80-Bus News

for source text and object code, and thus to a high degree ease development and debugging of programs, and, as Mr O’Farrell points out, the omissions can be overcomed by a bit of programming, if the use of these features is essential.

And now for something completely different. On page 7 in INMC80-5, Mr. B.M. Farrelly of Belfast provides a program for retrieving lost Basic programs. An excellent idea, and very useful indeed, but the little piece of code has a couple of errors in it, I’m afraid, since it doesn’t restore all of Basic’s internal pointers. Only one of them is restored, and, in fact, with a wrong value. The correct code is shown below:

21 FE 10 7E 23 B7 20 FB 22 FA 10 5E 23 56 EB 7E
23 B6 2B 20 F6 23 23 22 D6 10 22 D8 10 22 DA 10
DF 5A

Like the first version, this code can go anywhere in memory as long as it doesn’t overwrite the Basic.

Finally I would like to congratulate everyone on the excellent quality of this magazine. It just grows better and better, and every issue provides me with many hours of interesting reading. Keep up the good work!

Anders Hejlsberg, Poly-Data, Copenhagen.

Free Programs, Sound & Speech

You used to give us occasionally a free program or two to try out on our domestic Nascoms, but lately you have been less generous with these gifts. At one time also you were collecting programs of sufficient merit, and selling copies – or have I got it wrong? Anyway, the rival magazine prints free programs! In the latest issue it has a version of the Towers of Hanoi. Now it so happens that I have written a program of the same nature, but of course much better! I am enclosing a listing of the program in case you are interested. (See elsewhere in this issue – Ed.) It makes good use of Nascom graphics, though I have limited the number of disks to five, since we all have finite lifetimes.

I was very interested in the article on the PHG Electronics Programmable Sound Generator. I bought a similar item from Easicomp Ltd. The generator plugs straight into the Nascom motherboard, and has its own built-in speaker. Like the one reviewed, it uses the AY-3-8910 chip. Control is effected through ports 2 and 3, with the Nascom 2 LSW2-8 I/O Select switch in the ‘Ext.’ position. Documentation is only fair, but it has not proved too difficult to program tunes and sundry noises. I have written a program which converts the Nascom into a keyboard instrument, with a range of three and a half octaves. It is only monophonic, of course, but the tonal quality can be varied by adding various harmonics or altering the sound envelope. I could write up a review of this product if you think it worthwhile. (Please do – Ed.)

Easicomp also advertise a Phonetic Voice Synthesizer at about 150.00. I would be very interested in a review of this – before I splash out that amount of money. The Arfon product sounds alright so long as one sticks to the given limited vocabulary, but to program anything else is, I am told, a fearsome task, and doesn’t sound too marvellous when accomplished. Now the Easicomp synthesizer uses 64 phonemes to build an infinite vocabulary, but what does it sound like? That’s what I want to know.

I look forward eagerly to each issue of the newsletter and hope it won’t be nearly so long before the next issue appears.

John Waddell, Harrow, Middlesex.