Sharp MZ-3500 service manual Bank Select, Ffff, Mao

MZ3500

Operational description

(1)As soon as the sub-CPU is started, it initializes the I/O port and waits for program transfer (IOCS) from the main CPU. This IOCS (Input Output Control System) is the program resident at address 4000H-5FFFH.

(2)As the main CPU loads the information from sector

Communication between Main and SUB CPU

2:3. SD2 (ROM based BASIC)

SD2 is active when "SHARP BASIC" is executed via ROM.

"1" of track "0" of the floppy disk, it loads the IOCS and bootstrap routine to the sub-CPU.

(3)The bootstrap program is loaded next.

(4)The bootstrap program determines rnemory allocation.

BUSRQ H OUTPUT

(ISOLATION OFCOM RAM)

															M S] = I (H)
								M A I N		C P U					MSO = 0 Li	SUB CPU
	M A S 0 0			0 0 0 0					0	0	1	1	1	I	1
BANK	M A 2 °	0	°	0	0 .		0	1	1	1	0	0	0	0	1
SELECT	M A I		0	1		1		0	I	I	0	0	1	I	0
	MAO	0	1		0	1	0	1	0	1	0	1	0	1	0

FFFF	1			I I I
i	R\MA				KAMB
Sffi	4	1	1,	2,	3	4
i\	2
	3

IFF?

ROME ROMC ROMU ROM! ROM 2

IFF?

JROMA

000 0

(MO2		0	0	0	0		1
M	O	1 0	0		1		1	0
M	O	O	0		1	0	1	0

1	1		1	1	1	1
	K \M L				K A M I !
1 1	2	3,	4	1 1	2, 3	4

1.Bank select,MAO~MA3. is effective for memory area COOOH-FFF FH.

2.Bank select, MOO~MA2, is effective for memory area 2000H-3FFFH

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