> Hi, I've found this
>
> http://www.classiccmp.org/pipermail/cctech/2002-July/000553.html
>
> searching for technical specs about the expansion ports of the PPC640.
> In it you write "I have both the (software) technical manual and the service
> manual."
This is a fairly large mailing list, but I suspect it was me who said
that. In any cas, I do have those manuals...
>
> Can you please look at the manuals, for the pinout of expansion ports A anc B?
Sure, here you are.
Expansion A (DB25)
1 +5V _input_
2 T/C
3 A19
4 A17
5 A15
6 A13
7 A11
8 A9
9 A7
10 A5
11 A3
12 A1
13 AEN
14 Ground
15 DACK0/
16 A18
17 A16
18 A14
19 A12
20 A10
21 A8
22 A6
23 A4
24 A2
25 A0
Expansion B (DC37)
1 -20V
2 IRQ2
3 IRQ4
4 IRQ6
5 I/O Rdy
6 DACK2/
7 I/O CHCK/
8 DRQ2
9 CK14 (Osc)
10 MEMR/
11 I/OR/
12 ALE
13 D7
14 D5
15 D3
16 D1
17 -5V input
18 -12V input
19 Ground
20 +12V Input
21 IRQ3
22 IRQ5
23 IRQ7
24 DACK1/
25 DACK3/
26 DRQ1
27 DRQ3
28 MEMW/
29 IOW/
30 RESET (out)
31 CK4 (Clock)
32 D6
33 D4
34 D2
35 D0
36 +12V input
37 +5V input
Note that the power lines are inputs -- the machine is powered from the
expansion unit, not the other way round. Many of the signals come from
irreplaceable custom chips, and should be buffered (Amstrad suggest using
a 74HC244 for this). In particular, the following 16 signals need to be
buffered : A0-A7 IOW/ IOR/ MEMW/ MEMR/ ALE RESET CK14 CK4 The data bus
should be pulled high by external 10k resistors.
>
> My interest is about this statement:
> "2) The PPC has an expansion bus which can be turned into normal
> PC-compatible (8 bit) slots, so you can have an external display adapter"
> The expansion bus is the ISA-8bit bus? Can I use it (rewiring it) for connect
> a ISA card?
You can connect an 8 bit ISA card by matching up the signals, but I would
still advise buffering the 16 signals I mentioned. Note that you need to
provide an external PSU as well.
-tony
Received on Mon Apr 14 2003 - 17:39:01 BST