ECB Bus
Intro
The ECB Bus is a standarized bus for Z80 and 8080 computers; similar to the ISA bus used on 80x86 computers. In theory, ECB cards could be used with different computers - however, in practice, different computer systems have different memory and I/O maps, so one would need to modify the memory and I/O address decoding (on the ECB cards) in order to get them working on other computers.
History
The ECB bus was invented in 1977 by the german company Kontron. ECB originally stands for "Einfach Europaformat Computer Baugruppen" (Simple Europaformat Computer Modules; where "Europaformat" refers to a standarized circuit board size of 160x100mm). ECB is sometimes also referred to as "Europa Bus" or "Europe Card Bus".
The bus is still used in some situations (for example, as by 2010, www.reichelt.de still sells 96-pin "Euro Bus" backplane boards). Confusingly, Kontron themselves are now using the abbreviation "ECB" for PCI-bus based "Embedded Computer Boards", which have little (or nothing) to do with the original ECB bus.
ECB Bus Hardware for CPC
- Schneiderware DIY series (CPC Schneider International magazine)
- Sikos ECB Bus (reviewed in CPC Schneider International 8-1986, page 67)
ECB Bus Pin-Outs
The ECB Bus uses 3x32 pin connectors (96 pins), of which, the middle row is used only for newer "16bit" cards. On normal cards usually 2x32 (64 pins) are connected.
| Pin | A | B | C |
| 1 | +5V | (+5V) | +5V |
| 2 | D5 | (A20) | D0 |
| 3 | D6 | (A21) | D7 |
| 4 | D3 | (A22) | D2 |
| 5 | D4 | (A23) | A0 |
| 6 | A2 | (D8) | A3 |
| 7 | A4 | (D9) | A1 |
| 8 | A5 | (D10) | A8 |
| 9 | A6 | (D11) | A7 |
| 10 | /WAIT | (D12) | (xxx) |
| 11 | /BUSRQ | (D13) | IEI Schneiderware: RAMRD |
| 12 | (A18) | (D14) | (A19) Schneiderware: RAMDIS |
| 13 | +12V | (D15) | (xxx) |
| 14 | -12V Schneiderware: NC |
(IRQ7) | D1 |
| 15 | (-5V) Schneiderware: EXP |
(IRQ6) | (--) Schneiderware: -12V |
| 16 | (2PHI) Schneiderware: HALT |
(IRQ5) | IEO Schneiderware: LPEN |
| 17 | (A17) | (IRQ4) | A11 |
| 18 | A14 | (IRQ3) | A10 |
| 19 | (--) | (IRQ2) | (A16) Schneiderware: ROMEN |
| 20 | /M1 Schneiderware: SOUND |
(IRQ1) | /NMI |
| 21 | (xxx) | (IRQ0) | /INT Schneiderware: ROMDIS |
| 22 | (--) Schneiderware: M1 |
(IOWR) | /WR |
| 23 | (/BAI) | (xxx) | (--) Schneiderware: INT |
| 24 | (UBAT 2V..3V) Schneiderware: 5V ACCU |
(IORD) | /RD |
| 25 | (/BAO) | (MEMRD) | /HALT Schneiderware: CURSOR |
| 26 | (xxx) | (xxx) | (/PCL ;similar to /RESET) Schneiderware: RESET (Reset output from CPC) |
| 27 | /IORQ | (MEMWR) | A12 |
| 28 | /RFSH | (DS0: /DataLSB) | A15 |
| 29 | A13 | (DS1: /DataMSB) | PHI |
| 30 | A9 | (OFF) | /MREQ |
| 31 | /BUSAK | (LOCK) | /RESET Schneiderware: BUSRESET (Reset input to CPC) |
| 32 | GND | (GND) | GND |
Signals in brackets "(...)" aren't available on all ECB variants; the Schneiderware series doesn't support those signals. Moreover, the Schneiderware pin-outs are somewhat customized: Signals HALT, M1, INT, -12V, RESET are mapped to the "wrong" pin numbers, and some non-ECB signals SOUND, CURSOR, LPEN, EXP, ROMEN, ROMDIS, RAMRD, RAMDIS, BUSRESET are added, and, UBAT is listed as 5V in Schneiderware (normally it should be 2V..3V). Aside from the +5V, +12V, -12V supply voltages, the Schneiderware motherboard also has an "AC" soldering point; it's voltage/purpose and it's ECB-pin number are unknown -- it might possibly refer to the ACCU battery (rather than to a analog current AC voltage).
Weblinks
- http://de.wikipedia.org/wiki/Europe_Card_Bus - wikipedia (german) - saying it was invented in 1977
- http://www.hardwarebook.info/ECBbus - hardwarebook (pin-outs) - saying it was invented in 1984 (which is wrong)
- http://www.prof80.de/circ_a02.html - prof80 (other pin-outs) (german)
- http://fixunix.com/cp-m/526627-article-different-versions-german-ecb-bus.html - notes on ECB variants from 1982
