8-bit, full capacity
On schematic is chip
select logic. It is practically same as by 8-bit simple IDE interface.
But main advance here is that we work with CF card in memory mode,
where data transfer is 8-bit wide, so no capacity loss. Full
capacity of CF card is available, while interface remains simple. On
table below are other necessary connections between Speccy edge
connector and CF card.| ZX
pin, function |
B6
(D0) |
B7
(D1) |
B8
(D2) |
B11
(D3) |
B12
(D4) |
B10
(D5) |
B9
(D6) |
B3
(D7) |
A11
(A2) |
A22
(A6) |
A21
(A7) |
B18
(/RD) |
B19
(/WR) |
| CF
pin |
21 |
22 |
23 |
2 |
3 |
4 |
5 |
6 |
20
(A0) |
19
(A1) |
18
(A2) |
9 |
36 |
| ZX
pin, function |
A6
GND |
A6 GND | A6 GND | A6 GND | A6 GND | A6 GND | A7 GND | A7 GND | A7 GND | A7 GND | A7 GND | A7 GND | |
| CF
pin |
1 |
8 |
10 |
11 |
12 |
14 |
15 |
16 |
17 |
39 |
41 |
50 |
|
| ZX
pin, function |
A3
VCC |
A3 VCC | A3 VCC | A3 VCC | A3 VCC | A3 VCC | |||||||
| CF pin | 13 |
32 |
34 |
35 |
38 |
44 |
Recommended cards are SanDisk brand, non-high speed ones. IC may be 74HC10, 74HCT10.
Costs: SanDisk CF card of 128MB is around 11 Euro, edge slot connector 1-2 Euro, CF socket is harder to find (and hardest to solder), should cost not more than 2-3 Euro. For data transfer to/from PC you need USB card reader too, what is aprox. 10 Euro (June 2006). 74HC10 is around quarter... EPROM: prices vary - electronic hobbist usually have them, may using Flash EPROM too from some PC MB.
There are big differences in prices of CF cards. Avoid MediaMarkt and Photo shops. Try in computer shops - it is often twice cheaper.
Here you can get CF socket: Crownhill