| IC number | Manufacturer | Documentation |
|---|---|---|
| Z8400 - Z80 CPU | Zilog | Product specification (PDF), CPU user's manual (PDF) |
| Z8400 - Z80 CPU | STMicroelectronics | Not available |
| IC number | Package | Speed | CBM part number | CBM part description | Replacement parts |
|---|---|---|---|---|---|
| Z8400A - Z80A CPU | 40-pin DIP | 4 MHz | 906150-01 | Z80A CPU | Z0A CPU available from: Conrad Electronic |
| Z8400B - Z80B CPU | 40-pin DIP | 6 MHz | 906150-02 | Z80B Microprocessor 6 MHz |
| Device | Position | Package | Speed |
|---|---|---|---|
| A2090 | U28 | DIP | 4 MHz |
| A2090A | U28 | DIP | 4 MHz |
| C128 revision 6 | U10 | DIP | 6 MHz |
| C128 revision 7 | U10 | DIP | 6 MHz |
| C128D | U10 | DIP | 6 MHz |
| Pin | Type | Name | Signal name | |||
|---|---|---|---|---|---|---|
| A2090, A2090A | C128 revision 6 | C128 revision 7 | C128D | |||
| 1..5 | Output | A11..A15 | KA11..KA15 | A11..A15 | ||
| 6 | Input | CLK | CLK | Z80_PHI via U60 and Q6 | Z80_PHI via U60 and U57 | |
| 7..8 | I/O | D4..D3 | DB4..DB3 via U31 | ZD4..ZD3 | ||
| 9..10 | I/O | D5..D6 | DB5..DB6 via U31 | ZD5..ZD6 | ||
| 11 | Power | +5V | VCC | +5V | ||
| 12 | I/O | D2 | DB2 via U31 | ZD2 | ||
| 13 | I/O | D7 | DB7 via U31 | ZD7 | ||
| 14..15 | I/O | D0..D1 | DB0..DB1 via U31 | ZD0..ZD1 | ||
| 16 | Input | INT_ | _INTRQ | IRQ_ | ||
| 17 | Input | NMI_ | VCC via RN6 | +5V via R34 | +5V | |
| 18 | Output | HALT_ | unused | |||
| 19 | Output | MREQ_ | _MRQ | unused | ||
| 20 | Output | IORQ | _IORQ | Z80I/O | ||
| 21 | Output | RD_ | _RD | connected to pin 1 of U12 | ||
| 22 | Output | WR_ | _WR | connected to pin 1 of U31 | connected to pin 5 of U31 | |
| 23 | Output | BUSACK_ | unused | connected to pin 11 of U37 | BUSACK_ via U37 | |
| 24 | Input | WAIT_ | _CWAIT | +5V | ||
| 25 | Input | BUSREQ_ | VCC via R6 | BUSREQ_ | connected to pins 6 and 8 of U37 and pin 2 of U60 | connected to pins 2 and 4 of U37 and pin 12 of U57 |
| 26 | Input | RESET_ | _XRST | RESET_ | ||
| 27 | Output | M1_ | unused | M1_ | ||
| 28 | Output | RFSH_ | _RFSH via U37 and U29 | unused | ||
| 29 | Power | GND | GND | |||
| 30..40 | Output | A0..A10 | KA0..KA10 | A0..A10 | ||
Copyright © 2003-2010 Ronald van Dijk - All rights reserved
Last update: 8 August 2010