Sinclair ZX80 / ZX81 Forums

I agree with martin, you only have to read the American published Sync magazine to see quite a few advertisements for floppy systems stateside.

Having just read Marks post I checked an 80's advert for a floppy system FDC-100 series single drive...$499!!!

Many many thanks for this Erik.

Just 1 character incorrect causes such error! It is very pleasing that there's always someone who will help those such as myself who are not so smart, I really do love this community and have learned so much from it.

Thanks again, Erik.

Fred.

Very late in the day I know but somehow I missed this. The author of this program also published it in Sync magazine minus the any key to continue thing but although the code looks the same it doesn't work very well. by that I mean every odd iteration the answer is miles out with PI starting as 3.14...

Having visited Bletchley a number of times because of my interest in cryptology in general and being fortunate to have had the friendship of two former Bletchley operatives both now sadly passed, (she Bombe operator, he Hollerith room operator then GCHQ respectively) I think this is a nice and welco...

Many thanks Bukster all seems good now and I did notice checking the system,as you say a lot can be done in 1k and Dr beep has proved that with his fantastic creations which this little gem of yours can sit proudly alongside.

Great work.

If it's any consolation I tried it with the so called hardest grid in the world devised by a Finnish mathematician and it solved quite easily.

This looks more like a monitor problem to me as the "jailbars " as you call them tend to affect the central display square which the zeddy outputs to the monitor and not the margins/top and bottom borders as seen in your picture which seems to show a global effect. I think a comment from Mark would ...

@Bukster. Tried the following grid (see picture) on both emulator and real 81. It never seems to get beyond the third line, going into an endless loop as it were. Have run it on emulator speeded up X100 and still no solution after 2hrs run. Just a heads up nothing more as I still think it's great fo...

Superb work in 1k Bukster. :ugeek: There is a 16k sudoku solver created by Simon Holdsworth that could accompany your version to show what can be achieved in both memory sizes and can be found here on his most excellent site... http://www.zx81stuff.org.uk/zx81/supersudoku81/supersudoku81.html Again ...

I use it to burn what ever new 81 ROM comes to the forum and have no need for PC burners which seem to struggle with the 21/25v end of things, I guess I'm a bit old fashioned when it comes to things like this. :lol: That’s because some of the cheap PC EPROM burners were originally designed to burn ...