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oric:software:memory_maps

Table of Contents

Memory areas are different depending on whether the system is in HIRES or TEXT modes.

BASIC Text Memory Map

AddressName
0000-00FFPage Zero
0100-01FFStack
0200-02FFPage 2
0300-03FFI/O Area
0400-04FFSedoric Code
0500-B3FFBASIC Program RAM
A000-BFDFHIRES Screen
B400-B4FFSpare Memory
B500-B7FFStandard Character Set
B800-B8FFSpare Memory
B900-BB7FAlternate Character Set
BB80-BF3FTEXT Screen
BF40-BF67Spare Memory
BF68-BFDFTEXT Bottom Screen
BFE0-BFFFSpare Memory
C000-FFFFROM / Overlay RAM

Page 0 (Page Zero)

Locations not used by BASIC

Address RangeNotes
00-0B
BB-BC
F3-F9

Page 3 (I/O)

Memory RangeDevice
0300-030FInternal VIA 6522
0310-0310DK'tronics Joystick Interface (left port)
0310-0313Microdisc FDC WD1793
0310-031FPravetz FDC
0314-031BMicrodisc additionnal I/O registers
031C-031FInternal ACIA 6551 (Telestrat)
0320-032FRS232 extension (Atmos)
0320-0320DK'tronics Joystick Interface (right port)
0320-032FSecond VIA 6522 (Telestrat)
0320-03FFPravetz ROM
0330-035FSpare Memory
0360-0371RTC ICM7170 (Telestrat and Atmos)
0380-03DFSpare Memory
03E0-03E1Oric Lightpen
03E2-03F3Spare Memory
03F4-03FFJasmin FDC WD1773

Other references: Passion ORIC

CPU vectors

Memory locationVector
FFFA-FFFBNMI 6502 Vector
FFFC-FFFDReset 6502 Vector
FFFE-FFFFIRQ 6502 Vector
oric/software/memory_maps.txt · Last modified: 2022/12/29 00:38 by mmu_man

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