Connecting the VELA to a microcomputer is relatively straightforward for any computer that possesses an interface with an eight bit user port with one or two control lines or similar. To that end, the VELA can be connected to a variety of 8-bit computers including the BBC Micro, Commodore PET, Commodore 64, a RM 380Z and with a suitable expansion card an Apple computer of the same period. The VELA could even be connected to an IBM-PC compatible computer with the relevant ISA card fitted.
Once connected, using suitable software on the Microcomputer, the data from the VELA could be transferred for the purposes of long term storage on disc or cassette and manipulation by data analysis software such as VELAnalysis for the BBC Micro.
RM 380Z photo ©Electronic System News 1983
The video below shows the VELA connected to my BBC Micro using the example data transfer program found in the Technical Manual which is also available for download from this site as an SSD disc image.
To connect the VELA to a BBC Microcomputer requires some of the pins of the VELA's digital out connection to be mapped to the BBC Micro's User Port. In total, 11 lines must be connected comprising of 8 data lines, 2 control lines and an earth.
The photo to the right shows an original unused mapping PCB that was used in the construction of the cables manufactured by ISL as shown above. The PCB mapped a 26-way ribbon cable from the VELA to a 20-way ribbon cable that connects to the BBC Micro's User Port. Pin 1 of the VELA connects to the top left of the PCB and pin 1 of the BBC's User Port connects to the bottom right. The rest of the mapping is straightforward to follow using the table below.
VELA | BBC Micro | ||
Pin assignment | Pin No. | Pin assignment | Pin No. |
CA1 | 24 | CB2 | 4 |
PB7 | 7 | PB7 | 20 |
PB6 | 8 | PB6 | 18 |
PB5 | 9 | PB5 | 16 |
PB4 | 10 | PB4 | 14 |
PB3 | 11 | PB3 | 12 |
PB2 | 12 | PB2 | 10 |
PB1 | 13 | PB1 | 8 |
PB0 | 14 | PB0 | 6 |
CA2 | 22 | CB1 | 2 |
Earth | 1 | Earth | 19 |
With a suitable ISA card fitted to an IBM-PC compatible, the VELA was also able to transfer data to a PC using software called VelaCom.
ISA I/O card photo courtesy of Robert Boyd (Glossop High School)
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.
The VELA manuals contain software listings for the transfer of data to several computers, the link below contains an SSD disc image containing the source for the BBC Micro transfer code.
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
This final ROM is the RS Components ROM image that replaces ISL1* for their re-branded Multi-function Intelligent Data Logger.
The following datasheets cover all of the IC chips that are used in the VELA Mk. II data logger.