83Plus:Ports:07 - Revision history

Dr. D'nar at 04:31, 20 February 2013

2013-02-20T04:31:04Z

Dr. D'nar: TI-84+CSE

2013-02-20T04:13:38Z

TI-84+CSE

FloppusMaximus: /* Example */

2005-03-30T17:54:10Z

‎Example

FloppusMaximus: /* Comments */

2005-03-30T17:53:06Z

‎Comments

FloppusMaximus at 05:17, 30 March 2005

2005-03-30T05:17:57Z

Dan Englender: Added categories (Don't like name, see discussion on port 5)

2005-03-28T17:48:36Z

Added categories (Don't like name, see discussion on port 5)

Dan Englender: Redundancy and normal mapping

2005-03-28T03:37:42Z

Redundancy and normal mapping

AndyJ: /* Example */ used the stack to store the old page

2005-03-28T03:33:29Z

‎Example: used the stack to store the old page

Aquanight at 03:32, 28 March 2005

2005-03-28T03:32:02Z

New page

== Synopsis ==
'''Port Number:''' 07h

'''Function:''' Flash/RAM Memory Paging (Bank B)

This port controls what page is swapped into Memory Bank B (see comments).

=== Read Values ===
* The current port mapped to Memory Bank B (see comments).
** 83+ Basic: If a RAM page is swapped in, the port reads the RAM page number with bit 6 set. If a ROM page is swapped in, the port reads the ROM page number with bit 6 reset.
** 83+ Silver, any 84+: If a RAM page is swapped in, the port reads the RAM page number with bit 7 set. If a ROM page is swapped in, the port reads the ROM page number with bit 7 reset.

=== Write Values ===
* The page number to swap into Memory Bank B (see comments).
** 83+ Basic: If bit 6 is set, bit 0 will choose between the two RAM pages (40h or 41h). If bit 6 is 0, bits 0~4 select a page from ROM (00h through 1Fh).
** 83+ SE, 84+ (any): If bit 7 is set, bits 0~2 will choose any of the 8 RAM pages (80h through 87h). If bit 7 is 0, bits 0~5 on the 84+ Basic, or bits 0~6 on either SE will select a page from ROM (00h through 3Fh or 7Fh).

== Comments ==
The behavior of this port changes in different memory map modes. See [[83Plus:Ports:04|Port 04h]] for details about memory map modes.

Unless you're really clever, the calculator will crash if you return to TIOS with anything other than RAM Page 1 (41h on 83+ Basic, 81h on everything else) swapped in.

== Example ==
<nowiki>push af
in a,(7)
ld (oldMemPage),a
ld a,1
out (7),a
; do stuff that needs page 1 swapped in
ld a,(oldMemPage)
out (7),a
pop af</nowiki>

← Older revision		Revision as of 04:31, 20 February 2013
Line 6:		Line 6:

	This port controls what page is swapped into Memory Bank B (see comments). On the TI-84+CSE, port [[83Plus:Ports:0F\|0F]] also affects MemB.		This port controls what page is swapped into Memory Bank B (see comments). On the TI-84+CSE, port [[83Plus:Ports:0F\|0F]] also affects MemB.
		+
		+	See also [[83Plus:Memory Mapping\|Memory Mapping]].

	=== Read Values ===		=== Read Values ===

@@ Line 20: / Line 20: @@
 Under normal circumstanes this port controls the page mapped to 8000h.  The behavior of this port changes in different memory map modes. See [[83Plus:Ports:04|Port 04h]] for details about memory map modes.
-Unless you're really clever, the calculator will crash if you return to TIOS with anything other than RAM Page 1 (41h on 83+ Basic, 81h on everything else) swapped in.
+Unless you're really clever, the calculator will crash if you return to TIOS, call most system routines, or even allow an interrupt to occur with anything other than RAM Page 1 (41h on 83+ Basic, 81h on everything else) swapped in.
 == Example ==

@@ Line 1: / Line 1: @@
-[[Category:83Plus:Ports:By_Address|07 - Memory Page B]]
+[[Category:83Plus:Ports:By_Address|07 - Memory Page B]] [[Category:83Plus:Ports:By_Name|Memory Page B]]
 [[Category:83Plus:Ports:By_Name|Memory Page B]]
 == Synopsis ==
 '''Port Number:''' 07h

← Older revision		Revision as of 17:48, 28 March 2005
Line 1:		Line 1:
		+	[[Category:83Plus:Ports:By_Address\|07 - Memory Page B]]
		+	[[Category:83Plus:Ports:By_Name\|Memory Page B]]
	== Synopsis ==		== Synopsis ==
	'''Port Number:''' 07h		'''Port Number:''' 07h

@@ Line 5: / Line 5: @@
 '''Function:''' Flash/RAM Memory Paging (Bank B)
-This port controls what page is swapped into Memory Bank B (see comments).
+This port controls what page is swapped into Memory Bank B (see comments). On the TI-84+CSE, port [[83Plus:Ports:0F|0F]] also affects MemB.
 === Read Values ===

@@ Line 23: / Line 23: @@
 == Example ==
-  <nowiki>push af
+  <nowiki> di
-in a,(7)
+ push af
-push af
+ in a,(7)
-ld a,1
+ push af
-out (7),a
+ ld a,1
-; do stuff that needs page 1 swapped in
+ out (7),a
-pop af
+ ; do stuff that needs page 1 swapped in
-out (7),a
+ pop af
-pop af</nowiki>
+ out (7),a

@@ Line 7: / Line 7: @@
 === Read Values ===
-* The current port mapped to Memory Bank B (see comments).
+* The current port mapped to Memory Bank B.
 ** 83+ Basic: If a RAM page is swapped in, the port reads the RAM page number with bit 6 set. If a ROM page is swapped in, the port reads the ROM page number with bit 6 reset.
 ** 83+ Silver, any 84+: If a RAM page is swapped in, the port reads the RAM page number with bit 7 set. If a ROM page is swapped in, the port reads the ROM page number with bit 7 reset.
 === Write Values ===
-* The page number to swap into Memory Bank B (see comments).
+* The page number to swap into Memory Bank B.
 ** 83+ Basic: If bit 6 is set, bit 0 will choose between the two RAM pages (40h or 41h). If bit 6 is 0, bits 0~4 select a page from ROM (00h through 1Fh).
 ** 83+ SE, 84+ (any): If bit 7 is set, bits 0~2 will choose any of the 8 RAM pages (80h through 87h). If bit 7 is 0, bits 0~5 on the 84+ Basic, or bits 0~6 on either SE will select a page from ROM (00h through 3Fh or 7Fh).
 == Comments ==
-The behavior of this port changes in different memory map modes. See [[83Plus:Ports:04|Port 04h]] for details about memory map modes.
+Under normal circumstanes this port controls the page mapped to 8000h.  The behavior of this port changes in different memory map modes. See [[83Plus:Ports:04|Port 04h]] for details about memory map modes.
 Unless you're really clever, the calculator will crash if you return to TIOS with anything other than RAM Page 1 (41h on 83+ Basic, 81h on everything else) swapped in.