Scor­pio News

A major advantage of this program is the way it successively refines the picture, starting with large blocks of colour, and reducing the size of the block. When you are exploring to find interesting areas, this is much better than waiting ages to see what appears on the screen.

The program is rather primitive in the way it fails completely to allow the user to choose an area while it’s running. Instead, you need to insert co-ordinates in the user input routine, and recompile. As they say in the text books, improvement of this part of the program is left as an exercise for the reader…

Even using the Belectra board, the program takes a long time. And as the size of block being drawn is reduced, the time for a scan of the screen actually quadruples. As a consequence, I have only once let a picture be completed, as yet. Before I carry out a long run like that again, I intend to write a couple of programs to load and save pictures. Using a simple form of data compression, a picture will fit into 32K, with a quarter of this space being redundant. I could take the compression more efficient but this would be a the expense of ease of writing the program

I would have suggested that this program would make a useful benchmark of processor performance, but having seen a Meiko Computing Surface produce a screen of Mandelbrot is about one second, I would have found this computer’s couple of hours too depressing.

Another Super Sale.

I am told that the Scorpio sale was a great success, with the non-working items being particularly popular. This suggests to me that there must still be a lot of people around who do enjoy making their own machines, and making it work. Well, I have some bits equipment for sale too, some of them will need to go to enthusiasts. Or masochists, perhaps? I can be contacted on ____-______ if you want to buy any of this gear, and I might haggle a bit over some of the items.

• Spectrum 48K, issue 2, with VTX5000 modem and some games, including “Doomdark’s Revenge” which is really difficult. This one is £150 including postage and packing. The keyboard is ideal for the rubber fetishists, of course.
• Iotec Iona. An astounding machine in a really high quality case, good keyboard. This has a Z80, 64K of RAM, and a colon display. There are several internal expansion slots, and a printer controller board and disc drive controller board are part of the bargain. List price was around £900, but as the manuals are missing, you could collect it for £250. It is a bit heavy to post…
• An S100 box, with two single sided, single density 8″ dask drives, PSU with colossal transformer, a Z80 processor board, no leas than three memory boards, so it probably has a huge 48K of RAM, and an Input Output board. There is no display or keyboard, but anyone capable of using this would know how to fasten a terminal to it, via its 25 pin socket. Needs collecting as it is very heavy, and is a snip at £200.
• An Ohio Challenger, which was a very popular machine once upon a time. I think this has BASIC built in, and it has been expanded from to 4K to 8K. Wow! Quite a nice machine for the enquiring junior programmer, and the makers of the Superboard copied it almost exactly. Just about postable, for £100.
• Dolphin BD80P printer fitted with Centronics interface. Seven needle head, so hardly NLQ, but probably fine for listings. Again, too heavy to post so it is going to have to be collected, unless you want to pay extra for one of the courier type services! I feel £50 is such a bargain I can’t negotiate here!
• Brand new 8″ drive by Control Data, single sided, single density. £50?
• Dreadful wreck of a Nascom 1, half its chips missing, once the property of a famous technical writer. Comes with badly hammered Nascom 3A PSU remains, and a reasonably undamaged keyboard. This should be useful as spares if anyone bas a Nascom 1 they want to keep going. I’ll post it for ten measly quid.

Quite a list of bargains, I think you will agree. How any of you will be able to resist this amazing series of offers, I cannot image. You may suspect that I am trying to raise money for something, and if you do, you are right. More of this later, if time and the deadline permit…