Monitoring temperatures using the VELA

There were at least two variants of temperature sensor for the VELA,

VELA SAM based temperature sensors

The modular SAM add on had three different temperature sensor modules manufactured for the VELA which operated at different temperature ranges which were:

  • 0deg C to 50deg C (priced @ £49)
  • -50deg C to 150deg C (priced @ £49)
  • -100deg C to 750deg C (priced @ £58)
The image below shows the -50deg C to 150deg C sensor adaptor and probe rated to 150deg C.

The VELA SAM4, temperature sensor adaptor and 150deg C temperature probe

VELA Temperature Module using the digital port

A third party, four channel sensor was also available and was plugged into the VELA using its digital port to provide power and a data connection to the module.

The VELA Temperature module adapter

The module could accept connections from four simple thermister based temperature probes and convert and relay the data back to the VELA.

A VELA Temperature module probe

A close-up of the thermistor reveals that they are simply soldered to the end of a twisted pair of wires and protected by a heat resistant plastic sleeving with a dab of glue on the end to stop any liquid ingress. They're rated to measure temperatures from -24.9 deg C to 110 deg C.

Thermistor temperature probe

VELA Technical Downloads


The following ROM images are Mk I EPROMS and are incompatible with the ISL1* ROM from the VELA Mk II.  You can use the Mk I ROMs in a VELA Mk II or VELA PLUS but there are several differences in the data formats they produce when exporting from the VELA so when sending data to a microcomputer, it should be told it is connected to a Mk I VELA.

The following ROM images are for the VELA Mk II as indicated by a red *.

The following ROM images are for the VELA PLUS as indicated by a green *.

The following ROM image is for the SAM4 Sensor Adaptor Module

  • SAM* ROM

This final ROM is the RS Components ROM image that replaces ISL1* for their re-branded Multi-function Intelligent Data Logger.

IC Datasheets

The following datasheets cover all of the IC chips that are used in the VELA Mk. II data logger.


If you've come across this page because you've found a dusty old VELA or any of the peripherals I've mentioned on the site in the store cupboard of the science department and you're wondering what you can do with it... You could always consider donating it to a good home such as mine where it would be reunited with a BBC Micro, archived for the future and used!

Although I now have many VELA related items, I am still missing many more bits and pieces so if you happen to have a VELA, any VELA software, manuals or related VELA handbooks, then I'd still be very interested in hearing from you so please do get in touch!

Of particular interest are any VELA SAM4 compatible modules and software for the RM380Z, Apple II and IBM-PC's of the day which currently are lost to the mists of time with the prospects of viable floppy discs containing the software being more remote as the years go by.

For a full list of VELA related items I'm looking for, please check out my VELA - WANTED, DEAD or ALIVE! page.


I'd like to thank Jon Neville-Green of The Discovery Academy School in Stoke-On-Trent who kindly arranged for me to obtain their VELA which had been gathering dust in exchange for a donation to the Science department at the Academy. Thank you very much.

I'd also like to thank Cathy Herriman of Sherborne School for providing me with a full surplus set of manuals and supporting books and documents for the VELA in exchange for a donation to the School funds. Thank you.

Finally, I'd like to thank Mr Robert Boyd of Glossop High School in Adelaide and Dr. Ashley Clarke (one of the original creators of VELA) who have both contributed information in various e-mails that has allowed me to build up and present a wider picture of the VELA data logger and what it could do.