The SamBus aka ‘The SAM Card Cage’ was a multi-port expansion device to allow 4 expansion devices to attach to the Coupé.
The SamBus also featured a battery-backed real-time clock (OKI M6242B) which MasterDOS and B-DOS could utilise for timestamping files.
All devices connected will use up some of the available power, and some will be more power-hungry than others. All future peripherals produced will carry a “Loading Factor” number which will be located near the device’s serial number and prefixed by the letters “LF”. This will allow you to estimate how much power a device is likely to consume. If the “Loading Factor” total is above 200 units for all the devices connected, an external 5v power supply will need to be plugged in to the SAMBUS via the external power connector.
The following peripherals were designed before the SAMBUS was in production, and you should assume the following “Loading Factor” units for them.
|External Drive Interface||15 LF units.|
|SPI||15 LF units.|
|Comms Interface||20 LF units.|
|Voicebox||15 LF units.|
|Sam Drive||50 LF units each|
PDF Manual Scan at www.samcoupe-pro-dos.co.uk
|&00ef||1 second register||S1|
|&10ef||10 second register||S10|
|&20ef||1 minute register||M1|
|&30ef||10 minute register||M10|
|&40ef||1 hour register||H1|
|&50ef||10 hour register||H10|
|&60ef||1 day register||D1|
|&70ef||10 day register||D10|
|&80ef||1 month register||MO1|
|&90ef||10 month register||MO10|
|&a0ef||1 year register||Y1|
|&b0ef||10 year register||Y10|
|&c0ef||week day (0=Sunday)||W|
Apparantly SamCo never sold the additional power unit as it was incorrectly designed:
From Dave Park
I remember they had an external power port, and if you actually needed to plug in an external power supply it would create a ground loop. With a modern SMPS that's fine, but with the old school PSUs of the time it could release the magic smoke, which was why they never released a supply for it.
After SamCo went under a number of similar but less functional units like the Two-up and Three-up appeared, also see the Quazar Euroconnector Expansion Cards.
If you have one of these still then the battery will have leaked by now but if you are lucky you will be able to snip it out, clean with white vinegar to neutrilise the alkali and then again with Isopropal alcohol and fit a new one, see Replacement Parts List.