[sebhc] H-89 bus pin out Help
Lee Hart
leeahart at earthlink.net
Tue Mar 14 21:35:03 CST 2006
bill malcolm wrote:
> Thanks for the info: Do you have exact pin out for the 25 pins?
Sure. Here they are. D0-D7 are the data bus, and A0-A15 are the address
bus. The control lines are active high, unless I put a slash before them
(i.e. /WAIT means wait when low).
H89 Memory expansion connectors (left side of board)
---------------------------------------------------
P501, P502, P503 1 = gnd
2 = D0
3 = D1
4 = D2
5 = D3
6 = D4
7 = D5
8 = D6
9 = D7
10 = gnd
P507, P508, P509 1 = +5v
2 = gnd
3 = A0
4 = A1
5 = A2
6 = A3
7 = A4
8 = A5
9 = A6
10 = A7
11 = A8
12 = A9
13 = A10
14 = A11
15 = A12
16 = MEM 0 (gen.pur.port, bit 4)
17 = MEM 1 (gen.pur.port, bit 2)
18 = /RD5 (decoded Read address strobe)
19 = /RD6 (decoded Read address strobe)
20 = /RD7 (decoded Read address strobe)
21 = +12v
22 = -12v
23 = +5v
24 = +12v
25 = gnd
H89 I/O expansion connectors (right side of board)
-------------------------------------------------
P504, P505, P506 1 = gnd
2 = D0
3 = D1
4 = D2
5 = D3
6 = D4
7 = D5
8 = D6
9 = D7
10 = gnd
P510, P511 1 = +5v
2 = gnd
3 = A0
4 = A1
5 = A2
6 = /BRD (buffered Read)
7 = /BWR (buffered Write)
8 = /WAIT
9 = /IO SER.0 (serial I/O select, port#0)
10 = /IO SER.1 (serial I/O select, port#1)
11 = /IO LP (serial I/O select, line printer)
12 = /IO CASS (serial I/O select, cass.tape)
13 = 2.048 MHz clock
14 = 1.8432 MHz clock
15 = /RESET
16 = I/O.0 (gen.pur.port, bit 6)
17 = I/O.1 (gen.pur.port, bit 7)
18 = /INT3 (interrupt priority #3)
19 = /INT4 (interrupt priority #4)
20 = /INT5 (interrupt priority #5)
21 = +12v
22 = -12v
23 = +5v
24 = +12v
25 = gnd
P512 same as P510, P511 except for:
11 = /IO FLPY (hard-sector controller select)
12 = FMWEH (Floppy Memory Write Enable High)
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--
Delivered by the SEBHC Mailing List
More information about the Sebhc
mailing list