Alpha One Memory Map

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Memory Map

The following is a memory map that was generated based on the MAME source code (.180). This information is only as accurate as the MAME driver is. If you see any errors, please let me know what that error is.

The Memory Area is related to where the information is from (CPU, Sound Board, etc..), and it may also reflect what it has in common with other hardware.

Alpha One (Vision Electronics, 1988)

Memory Area:alpha1v_map

Address Range

Length

Function

Description

0x0000-0x6FFF

28672

ROM

0x8000-0x83FF

1024

RAM Write, Shared

m52_videoram_w, videoram

0x8400-0x87FF

1024

RAM Write, Shared

m52_colorram_w, colorram

0xC800-0xC9FF

512

Write Only, Shared

spriteram (// bigger or mirrored?)

0xD000

Read Port, Device Write

IN0, irem_audio, irem_audio_device, cmd_w

0x0001	Start 1	Active Low
0x0002	Start 2	Active Low
0x0004	Coin 2	Active Low
0x0008	Coin 1	Active Low
0x00f0	Unused	Active Low

0xD001

Read Port, Write

IN1, alpha1v_flipscreen_w

0x0001	Joystick Right	Active Low
0x0002	Joystick Left	Active Low
0x0004	Joystick Down	Active Low
0x0008	Joystick Up	Active Low
0x0010	Button 2	Active Low
0x0020	Unused	Active Low
0x0040	Unused	Active Low
0x0080	Button 1	Active Low

0xD002

Read Port

IN2

0x0001	Joystick Right	Active Low
0x0002	Joystick Left	Active Low
0x0004	Joystick Down	Active Low
0x0008	Joystick Up	Active Low
0x0010	Button 2	Active Low
0x0020	Unused	Active Low
0x0040	Unused	Active Low
0x0080	Button 1	Active Low

0xD003

Read Port

DSW1

0x0003	2	Active High
0x0002	3	Active High
0x0001	4	Active High
0x0000	5	Active High
0x0004	Upright	Active High
0x0000	Cocktail	Active High
0x0010	No	Active High
0x0000	Yes	Active High

0xD004

Read Port

DSW2

0x000b	4C_1C	Active High
0x000c	3C_1C	Active High
0x0008	2C_1C	Active High
0x0009	2C_1C	Active High
0x000a	2C_1C	Active High
0x000d	2C_1C	Active High
0x000e	1C_1C	Active High
0x000f	1C_1C	Active High
0x0007	1C_1C	Active High
0x0006	1C_1C	Active High
0x0005	1C_1C	Active High
0x0004	1C_1C	Active High
0x0003	1C_1C	Active High
0x0002	1C_1C	Active High
0x0001	1C_1C	Active High
0x0000	1C_1C	Active High
0x00f0	1 Coin/0 Credit	Active High
0x0070	1C_1C	Active High
0x0060	1C_1C	Active High
0x0050	1C_1C	Active High
0x0040	1C_1C	Active High
0x0030	1C_1C	Active High
0x0020	1C_1C	Active High
0x0010	1C_1C	Active High
0x0000	1C_1C	Active High
0x00e0	1C_1C	Active High
0x00d0	1C_2C	Active High
0x00c0	1C_3C	Active High
0x00b0	1C_4C	Active High
0x00a0	1C_5C	Active High
0x0090	1C_6C	Active High
0x0080	1C_7C	Active High

0xE000-0xEFFF

4096

RAM

(// bigger or mirrored?)

Memory Area:main_map

Address Range

Length

Function

Description

0x0000-0x3FFF

16384

ROM

0x8000-0x83FF

1024

RAM Write, Shared

m52_videoram_w, videoram

0x8400-0x87FF

1024

RAM Write, Shared

m52_colorram_w, colorram

0x8800

Mirror, Read

0x07ff, m52_protection_r

0xC800-0xCBFF

1024

Mirror, Write Only, Shared

0x0400, , spriteram

0xD000

Mirror, Device Write

0x07fc, irem_audio, irem_audio_device, cmd_w

0xD000

Mirror, Read Port

0x07f8, IN0

0x0001	Start 1	Active Low
0x0002	Start 2	Active Low
0x0004	Coin 2	Active Low
0x0008	Coin 1	Active Low
0x00f0	Unused	Active Low

0xD001

Mirror, Read Port

0x07f8, IN1

0x0001	Joystick Right	Active Low
0x0002	Joystick Left	Active Low
0x0004	Joystick Down	Active Low
0x0008	Joystick Up	Active Low
0x0010	Button 2	Active Low
0x0020	Unused	Active Low
0x0040	Unused	Active Low
0x0080	Button 1	Active Low

0xD001

Mirror, Write

0x07fc, m52_flipscreen_w (/* + coin counters */)

0xD002

Mirror, Read Port

0x07f8, IN2

0x0001	Joystick Right	Active Low
0x0002	Joystick Left	Active Low
0x0004	Joystick Down	Active Low
0x0008	Joystick Up	Active Low
0x0010	Button 2	Active Low
0x0020	Unused	Active Low
0x0040	Unused	Active Low
0x0080	Button 1	Active Low

