Z88 Serial Cable
Introduction
None of the Computer Links will work without a Cable.
At the time that the Z88 was designed, there was no standard connector, so Cambridge Computer made up its own. It uses the 9 way 'D' type connector which are used with the modern computers, but they are different in two different ways.
- Mechanically - they do not have the stand-offs to accept the screw down connectors. This means that if a normal computer cable is used, it will not fit completely in the Z88 as the screws on the cable connector will prevent it from plugging into the Z88.
Z88 9 way connector
The Z88 Serial Cable connector do not have any screws fitted, so it fits into the Z88 perfectly. So why not just remove the screws you may ask?
- Electrically - The bad news that even the connections to the nine pins are different.
There is a lot of misinformation on the net about making your own cables. This is because initially Cambridge used IMP/EXP built in software which used software handshaking and just 3 connections. This was later replaced with PC Link II which used hardware handshaking and used more connections for hardware handshaking. Other companies then also started making computer cables for the Z88 which may have used different wire colours and worked with their software, but may still not work with the current one.
Before using any cable, please check it against the pinouts given here, or just get the correct cable. Then any of the transfer programs may be used with the Z88 confidently.
9 way Cable with screws
Z88 Links to be modified
| Z88 | Desktop | 25 Way PC Cable | 25 Way Serial Printer Cable | Z88-To-Mac | |||
|---|---|---|---|---|---|---|---|
 Computer Cable |
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| Z88 to Desktop RS-232 Cable | Z88 Cables for other devices modified to be used with the Desktop using optional USB Serial adapter. Z88 plug used but the other connector removed & replaced with a 9 way 'D' socket for the Desktop. | ||||||
| Z88 | Desktop USB Serial Socket | Desktop Old Standard Serial Socket | Printer Plug | Old Mac modem connector | |||
| Connector diagrams are exterior views |
9 way |  Cable |  9 way |
25 way |
25 way 'D'plug |
Mini-DIN-8 | |
Signals | Pin-outs | Pin-outs | Colour of cable to be connected to the Desktop NOTE: Do not rely on these colours. Different manufactures used different colours. | Signals | |||
| 1 | DO NOT USE for for RS232 signals. It carries 5v at 10uA even when the machine is off. Not Used | ||||||
| TxD | 2 | | 2 | Black | Red / Black | Brown | RxD |
| RxD | 3 | | 3 | Red | Yellow | Red | TxD |
| RTS | 4 | | 8 | Brown | Purple | Orange | CTS |
| DCD | 8 | 4 | Not Used | DTR | |||
| CTS | 5 | | 7 | Yellow | White / Black | Yellow | RTS |
| 6 | 6 | Not Used | |||||
| GND | 7 / Gnd | | 5 / Gnd | Orange & Shield | Blue / White & Shield | Green | GND |
| DTR | 9 | | 1 / 6 | All four pins (8 - 9 on Z88 and 1 -6 on other side) connected for Eazylink handshaking. | DSR | ||
| See Appendix B in the Z88 User Guide for full explanation. | |||||||
Recently, the older type of Z88 computer cables have appeared on the market. These are:
- 25 way to Z88 Cable and
- Z88 to Mac Cable
If you are handy with a soldering iron, or wish to buy an adapter, the following give clear instructions on how to modify these cables and save money from buying the standard cables.
Benny Boogaert shows you how to modify these cables..
Modifying Z88 to Mac Cable to 9 way PC cable. | |||
|---|---|---|---|
1. Cut off 2. Strip |
| 3. Brown 2 |
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4. Yellow 7 |  | 5. finished |  |
6. connector |
| 7. cables |
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8. comms linux | |||
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Modifying Z88 to PC Cable - 25 way to 9 way socket | ||||
|---|---|---|---|---|
| black2- red3- orange5 yellow7- brown8 |
| red2- yellow3- blue5 |
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| white7- purple8 |
| Finally yellow7- brown8 |
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