[comp.sys.atari.st.tech] MEGA4 internal bus

jhp@sactoh0.SAC.CA.US (Jim H. Puga) (11/28/90)

Well, I hope this works.
Does anyone have the pin-outs to the internal bus in
the Atari MEGA4?  I would appreciate it if someone could
tell me where I could find them.  Thanks in advance.


-- 
-------------------------------------------------------------
- Usenet : jhp@sactoh0.SAC.CA.US                            -
- UUCP   : It's around here somewhere.                      -
-------------------------------------------------------------

s37837k@saha.hut.fi (Jari Lehto) (12/11/90)

The internal bus (Megabus) is directly (parallel) connected with the CPU.
Only thing you have to do is to measure which pin leads to which pin of
the MC 68000. You have the pin assignment of the 68000?


	*** Jari Lehto, jartsu@otax.hut.fi, s37837k@saha.hut.fi ***

alkman@hexagon.se (Stefan Alkman) (12/12/90)

In article <1990Dec11.062945.1551@santra.uucp> s37837k@saha.hut.fi (Jari Lehto) writes:

>The internal bus (Megabus) is directly (parallel) connected with the CPU.
>Only thing you have to do is to measure which pin leads to which pin of
>the MC 68000. You have the pin assignment of the 68000?

Here you have the pinout:s of the Megabuss:

	1  - D4		2  - D5
	3  - D3		4  - D6
	5  - D2		6  - D7
	7  - D1		8  - D8
	9  - D0		10 - D9
	11 - AS*	12 - D10
	13 - UDS*	14 - D11
	15 - LDS*	16 - D12
	17 - R/W*	18 - D13
	19 - DTACK*	20 - D14
	21 - BGO*	22 - D15
	23 - BGACK*	24 - GND
	25 - BR*	26 - A23
	27 - GND	28 - A22
	29 - CLK8	30 - A21
	31 - GND	32 - GND
	33 - HALT*	34 - A20
	35 - RESET*	36 - A19
	37 - VMA*	38 - A18
	39 - E		40 - A17
	41 - VPA*	42 - A16
	43 - BERR	44 - A15
	45 - ENI 7*	46 - A14
	47 - ENI 5*	48 - A13
	49 - ENT 3*	50 - A12
	51 - FC2	52 - A11
	53 - FC1	54 - A10
	55 - FC0	56 - A9
	57 - A1		58 - A8
	59 - A2		60 - A7
	61 - A3		62 - A6
	63 - A4		64 - A5
-- 
Stefan Alkman					  Voice: +46-19-164787
alkman@hexagon.se     	or         !sunic!kullmar!pkmab!hexagon!alkman
>>>>>>		Tech. College of Orebro,	SWEDEN		<<<<<<