80-Bus News

Doctor Dark’s Diary – Episode 15

Matters Arising

Mike York’s letter in the last issue commented on my remarks about a couple of aspects of Pascal, so I thought it would be a good idea to see if I could justify what I said. First, string handling. The definition of Pascal does not contain any reference to the string handling functions Mike York mentions. I assume that these are a non-standard extension provided in UCSD Pascal . They will make programming of string handling very easy for him, but will also render his programs less portable. As I understood it, one of the aims of Pascal was that if a program worked on one machine, it would work on another. For this very reason, I try to use only standard Pascal when I give you my free routines. It should then be possible to compile the code using any decent compiler, which is surely better than if I told a Com-Pas user that they had to get another compiler to use my stuff? Second, big numbers. I have sometimes had cause to write programs that handle numbers with more than the 36 digits UCSD copes with. In these circumstances, it would seem that I was not “doing it the hard way”, so much as doing it the only way. The whole point of my comments on the subject was to show how Pascal enables you to write programs that work on numbers of a very large size, let us say for the sake of example a hundred digits. I am sorry if I did not make this clear. To avoid any further misunderstanding, I should like to point out that the foregoing remarks are not an attack on either Mike York or the UCSD operating system. I have read a lot about UCSD in the glossy magazines, who rave about it. So when I saw it advertised in the said glossies, I thought, “at last, our prayers are answered.” Then I saw the price........

If Mr R A C Treen of Burgess Hill (see 80-BUS News Vol.2 Issue 1 page 14) had written to me telling me how to get past the Plover room without falling down a pit, I would have told him how to open the clam. But! I now know how to deal with the Plover room, and am able to score 250 out of 350 on the Syrtis Adventure. The next hundred points seem to be much more difficult to get, however. Mr Treen, you need something like a crowbar to open the clam (which actually isn’t a clam at all!), and one of the items of treasure which you may not have found yet is a bit like a crowbar.......

I have found out, with the help of my brother, quite a few useful actions that help with Level 9’s Dungeon Adventure… For instance, I know how to deal with the giant rat, and what the octopus is for. Even the armed skeletons are no longer a threat, but if anyone can explain why the transport system is affected by which collar you are wearing and what the rule governing which collar to wear is, I should be glad.

Book Review 1 – Mastering CP/M

This one is by Alan R Miller, who is a professor at the New Mexico Institute of Technology, and has been using CP/M since it first emerged. It is published by Sybex, and costs £14.50, if you get it from Maplin, which I did. And a most unusual thing happened. Maplin were out of stock, and I had to wait a whole fortnight! Not like them at all, so the book must be selling pretty well. It has about 400 pages, and contains quite a lot of listings of short programs to illustrate the points under discussion.

Any new book on CP/M’s mysteries has to be compared with the ones already out. This is better than Rodney Zaks’ “The CP/M Handbook”, which is really for people who are not doing any programming of their own in machine code. And it is better than Fernandez and Ashley’s “Using CP/M”, which is for similar people, who in addition believe that you learn more if you fill in blank lines all through the book.

There are chapters on such useful subjects as “Adding features to BIOS”. The sort of thing that the other two books needed, and didn’t have. The author