BBC/Elk Problems

By Robert Sprowson
Originally published in EUG #24

I looked through EUG #23 with interest and note that you use a 3.5" disk with your Acorn Electron. Does this use an 8271 disk controller as the BBC does, or does the Electron use the 1770 like in the BBC upgrade kits?

You may see that I am not very well informed regarding Electrons. We used to have one but its screen went funny. It was sent for fixing and a few weeks later a phonecall informed up that it had blown up and would cost more to repair than it was worth. (Or is it that they couldn't be bothered and scrapped it?) I have since encountered a similar problem with a friend's Electron so I took it to pieces myself and cleaned the pins on the Ferranti ULA (The square blob to the west). It fixed it.

I have submitted a program called *SEE for this disk. It allows Mode 7 seamless scrolling up and down. I realise it's probably of limited use on an Electron. Usage: *SEE <fsp>

One of your readers commented on Micromart. This is a company I have not heard of. Is it possible for you to print details?

I am currently working on the following projects for the BBC:

  • HOW TO MAKE A BBC TO PC SERIAL LINK
  • HOW TO MAKE AN EPROM EMULATOR (If you don't have Sideways RAM)
  • HOW TO ASSEMBLE SOURCE CODE OF UP TO 27K ON A BBC IN ONE FELL SWOOP

Robert Sprowson

The Elk has a number of disk drive interfaces. However, as far as I know all the successful machines use the 1770 or the 1771. The Acorn Plus 3, which is Acornsoft's Electron disk interface, used the 1770 with ADFS.

The ULA does seem to cause problems on certain machines. Why I have never found out. Neither of my Electrons has ever suffered but I know of a few that have. Your solution is the right one and, to the best of my knowledge, throwing the machine at the wall never cured this problem.

In the past I have bullied some members who produced software which wouldn't run on an unexpanded Electron but this is a specific Mode 7 item and will appeal to many BBC and Master 128 users as well as Elk owners who have one of the Mode 7 adaptors.

Micromart is actually a magazine which is published every week and carries adverts for second-hand computers and suppliers. Mainly PC but occasionally some 8-bit interest. It's an interesting read if you have some pocket money left over.

Gus Donnachaidh, EUG #24