Memory

Viewing Memory

There are two mini-memory areas on the info panel. You can view memory in Hex, (normal 7-Bit) ASCII, or Apple (8-Bit) TEXT format.

Control characters are shown in yellow. The Apple uses something called 8-Bit (High-Bit) ASCII, in which the first 128 characters (normal ASCII) are also mapped onto the last 128 characters, but with a different background. (Technically, the first 64 characters are drawn inverse, the next 64 characters flashing, and the last 128 normally.) Some programs will store text in this extended Apple format, where a High-Bit character can be used as a flag to represent an end of word.

Here is a summary:

Normal ASCII (non-control characters) will show up in cyan; High-Bit text in white.
Apple TEXT (normal ASCII) will also display with an inverse background; High-Bit with a normal background.

Command	Effect
M1	Show full address prefix for mini-memory 1. (See Notes)
M2	Show full address prefix for mini-memory 2. (See Notes)
M1 ####	View mini-memory 1 in Hex at the Address
M2 ####	View mini-memory 2 in Hex at the Address
MA1 ####	View mini-memory 1 in ASCII at the Address
MA2 ####	View mini-memory 2 in ASCII at the Address
MT1 ####	View mini-memory 1 in “Apple Text” at the Address
MT2 ####	View mini-memory 1 in “Apple Text” at the Address
D ####	Alias for M1

Examples:

Input	Effect
M1 D000	View current memory at $D000, which could be ROM or RAM.
M1 L1/D000	View current Language Card memory (4K bank 1) at $D000. (See Notes)
M1 01/L2/D000	View Auxiliary Language Card memory (4K bank 2) at $D000. (See Notes)
M1 S3/7/L1/D800	View slot 3's Saturn card's 16K bank 7, 4K bank 1 at $D800. (See Notes)
MA1 ROM/D0D0	View Applesoft Tokens (Low ASCII cyan, High ASCII white). (See Notes)
MT2 ROM/FF0A	View Apple message displayed when booted, showing Apple Model. (See Notes)
M1 S4/MB	View slot 4's Mockingboard/Phasor (unit A): 6522 & AY-3-891x's registers. (See Mockingboard notes)
M1 S4/AYB	View slot 4's Phasor (unit B): both AY-3-891x's registers. (See Mockingboard notes)
DATA	Switch to the Data Window to view memory. Most scrolling keys work.
CODE	Switch to the Code Window to view the disassembler.

Notes:

For more information about address prefixes, see the page on Breakpoints.
In the image at the top, prefixing the address ("D000") are the bank number (white "01") and LC bank (green "2").

Mockingboard notes:

Mockingboard/Phasor: m<1|2> MB[A|B]. Show 6522 & AY-3-891x's registers for either sub-unit A or B
- The 6522 TIMER1 (regs 4 & 5) and TIMER2 (regs 6 & 7) registers are white when active.
- The selected AY-3-891x register is shown in white.
- The AY-3-891x modes are shown: --(inactive), LA(latch), WR(write) and RD(read).
Phasor: m<1|2> AY[A|B]. Show both AY-3-891x's registers for either sub-unit A or B.

Example showing 6522 active TIMER1 ($03D8) and active AY reg-0 ($42) during a write (WR).

Zero-page Watches

Add a zero-page watch at the indirect address (nn).

Command	Effect
ZPA (or ZP) nn	Add/Update address to next zero page pointer
ZPA (or ZP) # nn	Add/Update address to specific zero page pointer
ZPC #	Clear (remove) zero page pointer
ZPD #	Disable zero page pointer - it is still in the list, just not active
ZPE #	(Re)Enable disabled zero page pointer
ZPL	List all zero page pointers

Memory Watches

Add a 16-bit memory watch at the 16-bit address nnnn.
NB. For 'WA # v': specifying 'v' instead of an address will watch the video scanner.

Command	Effect
WA (or W) nnnn\|symbol	Add/Update address or symbol to next watch
WA (or W) # nnnn\|symbol\|v	Add/Update address or symbol to specific watch
WC #	Clear (remove) watch
WD #	Disable specific watch - it is still in the list, just not active
WE #	(Re)Enable disabled watch
WL	List all watches

Searching Memory

You can search memory for hex values. Wildcard support is also supported via the '?' wildcard operator, including nibble searching. A single '?' by itself, means match one byte of any value. A hex value with the high nibble or low nibble of '?' will mask off the corresponding nibble. (At the moment there is no way to refer to the list of results. A future version will support _# to reference search result's addresses.)

Searching memory for text is forthcoming in a future version of the debugger.

Command	Effect
SH #,len byte1 …	Search memory for 8-bit hex value(s).
SH #,len word1 …	Search memory for 16-bit value(s).

Examples:

Input	Effect
SH 800,8000 C030	Search memory for speaker access.
SH 800,8000 AD ? C0	Search memory for “ LDA $C0xx”.
SH 800,8000 3? C0	Search memory for speaker access $C03x.
SH 800,8000 ?1 C0	Search memory for soft-switch $C0x1.
L _1	Disassemble from search result #1 address. Note: Not yet implemented!

Changing Memory

To change the Apple's memory, the classic "Apple Monitor" command to enter memory is recognized, as well as the "normal" debugger comamnd.

Command	Effect
####:byte1 …	Classic "Apple Monitor" command to enter byte(s). Alias for E.
E addr byte1 …	Set memory to the 8-Bit (byte) value(s).
EB symbol ####	Alias for E.
E8 symbol ####	Alias for E.
EW symbol ####	Set memory (at the symbol Address) to the 16-Bit (word) Value(s).
E16 symbol ####	Alias for EW.
NOP	Writes an “NOP” opcode (EA) at the current Program Counter (PC)
ZAP	Alias for NOP.

Examples:

Input	Effect
300:60	Same as Applesoft Poke 768,96