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Odyssey2 Macro Assembler
Assembler Manual
What you need to know before you program
Odyssey2 uses the Intel 8048 CPU. Always start with define of:
cpu 8048
org 400h
Odyssey2 has:
4 custom sprites and 12 movable predefined graphic characters on screen.
There are 64 graphic characters including letters and numbers,
ball, 3 types of boats, a plane, man, and others.
Like other computers at the time, graphics characters/sprites are broken down to
8x8 blocks or 64 bits/pixels:
db 10111101b
db 01111110b
db 10110111b
db 10110111b
db 11111111b
db 01111110b
db 11011011b
db 10010001b
Sprites and graphic characters are limited to 8 colors while grid graphics can
have up to 16 colors.
Appendix A: Full Technical specifications:
CPU - Intel 8048 8-bit microcontroller running at 5.37 MHz
Memory:
CPU-internal RAM: 64 bytes
CPU-external RAM: 128 bytes
Audio/video RAM: 128 bytes
BIOS ROM: 1024 bytes
Video:
Intel 8244 with 160×200 resolution
16-color fixed palette
(8 basic colors - black, blue, green, cyan, red, magenta, yellow and white
- with a half-brightness variation (4-bit RGBI));
sprites may only use 8 of these colors
4 8×8 single-color user-defined sprites; each sprite's color may be set independently
12 8×8 single-color characters; must be one of the 64 shapes built into the ROM BIOS;
can be freely positioned like sprites, but cannot overlap each other;
each character's color may be set independently
4 quad characters; groups of four characters displayed in a row
9×8 background grid; dots, lines, or solid blocks
Appendix B: Video graphic control address
Video sprite 0 ctrl 000h
Sprite 0 Control range is 000h - 003h [000h is Xcord, 001h is Ycord, 002h color]
Video sprite 1 ctrl 004h
Sprite 1 Control rande is 004h - 007h [004h is Xcord, 005h is Ycord, 006h color]
Video sprite 2 ctrl 008h
Sprite 2 Control range is 008h - 00Bh [008h is Xcord, 009h is Ycord, 00Ah color]
Video sprite 3 ctrl 00Ch
Sprite 3 Control range is 00Ch - 00Fh [00Ch is Xcord, 00Dh is Ycord, 00Eh color]
vdc character 0 010h
vdc character 1 014h
vdc character 2 018h
vdc character 3 01Ch
vdc character 4 020h
vdc character 5 024h
vdc character 6 028h
vdc character 7 02Ch
vdc character 8 030h
vdc character 9 034h
vdc character a 038h
vdc character b 03Ch
vdc sprite 0 shape 080h
vdc sprite 1 shape 088h
vdc sprite 2 shape 090h
vdc sprite 3 shape 098h
Appendix C: Odyssey2 Character Set
# HEX Character # HEX Character
0 00 0 32 20 A
1 01 1 33 21 Z
2 02 2 34 22 X
3 03 3 35 23 C
4 04 4 36 24 V
5 05 5 37 25 B
6 06 6 38 26 M
7 07 7 39 27 .
8 08 8 40 28 -
9 09 9 41 29 x
10 0A : 42 2A “divide sign”
11 0B $ 43 2B =
12 0C 44 2C Y
13 0D ? 45 2D N
14 0E L 46 2E /
15 0F P 47 2F “block”
16 10 + 48 30 10
17 11 W 49 31 “ball”
18 12 E 50 32 “man right”
19 13 R 51 33 “man right walk”
20 14 T 52 34 “man left walk”
21 15 U 53 35 “man left”
22 16 I 54 36 “arrow right”
23 17 O 55 37 “tree”
24 18 Q 56 38 “slope left”
25 19 S 57 39 “slope right”
26 1A D 58 3A “man forward”
27 1B F 59 3B \
28 1C G 60 3C “sub/ship 1”
29 1D H 61 3D “plane”
30 1E J 62 3E “ship 2”
31 1F K 63 3F “ship 3”
|
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Appendix D: Built in sounds
beep-error 028h
explode 02Eh
alarm 03Ch
select 04Ah
keyclick 056h
buzz 05Ah
select2 05Eh
shoot 06Ah
Appendix E: Joystick reading
call 038Fh
Will read joystick and store to accumulator. Load 000 into Register 1 before
call statement for joystick 0 and 001 for joystick 1
Return Values:
#001h joystick up
#002h joystick right
#004h joystick down
#008h joystick Left
Assembler commands:
Usage |HEX|byte(s)|info
nop
NOP |00|1|No Operation
No operation.
Command is often used as a pause in operation (eat a clock cycle).
anl
ANL A,rr |58|1|AND Logical register A=A&rr
ANL A,@r |50|1|AND Logical memory A=A&[r]
ANL A,#n |53|2|AND Logical Immediate A=A&n
ANL pp,#n|98|2|AND Logical I/O port pp=pp&n
analyze value
The function is great for using to compare keyboard or joystick input.
Note: use with jnz function
example:
anl a,#002h
jnz do_this
Example checks to see if accumalator has the hex value of 02, if so, go to
code that has do_this.
ret
RET |83|2|Return from subroutine
Return to where branched (from subroutine)
call
CALL a |14|2|Call subroutine
jmp
JMP a |04|2|Unconditional Jump
jnz
JNZ l |96|2|Jump if Not Zero If A<>0
Jump if not zero, if true