Prisma 40 Memory-Map

I am still working on the details but the main components are:

00000000 - 0001FFFF    128KByte of boot ROM
00000000 - 000003FF    Cold start interrrupt vectors
00000400 - 000004F5    ROM monitor entry point jump table
000004F6               ROM cold start entry point

00800000 - 0081FFFF    128KByte of SRAM
00800000 - 008003FF    Interrupt vectors in SRAM
00800400 - 008005EF    EEPROM data copied to SRAM

01000000               82596 Ethernet interface
01800000               82596 Channel Attention
02000000 - 02001FFC    2K x 8 dual-port SRAM
07800000 - 07FFFFFF    8MByte of DRAM
10000000               Video buffer control registers
10800000               Bt459 RAMDAC address reg. 0-7
10801000                 "     "       "     "   8-15
10802000                 "     "    control registers
10803000                 "     "    colour palette RAM
11000000 - 111FFFFF    2MByte Video display memory

Prisma 40 I/O processor memory map

This is a partial memory map for the 68302 I/O processor:

00000000 - 00007FFF    32KByte of ROM (AT27C256R)
00010000 - 000107FF    2K x 8 dual-port SRAM
00020000 - 0002000F    68681 DUART
00030000 - 00030FFF    4K internal RAM and control registers
00040000 - 00047FFF    32KByte of static RAM

ROM entry points

The monitor ROM includes a number of entry points for functions that can be called from user programs. The initial console output routine for uClinux uses the character output function to display the startup messages. The entry points look similar to those on the 020 version but they are not identical. I will add to the list here when I have worked out what some more of them do.

00000400               Monitor cold start (power-up/reset)
00000406               Monitor warm start
0000040C               Read character from keyboard into D0
00000412               Output character in D0 to terminal
00000418               Output CR-LF to terminal
0000041E               Output a space chracter to terminal
00000424               Output a text string to terminal
  ...
000004A2               Load data from EEPROM to SRAM
000004A8               Save data from SRAM to EEPROM
  ...
000004AE               Initialize the video buffer ?
000004B4               Output character in D0 to video buffer
000004BA               'C' call to output character to video buffer
000004C0               ???
000004C6               Line draw, ASM call
000004CC               Line draw, 'C' call
000004D2               Clear screen

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