Emma 02

Test-Word can be used on a VIP with printer output and a keyboard as input.

V0-F are stored on memory locations 0FD0.

Opcode	Mnemonic	Parameter	Definition
7xkk	ADD	Vx, kk	Vx = Vx + kk
8xy4	ADD	Vx, Vy	Vx = Vx + Vy, V0 is carry / not borrow
8xy2	AND	Vx, Vy	Vx = Vx AND Vy
2aaa	CALL	aaa	Call subroutine at aaa. The subroutine must end in 00A7 (which is the 'Test-Word' equivalent of RETURN)
Bx..	INP	WORD	Input word (ASCII text until space / 0x20) from keyboard and store at address with high byte from 300+Vx and low byte from 380+Vx
1aaa	JP	aaa	Jump to address aaa
Aaaa	LD	RA, aaa A, aaa	RA = aaa
6xkk	LD	Vk, kk	Vx = kk
8xy0	LD	Vy, Vx	Vy = Vx
Fx00	LD	[RA], Vx [A], Vx	[RA] = Vx, RA = RA + 1
Fxkk	LD	[RA], kk [A], kk	[RA] = kk, RA = RA + 1
8xy1	OR	Vx, Vy	Vx = Vx OR Vy
D.kk	PRINT	kk	Send byte kk to the printer
Dx00	PRINT	WORD	Print word (ASCII text until space / 0x20) from address with high byte from 300+Vx and low byte from 380+Vx
Eaaa	PRINT	WORDS	Print words from pointers stored at address aaa, stopping at code 0xff. Words (ASCII text until space / 0x20) are stored at address with high byte from 300+pointer and low byte from 380+pointer
00A7	RETURN		Return from subroutine
Cxkk	RND	Vx, kk	Vx = random AND kk
8xy6	SHR	Vx, Vy	Vx = Vy SHR, V0 is carry / not borrow
3xkk	SE	Vx, kk	Skip next instruction if Vx = kk
5xy.	SE	Vx, Vy	Skip next instruction if Vx = Vy
4xkk	SNE	Vx, kk	Skip next instruction if Vx != kk
9xy.	SNE	Vx, Vy	Skip next instruction if Vx != Vy
8xy5	SUB	Vx, Vy	Vx = Vx - Vy, V0 is carry / not borrow
8xy7	SUBN	Vx, Vy	Vx = Vy - Vx, V0 is carry / not borrow
0aaa	SYS	aaa	Call CDP1801 code at aaa. The subroutine must end in a RET (D4)
8xy3	XOR	Vx, Vy	Vx = Vx XOR Vy

EMMA 02