0xD003

Mirror, Read Port

0x07f8, DSW1

0x0003	2	Active High
0x0002	3	Active High
0x0001	4	Active High
0x0000	5	Active High
0x0004	Upright	Active High
0x0000	Cocktail	Active High
0x0010	No	Active High
0x0000	Yes	Active High

0xD004

Mirror, Read Port

0x07f8, DSW2

0x000b	4C_1C	Active High
0x000c	3C_1C	Active High
0x0008	2C_1C	Active High
0x0009	2C_1C	Active High
0x000a	2C_1C	Active High
0x000d	2C_1C	Active High
0x000e	1C_1C	Active High
0x000f	1C_1C	Active High
0x0007	1C_1C	Active High
0x0006	1C_1C	Active High
0x0005	1C_1C	Active High
0x0004	1C_1C	Active High
0x0003	1C_1C	Active High
0x0002	1C_1C	Active High
0x0001	1C_1C	Active High
0x0000	1C_1C	Active High
0x00f0	1 Coin/0 Credit	Active High
0x0070	1C_1C	Active High
0x0060	1C_1C	Active High
0x0050	1C_1C	Active High
0x0040	1C_1C	Active High
0x0030	1C_1C	Active High
0x0020	1C_1C	Active High
0x0010	1C_1C	Active High
0x0000	1C_1C	Active High
0x00e0	1C_1C	Active High
0x00d0	1C_2C	Active High
0x00c0	1C_3C	Active High
0x00b0	1C_4C	Active High
0x00a0	1C_5C	Active High
0x0090	1C_6C	Active High
0x0080	1C_7C	Active High

0xE000-0xE7FF

2048

RAM

Memory Area:main_portmap

Address Range	Length	Function	Description
0x0000	1	Mirror, Write	0x1f, m52_scroll_w
0x0040	1	Mirror, Write	0x1f, m52_bg1xpos_w
0x0060	1	Mirror, Write	0x1f, m52_bg1ypos_w
0x0080	1	Mirror, Write	0x1f, m52_bg2xpos_w
0x00A0	1	Mirror, Write	0x1f, m52_bg2ypos_w
0x00C0	1	Mirror, Write	0x1f, m52_bgcontrol_w

ROM Map for this game

This is the ROM map for the game. This should tell you what address the ROM is at, how big it is, what it's used for.

Memory Area:gfx1

Address Range	Length	Label/Location	Description
0x0000-0x0FFF	4096	14-e3	CRC(cf00c737),chars (Fluke: A5A7)
0x1000-0x1FFF	4096	13-f3	CRC(4b799229) (Fluke: 4534)

Memory Area:gfx2

Address Range	Length	Label/Location	Description
0x0000-0x0FFF	4096	15-n3	CRC(dc26df76) (Fluke: 04E0)
0x1000-0x1FFF	4096	16-l3	CRC(39b9863b) (Fluke: 962C)
0x2000-0x2FFF	4096	17-k3	CRC(cfd90773) (Fluke: 10C2)

Memory Area:gfx3

Address Range	Length	Label/Location	Description
0x0000-0x0FFF	4096	11-k3	CRC(7659440a) (Fluke: CC87)
0x0000-0x0FFF	4096	12-jh3	CRC(7659440a) (Fluke: CC87)

Memory Area:gfx4

Address Range	Length	Label/Location	Description
0x0000-0x0FFF	4096	9-n3	CRC(0fdb7d13) (Fluke: 1CC9)

Memory Area:gfx5

Address Range	Length	Label/Location	Description
0x0000-0x0FFF	4096	10-lm3	CRC(9dde3a75) (Fluke: 6CFC)

Memory Area:irem_audio:iremsound

Address Range	Length	Label/Location	Description
0x7000-0x7FFF	4096	1-a1	CRC(9e07fdd5) (Fluke: 6466)

Memory Area:maincpu

Address Range	Length	Label/Location	Description
0x0000-0x0FFF	4096	2-m3	CRC(3a679d34) (Fluke: 51EB)
0x1000-0x1FFF	4096	3-l3	CRC(2f09df64) (Fluke: A92B)
0x2000-0x2FFF	4096	4-k3	CRC(64fb9c8a) (Fluke: CF02)
0x3000-0x3FFF	4096	5-j3	CRC(d1643d18) (Fluke: 6B09)
0x4000-0x4FFF	4096	6-h3	CRC(cf34ab51) (Fluke: 89D6)
0x5000-0x5FFF	4096	7-f3	CRC(99db9781) (Fluke: CE8E)
0x6000-0x6FFF	4096	7a e3	CRC(3b0b4b0d) (Fluke: 90B1)

Memory Area:proms

Address Range	Length	Label/Location	Description
0x0000-0x01FF	512	63s481-a2	CRC(58678ea8) (Fluke: 5102)
0x0200-0x021F	32	18s030-m1	CRC(6a57eff2),background palette (Fluke: 3ACF)
0x0220-0x023F	32	mb7051-f1	CRC(d8bdd0df),sprite palette (Fluke: 3DD7)
0x0240-0x033F	256	mb7052-h2	CRC(ce9f0ef9),sprite lookup table (Fluke: E72E)