 84D2 equ_edit_save 1 | ??? opening an editor? -----
**** ***** 84D3 iMathPtrs 10 | editing anything -----
**** ***** 84DD stuff 14 | ??? probably editing? zero
** ***** 84EB asm_pointers 8 | moving user memory -----
***** ***** 84F3 asm_ram 21 | ----- -----
**** **** 8508 textShadow L5 128 | ----- bcall(_clrTxtShd)
**** **** 8588 textShadPtrs 5 | ----- bcall(_clrTxtShd)
**** ** 858D cxVectors 25 | ----- manual restore changing apps (quitting)
**** ***** 85A6 4 | ----- -----
**** ***** 85AA monQueue 18 | ??? -----
*** *** 85BC onSP 2 | ----- manual restore homescreen errors
**** ***** 85BE promptStuff 18 | ??? -----
**** ***** 85D0 varType 12 | ----- -----
**** *** 85DC menuStuff 7 | ----- zero
**** *** 85E3 menuFlagBackups 4 | ----- zero
**** ***** 85E7 progCurrent 120 | ----- -----
***** ***** 865F linkStuff 120 | linking -----
* **** 86D7 penCol 2 | small font, OS drawing zero works
**** **** 86D9 rclQueuePtrs 4 | ----- -----
*** *** 86DD errNo 1 | OS errors (like appvar stuff) zero
*** *** 86DE errSP 2 | OS errors manual restore
*** *** 86E0 errOffset 2 | OS errors zero
***** ***** 86E2 10 | -----
***** ***** 86EC saveSScreen L1 714 | APD -----
** ***** 89B6 saveSScreen L1 54 ^ Axe-A-Theta -----
89EC 1434

***** ***** 8A36 4 V ----- -----
***** ***** 8A3A statVars L2 531 | ----- bcall(_delRes)
***** ***** 8C4D infVars 202 | ----- zero
***** *** 8D17 curGStyle 1 | ----- zero
***** **** 8D18 curGY 137 | ----- zero
***** ** 8DA1 graphStuff 6 | ----- manual backup graphing
***** **** 8DA7 entryStackStuff 133 | ----- manual backup entry stack (2nd entry)
***** ***** 8E2C 59 | ??? -----
***** **** 8E67 graphVariables 494 | ----- bcall(_grReset) graphing variables
***** **** 9055 financeVariables 126 | ----- bcall(_zeroFinanceVars) finance variables
***** ***** 90D3 smallEditRam 108 | ----- -----
***** **** 913F moreGraphVars 157 | ----- bcall(_grReset) graphing variables
***** **** 91DC tableStuff 294 | ----- zero
***** **** 9302 entryStackStuff 5 | ----- manual restore entry stack (2nd entry)
***** ***** 9307 57 | BASIC menus -----
** ***** 9340 plotSScreen L6 768 | most screen activities -----
***** **** 9640 randomSeeds 18 | ----- bcall(_randInit)
***** **** 9652 parsingPtrs 28 | ----- manual restore quittting
***** *** 966E cmdShadow 128 | ----- bcall(_clrTxtShd) then bcall(_saveCmdShadow) MirageOS
LnReg and manual restore for MirageOS
***** **** 96EE cmdShadowPtrs 6 | ----- bcall(_clrTxtShd) then bcall(_saveSmdShadow)
**** ***** 96F4 editPtrs 8 | opening edit buffer -----
***** **** 96FC listEditPtrs 121 | ----- zero
***** **** 9775 graphTypes 48 | ----- zero
***** * 97A5 windowStuff 11 | ----- manual restore small and large text
**** ***** 97B0 formatStuff 92 | displaying OS formatted strings -----
***** ***** 980C equationStuff 9 | ??? evaluating an equation? zero
**** **** 9815 11 | ??? deleting stuff? zero
** * 9820 stackPointers 20 | user mem operations manual restore don't touch user mem (appvars)
**** ***** 9834 pagedStuff 8 | archive reading -----
**** ***** 983C 43 | menus zero
**** ***** 9867 flashTemp 9 | reading flash -----
**** ***** 9870 appRawKeyHandle 2 | ??? -----
***** ***** 9872 appBakUpScrn L3 768 ^ ----- -----
9B72 4412

