Posted Mon Apr 25, 2011 5:31 PM
Posted Mon Apr 25, 2011 8:22 PM
Posted Tue Apr 26, 2011 12:10 AM
Posted Tue Apr 26, 2011 12:23 AM
Edited by retroclouds, Tue Apr 26, 2011 12:47 AM.
Posted Tue Apr 26, 2011 2:19 AM
Posted Tue Apr 26, 2011 4:28 AM
Edited by ti99userclub, Tue Apr 26, 2011 9:00 AM.
Posted Tue Apr 26, 2011 4:42 AM
retroclouds, on Tue Apr 26, 2011 12:23 AM, said:

Posted Tue Apr 26, 2011 12:20 PM
*** $0000-$7FFF is the 32K BIOS ***
it is also possible to replace the BIOS with an external ROM (see $E000 range)
0000
reset vector (level 0)
0000-0001: WP 0002-0003: PC (%)
0004
level 1 and 2 IRQ vectors (%)
idem. These just seem to reset the system.
000C
additional vectors
0040
XOP vectors (%)
The BIOS doesn't seem to use these for XOPs.
Instead, this is a branch table.
0080
BIOS code
(CRU only: $1EE0-FE: 9995 flag register;
$1FDA: MID flag)
4000
GBASIC
(on the American v2.3 firmware, the GPL
interpreter and VDP RAMLUT co-exist
with GBASIC in this range)
*** $8000-$BFFF is the 16K option ROM area ***
8000
BASIC (Tutor only) and/or cartridge ROM
(controlled by $E100)
To be recognized, a cartridge must have a
$55, $66 or $aa header sequence.
*** end ROM ***
C000
unmapped (possible use in 24K cartridges)
E000
I/O range
---------
9918A VDP data/register ports: $E000, E002
"MMU" banking controls: $E100-E1FF
$E100 write: enable cartridge, disable
BIOS at $0000 (???) -- magic
required at $E110 for this
$E108 write: enable BASIC ROM, disable
cartridge at $8000
$E10C write: enable cartridge, disable
BASIC ROM at $8000
$E110 must be $42 to enable $E100
and to replace the BIOS with
an installed cartridge ROM.
BLWP assumed at $0000 (??).
SN76489AN sound data port: $E200
Device handshaking: $E600
Unknown purpose, disk drive maybe?
Printer handshaking: $E800
This is a standard Centronics port.
$E810 write: parallel data bus
$E820 read: parallel port busy
$E840 write: port handshake output
Keyboard lines: $EC00-$EC7E (*CRU*)
(CRU physical address $7600-$763F)
Cassette lines: $ED00-$EEFF
$ED00 (*CRU*): input level
(physical address $7680)
$EE00 write: tape output zero
$EE20 write: tape output one
$EE40 write: tape IRQ on
$EE60 write: tape IRQ off
$EE80, A0, C0, E0: ???
F000
TMS9995 RAM (*)
F0FC
??
FFFA
decrementer (*)
FFFC
NMI vector (*)
FFFF
Posted Tue Apr 26, 2011 1:30 PM
ti99userclub, on Tue Apr 26, 2011 4:28 AM, said:
Posted Tue Apr 26, 2011 7:04 PM
Posted Tue Apr 26, 2011 7:27 PM
InsaneMultitasker, on Tue Apr 26, 2011 7:04 PM, said:
Posted Tue Apr 26, 2011 10:58 PM
marc.hull, on Tue Apr 26, 2011 7:27 PM, said:
InsaneMultitasker, on Tue Apr 26, 2011 7:04 PM, said:
Posted Wed Apr 27, 2011 1:15 AM
mdorman, on Tue Apr 26, 2011 10:58 PM, said:
marc.hull, on Tue Apr 26, 2011 7:27 PM, said:
InsaneMultitasker, on Tue Apr 26, 2011 7:04 PM, said:
Posted Wed Apr 27, 2011 1:42 AM
OX., on Tue Apr 26, 2011 1:30 PM, said:
ti99userclub, on Tue Apr 26, 2011 4:28 AM, said:
Edited by ti99userclub, Wed Apr 27, 2011 1:43 AM.
Posted Thu Apr 28, 2011 10:16 AM
Posted Fri Apr 29, 2011 1:46 PM
ti99userclub, on Wed Apr 27, 2011 1:42 AM, said:
OX., on Tue Apr 26, 2011 1:30 PM, said:
ti99userclub, on Tue Apr 26, 2011 4:28 AM, said:
Posted Fri Apr 29, 2011 4:13 PM
OX., on Fri Apr 29, 2011 1:46 PM, said:
ti99userclub, on Wed Apr 27, 2011 1:42 AM, said:
OX., on Tue Apr 26, 2011 1:30 PM, said:
ti99userclub, on Tue Apr 26, 2011 4:28 AM, said:
Posted Fri Apr 29, 2011 7:51 PM
ti99userclub, on Fri Apr 29, 2011 4:13 PM, said:
OX., on Fri Apr 29, 2011 1:46 PM, said:
ti99userclub, on Wed Apr 27, 2011 1:42 AM, said:
OX., on Tue Apr 26, 2011 1:30 PM, said:
ti99userclub, on Tue Apr 26, 2011 4:28 AM, said:
Posted Sat Apr 30, 2011 5:50 AM
OX., on Fri Apr 29, 2011 7:51 PM, said:
ti99userclub, on Fri Apr 29, 2011 4:13 PM, said:
OX., on Fri Apr 29, 2011 1:46 PM, said:
ti99userclub, on Wed Apr 27, 2011 1:42 AM, said:
OX., on Tue Apr 26, 2011 1:30 PM, said:
ti99userclub, on Tue Apr 26, 2011 4:28 AM, said:
Posted Mon Oct 10, 2011 2:02 PM
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