All addresses are absolute.

GRiD Memory map:
00000 - 0003FF: Interrupt table
00400 - xxxxxx: Video buffer
0297F - For screen 320 x 240 - 9600 bytes long
043FF - For screen 512 x 256 - 16384 bytes long

40000 - RAM end for 256kb option
80000 - RAM end for 512kb option

xxxxx - 9FFFF: APP PROM
80000 - for 128 kBytes according to documentation
90000 - for  64 kBytes according to documentation

C0000 - CFFFF: Optional diagnostic boot ROM. No info how to connect.


DFE00 - DFFFF: memory mapped I/O devices (approx. estimate)

DFE00 - DFE06: Unknown PAL device (4 addresses accordin to 1101 BIOS code)
DFE40 - DFE5F: Not used (or, maybe, something related to BEEP~RUN)
DFE80 - DFE82: Bubble memory controller D7220 (1 address line, 2 addresses)
DFEC0 - DFECF: Modem (approx values)
DFF00 - DFF08: Uart 8274 (2 address lines, 4 addresses)
DFF40 - DFF5F: MM58174А RTC (16 bytes used)/ NVRAM X2210D
               (8 bytes (16nibbles) used according to BIOS and sources)
               (4 address lines, 16 addresses)
DFF80 - DFF8F: GPIB TMS9914A (3 address lines, 8 addresses)
DFFC0 - DFFC2: Keyboard controller (1 address lines, 2 addresses)

Possible address decoder in hardware:
3NAND  8NAND     3to8 DEC  DIRECT  Not used  Address  Device
  110  11111111  000       00000   0        - DFE00   - unknown PAL/Uart/GPIB
  110  11111111  001       00000   0        - DFE40   - not used
  110  11111111  010       00000   0        - DFE80   - bubble
  110  11111111  011       00000   0        - DFEC0   - modem
  110  11111111  100       00000   0        - DFF00   - uart
  110  11111111  101       00000   0        - DFF40   - RTC/NVRAM
  110  11111111  110       00000   0        - DFF80   - GPIB
  110  11111111  111       00000   0        - DFFC0   - Keyboard


E0000 - EFFFF: DMA controller?

FC000 - FFFFF: ROM BIOS 16 Kbytes for all models(1101 - 1139)


GRiD I/O map:
000 - 01F: Intel 80130 controller
000 - 00F: 8259 interrupt controller
010 - 01F: 8253 programmable timer


Interrupts physical (usernameak/mamedev):
IRQ0: serial
IRQ1: bubble
IRQ2: modem
IRQ3: system tick || vert sync
IRQ4: keyboard
IRQ5: gpib
IRQ6: 8087
IRQ7: ring

Interrupts form Source code:
int8087       EQU 0
intGpib       EQU 1
intKeyboard   EQU 2  ; (Never used on CCOS)
intSysTick    EQU 3  ; (intVertSync on compass)
intModem      EQU 4
intBubble     EQU 5  ; (Never used on CCOS)
intSerial     EQU 6
intRing       EQU 7

These interrupts are mapped with lookup table in ROM
Interrupts form Source code and their physical numbers:
            Logical     Physical
intSerial       6           0
intBubble       5           1   ; (Never used on CCOS)
intModem        4           2
intSysTick      3           3   ; (intVertSync on compass)
intKeyboard     2           4   ; (Never used on CCOS)
intGpib         1           5
int8087         0           6
intRing         7           7