***** **** 9C06 baseAppBrTab2 106 V usb stuff bcall(_fillBasePageTable) multi page apps on 83+SE
***** **** 9C70 usbStuff 62 | usb stuff -----
*** ***** 9CAE SESpeed 1 | this might get randomly written to -----
***** ***** 9CAF 182 | ??? -----
**** ***** 9D65 localTokStr 17 | used by localization apps -----
**** ***** 9D76 keyToStr 18 | ??? -----
***** ***** 9D88 sEdMonSp 2 | small edit SP -----
***** ***** 9D8A bpSave 11 ^ usb stuff -----
9D95 399

Persistence:
***** barring obscure situations, this memory won't be touched by outside forces
**** some avoidable practices will overwrite this memory
*** normal operation may occasionally overwrite this memory
** this memory location is not stable by any means, though, it's still memory
* this is hardly memory, it's only listed because it was in the way

Collateral damage:
***** changing this memory has absolutely no effect on anything
**** there are some situations where changing this has an effect, though, you probably won't run into them
*** this makes some rather rare events fail, but it could happen
** this makes some common tasks fail
* honestly, the calculator basically crashed

bcalls:
bcall(_clrTxtShd) Asm(EF4C45)
bcall(_delRes) Asm(EF204A)
bcall(_fillBasePageTable) Asm(EF1150)
bcall(_grReset) Asm(EF3148)
bcall(_randInit) Asm(EF7F4B)
bcall(_saveCmdShadow) Asm(EF7345)
bcall(_zeroFinanceVars) Asm(EF2B51)
[/size]
[/font]
[/td][/tr]
[tr][td]

[/td][/tr]
[/table]

The collateral damage number is only correct if you follow my recommendations for cleanup. If you don't, then things might go very bad. What it breaks is what won't work when you are using that memory, it will work after you are done.

And when you clean up, I recommend you first zero all the memory you used, copy back the manual backup locations, and then run all the necessary bcalls.

Lastly, if you see any changes that need to be made to the list (like anything), be sure to tell me.

Be sure to thank shmibs for hacking the width of this page.

Runer112 · « **Reply #1 on:** June 13, 2012, 01:38:26 am »

This is a pretty awesome list. Already bookmarked your post.

I have two questions:

What does the *breaks mirage* note mean for cmdShadow, and are we sure there's no way to fix this?
You mention that the "collateral damage number is only correct if you follow my recommendations for cleanup." Does this mean that if I use baseAppBrTab, even with your recommended cleanup, I'll break multi-page apps on 83+es? That doesn't sound good.

Then, suggestions:

Do you want to add specific information about what Axe commands destroy areas of RAM or will be broken if the user destroys them?
MD5Buffer could be in the list, as at least parts of it are non-essential. Here's how Axe uses it in order from the end of MD5Buffer to the start (because the order of use is mostly most common up front, least common at the back):
- 83D9 12 bytes Axiom variables
- 83D1 8 bytes Sprite rotation/flipping and hex printing
- 83CF 2 bytes Random seed
- 83B1 30 bytes Archived variable pointers (files)
- 83A5 12 bytes Subroutine arguments
Should OP1 and possibly OP2 have slightly lower persistence ratings? A fairly decent number of Axe commands go through these, especially OP1.
I think I could supply decently small substitutes in native Axe for a few of the cleanup B_CALLs, if you wanted that. I know some people like their Axe programs to be pure Axe.

Other than these nitpickings of mine, awesome.

aeTIos · « **Reply #2 on:** June 13, 2012, 03:46:33 am »

Wow, great list. This should definitely be stickied (or is it already?)

kindermoumoute · « **Reply #3 on:** June 13, 2012, 05:26:47 am »

Thaaanks !

EDIT : can I use it in my Axe tutorial ?

shmibs · « **Reply #4 on:** June 13, 2012, 09:49:08 am »

axe vars are stored in SaveSScreen, not appBackUpScreen.
the does look rather useful. =D

thepenguin77 · « **Reply #5 on:** June 13, 2012, 01:12:33 pm »

Quote from: kindermoumoute on June 13, 2012, 05:26:47 am

EDIT : can I use it in my Axe tutorial ?

