Talon2000
Well-known member
Is there a way to correlate the memory maps given in the game manual to the actual chip locations on the board?
For example here's the manual information on Liberator memory map.
There being 12 memory chips.
Is there a book out there that would teach me more about these old processors and memory allocations? I would like to learn more about how memory is accessed.
HEX R/W D7 D6 D5 D4 D3 D2 D2 D0 function
17 ---------+-----+------------------------+------------------------
18 0000 D D D D D D D D XCOORD
19 0001 D D D D D D D D YCOORD
20 0002 D D D BIT MODE DATA
21 ---------+-----+------------------------+------------------------
22 0003-033F D D D D D D D D Working RAM
23 0340-3D3F D D D D D D D D Screen RAM
24 3D40-3FFF D D D D D D D D Working RAM
25 ---------+-----+------------------------+------------------------
26 4000-403F R D D D D D D D D EARD* read from non-volatile memory
27 ---------+-----+------------------------+------------------------
28 5000 R D coin AUX (CTRLD* set low)
29 5000 R D coin LEFT (CTRLD* set low)
30 5000 R D coin RIGHT (CTRLD* set low)
31 5000 R D SLAM (CTRLD* set low)
32 5000 R D SPARE (CTRLD* set low)
33 5000 R D SPARE (CTRLD* set low)
34 5000 R D COCKTAIL (CTRLD* set low)
35 5000 R D SELF-TEST (CTRLD* set low)
36 5000 R D D D D HDIR (CTRLD* set high)
37 5000 R D D D D VDIR (CTRLD* set high)
38 ---------+-----+------------------------+------------------------
39 5001 R D SHIELD 2
40 5001 R D SHIELD 1
41 5001 R D FIRE 2
42 5001 R D FIRE 1
43 5001 R D SPARE (CTRLD* set low)
44 5001 R D START 2
45 5001 R D START 1
46 5001 R D VBLANK
47 ---------+-----+------------------------+------------------------
48 6000-600F W D D D D base_ram*
49 6200-621F W D D D D D D D D COLORAM*
50 6400 W INTACK*
51 6600 W D D D D EARCON
52 6800 W D D D D D D D D STARTLG (planet frame)
53 6A00 W WDOG*
54 ---------+-----+------------------------+------------------------
55 6C00 W D START LED 1
56 6C01 W D START LED 2
57 6C02 W D TBSWP*
58 6C03 W D SPARE
59 6C04 W D CTRLD*
60 6C05 W D COINCNTRR
61 6C06 W D COINCNTRL
62 6C07 W D PLANET
63 ---------+-----+------------------------+------------------------
64 6E00-6E3F W D D D D D D D D EARWR*
65 7000-701F D D D D D D D D IOS2* (Pokey 2)
66 7800-781F D D D D D D D D IOS1* (Pokey 1)
67 8000-EFFF R D D D D D D D D ROM
68 -----------------------------------------------------------------
For example here's the manual information on Liberator memory map.
There being 12 memory chips.
Is there a book out there that would teach me more about these old processors and memory allocations? I would like to learn more about how memory is accessed.
HEX R/W D7 D6 D5 D4 D3 D2 D2 D0 function
17 ---------+-----+------------------------+------------------------
18 0000 D D D D D D D D XCOORD
19 0001 D D D D D D D D YCOORD
20 0002 D D D BIT MODE DATA
21 ---------+-----+------------------------+------------------------
22 0003-033F D D D D D D D D Working RAM
23 0340-3D3F D D D D D D D D Screen RAM
24 3D40-3FFF D D D D D D D D Working RAM
25 ---------+-----+------------------------+------------------------
26 4000-403F R D D D D D D D D EARD* read from non-volatile memory
27 ---------+-----+------------------------+------------------------
28 5000 R D coin AUX (CTRLD* set low)
29 5000 R D coin LEFT (CTRLD* set low)
30 5000 R D coin RIGHT (CTRLD* set low)
31 5000 R D SLAM (CTRLD* set low)
32 5000 R D SPARE (CTRLD* set low)
33 5000 R D SPARE (CTRLD* set low)
34 5000 R D COCKTAIL (CTRLD* set low)
35 5000 R D SELF-TEST (CTRLD* set low)
36 5000 R D D D D HDIR (CTRLD* set high)
37 5000 R D D D D VDIR (CTRLD* set high)
38 ---------+-----+------------------------+------------------------
39 5001 R D SHIELD 2
40 5001 R D SHIELD 1
41 5001 R D FIRE 2
42 5001 R D FIRE 1
43 5001 R D SPARE (CTRLD* set low)
44 5001 R D START 2
45 5001 R D START 1
46 5001 R D VBLANK
47 ---------+-----+------------------------+------------------------
48 6000-600F W D D D D base_ram*
49 6200-621F W D D D D D D D D COLORAM*
50 6400 W INTACK*
51 6600 W D D D D EARCON
52 6800 W D D D D D D D D STARTLG (planet frame)
53 6A00 W WDOG*
54 ---------+-----+------------------------+------------------------
55 6C00 W D START LED 1
56 6C01 W D START LED 2
57 6C02 W D TBSWP*
58 6C03 W D SPARE
59 6C04 W D CTRLD*
60 6C05 W D COINCNTRR
61 6C06 W D COINCNTRL
62 6C07 W D PLANET
63 ---------+-----+------------------------+------------------------
64 6E00-6E3F W D D D D D D D D EARWR*
65 7000-701F D D D D D D D D IOS2* (Pokey 2)
66 7800-781F D D D D D D D D IOS1* (Pokey 1)
67 8000-EFFF R D D D D D D D D ROM
68 -----------------------------------------------------------------

