Peripherals and Sensors for use with VELA

Along with the standard lab equipment that could be directly connected to the VELA, there were some dedicated hardware peripherals that could be used to interface the VELA to even more devices which are shown in the VELA Sensors, VELA Hardware and Software Extensions brochures, and also listed in the January 1989 pricelist.

There were two Sensor Adaptor Modules, the SAM1 and SAM4 which both required the SAM EPROM to be fitted to any VELA using them.

Sensor Adaptor Module 1 - SAM1

The Sensor Adaptor Module 1 was a stand alone box that connected via cabling to the VELA unit. Up to four SAM1 units could be connected to a VELA to provide the same functionality as the SAM4.

SAM1 - Sensor Adaptor Module for VELA

The SAM1 was battery powered and could be connected to the VELA or other devices such as a chart recorder directly providing some extra flexibility in data capture uses when compared to the SAM4 which depends on being connected to a VELA.

Sensor Adaptor Module 4 - SAM4

The SAM 4 was connected to the VELA by plugging it in to the Pulse trigger and channel connectors on the left hand panel of the VELA. The unit then allowed specialist sensors to be plugged directly into the module or separate channels to be used on the "pass through" ports again on the left hand panel. It was previously marketed as the GpSM.

The VELA Sensor module

The pass through connectors on the left of the SAM4 allowed all the normal experimental devices to be attached to the VELA so once fitted, there was no need to remove the SAM4 from the VELA.

The VELA SAM4 pass through input connectors allowed the normal experimental devices to be connected to the VELA without the need to remove the SAM4 from the VELA

On the rear of the SAM4 are the power connections and quick blow fuse holder.

VELA SAM4 power connections

Once connected, the SAM4 provided much more connectivity for the VELA with many sensors being manufactured for it. and the VELA below is shown with a Temperature sensor adaptor and 150deg C temperature probe.

The VELA PLUS connected to a SAM4 sensor adaptor

The SAM4 provides a pass through power supply and comes with an uprated PSU. Power is connected to the SAM4 and chained to the VELA unit to power both devices from one single supply.

VELA PLUS and SAM 4 with power connections

Sensors for the SAM1 and SAM4

Sensors for the SAM1 and SAM4 were interchangeable allowing the same sensors to be used in a wide variety of data capture settings and employed an industry standard connector.

VELA Temperature and Magnetic field sensor adaptors

Probes and other devices were then connected to the sensors to provide the final stage of the monitoring interface with the environment. The picture below illustrates a temperature probe and magnetic field probe.

Temperature and Magnetic field probes for the VELA sensors

The connectors on the rear of the adaptors are keyed 11 pin connectors

Pins on the rear of the VELA Temperature and Magnetic field sensor adaptors

Types of sensor that could be connected to the SAM units include:

Magnetic field sensor

The magnetic field sensor and probe could be used to detect and measure the presense of a magnetic field. By passing the probe over a magnet, the field could be measured as it gets stronger and weaker depending on the position of the probe to the magnet.

The magnetic field sensor and probe was developed to measure fields in the range of +/-25mT.

VELA SAM4 with Magnetic field sensor adaptor and probe

In conjunction with the probe and sensor adaptor, the VELA could be connected to an electromagnetic coil which is used to measure current as a magnetic object passes through, inducing a small current as it goes.

A Helmholtz coil as supplied for the VELA

The coil can be seen in use in the photo below which was part of the StatPack software's sales brochure.

Statpack software shown measuring the effects of the activation of an electromagnetic coil

By passing a magnet such as the ones below through the coil, a small current would be created by induction which is then measured by the VELA.

Two Alinco bar magnets supplied with the Helmholtz coil for experimentation

The magnets are of a standard Alnico construction as indicated on the box that contains them.

Alnico bar magnets manufactured by H Shaw of Sheffield

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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.

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.


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.