Sure, though, you might want to wait a few days so that all of the errors have been fixed.

aeTIos · « **Reply #6 on:** June 13, 2012, 01:23:16 pm »

Um, since you updated the font the table is broken on small screens. (read: my screen)

FloppusMaximus · « **Reply #7 on:** June 13, 2012, 03:31:24 pm »

Runer112: cmdShadow is used for MirageOS internal storage. If you overwrite that area, it will break both the MirageOS GUI and some of the MirageOS library routines. The same is true of some parts of statVars, I don't remember which exactly. And you can expect the same is true of other shells.

The other thing about cmdShadow is that it is used for Ion's program loader (and, of course, the Ion libraries) so you absolutely must not overwrite that area in an Ion program.

Also, thepenguin77, you didn't mention that appData can be overwritten when APD occurs.

TIfanx1999 · « **Reply #8 on:** June 13, 2012, 03:57:28 pm »

Moved and stickied.

aeTIos · « **Reply #9 on:** June 13, 2012, 06:53:32 pm »

Umm, I think this is not only ASM. This was also intended for use with Axe.

Runer112 · « **Reply #10 on:** August 18, 2013, 11:45:27 pm »

I found out that parsingPtrs is not safe the hard way. It took me a good hour or so to debug that overwriting basic_start, nextParseByte, and possibly basic_end causes errors to be thrown when the program exits, despite the program not being a BASIC program.

ZippyDee · « **Reply #11 on:** January 05, 2014, 06:33:17 pm »

Just for clarification, are the large spans of unlabeled RAM such as at $843F or $89EC all untouchable? Or just unknown?

thepenguin77 · « **Reply #12 on:** January 05, 2014, 08:18:03 pm »

If it's not labelled, it probably has a 1 star in both categories. Don't even try to mess with those areas unless you are going to restore them afterwards and aren't going to use any bcalls.

Xeda112358 · « **Reply #13 on:** January 10, 2014, 09:34:28 am »

Quote from: ZippyDee on January 05, 2014, 06:33:17 pm

Just for clarification, are the large spans of unlabeled RAM such as at $843F or $89EC all untouchable? Or just unknown?

I believe 843Fh is where the OS interrupt handles key presses and such. If I remember correctly, 843Fh holds the current key press, 8445h holds the last registered key press, and the other in between are counters. Specifically, 8442h is used for repeating keys, starting with a value of 50, counting down to zero. If it reaches 0 and it is a repeating key (arrows or [del]) it repeats the key press, and resets the counter to 10. This is why the initial delay is longer after pressing arrows and such. I read these RAM areas because it is much faster than a silly bcall

You do need interrupts enabled, though.

EDIT: Actually, rereading your post, ZippyDee, I think you read the values like "1087" and "1434" as the size of the gap. instead, if you subtract 8000h from the address and convert to decimal, you will see these are just the offset into RAM

c4ooo · « **Reply #14 on:** March 07, 2015, 04:21:46 pm »

What exactly are "lFont_record" and "sFont_record"?

Author Topic: 83+/84+ Free Ram Areas (Read 29711 times)

thepenguin77

83+/84+ Free Ram Areas

Runer112

Re: 83+/84+ Free Ram Areas

aeTIos

Re: 83+/84+ Free Ram Areas

kindermoumoute

Re: 83+/84+ Free Ram Areas

shmibs

Re: 83+/84+ Free Ram Areas

thepenguin77

Re: 83+/84+ Free Ram Areas

aeTIos

Re: 83+/84+ Free Ram Areas

FloppusMaximus

Re: 83+/84+ Free Ram Areas

TIfanx1999

Re: 83+/84+ Free Ram Areas

aeTIos

Re: 83+/84+ Free Ram Areas

Runer112

Re: 83+/84+ Free Ram Areas

ZippyDee

Re: 83+/84+ Free Ram Areas

thepenguin77

Re: 83+/84+ Free Ram Areas

Xeda112358

Re: 83+/84+ Free Ram Areas

c4ooo

Re: 83+/84+ Free Ram Areas