Reviews for 101 programming surprises & tricks for your IBM PC computer

The average rating for 101 programming surprises & tricks for your IBM PC computer based on 2 reviews is 4 stars.

Review # 1 was written on 2015-07-09 00:00:00 Jose Aragon As a programming toolbox especially for the TRS-80 Color Computers 1 and 2, this would have been invaluable. Most of the snippets are very simple, and except for one or two, when taken separately may seem rather unnecessary. But there are enough of them that any Color Computer programmer would likely have learned something very useful. One somewhat minor flaw probably hides a bigger flaw, which is that the listings use both 0 and O for zeroes. On its own this is annoying but it’s usually obvious whether a character is a zero or a letter. But it means that the code was probably typeset by a human rather than output directly from a computer, since the programs simply wouldn’t work if typed in that way. And that means there are probably some errors in the very simple code introduced in the typesetting process. This, for example, which should have provided a very useful lesson in the difference between FIX and INT, instead makes it look like they’re the same thing: 10 R=RND(100) 20 F=FIX(R) 30 I=INT(R) 40 PRINT R 50 PRINT F,"FIX" 60 PRINT I,"INT" The problem with this is that R is always a positive integer, which means that R, F, and I are always the same thing. The author very clearly expects it to have a decimal value—he says it in the accompanying text. He also expects F and I to have different values, which they only will if R is negative as well as floating point. Did the typesetter correct “-RND(0)*100” to “RND(100)”? Or did the author type this section from memory and do so incorrectly? This is the only place that I saw with such a flaw. Its biggest flaw is that, probably because it was written early in the life of the Color Computers, the author hadn’t realized that video memory locations were likely to change. So many of the tricks for quickly manipulating graphics mode instead, on my computer, overwrite the disk operating system. In the very first program, for example, the line “30 INPUT"1536 to 4607";V” had to be changed to “30 INPUT"3584 to 6655";V”. Similarly, the graphic screen rainbow tip had to be changed to: 10 PMODE 1,1 20 PCLS 30 SCREEN 1,0 40 FOR L=3584 TO 6655 STEP 256 50 FOR V=L TO L+255 60 POKE V,V-L 70 NEXT V 80 NEXT L 90 GOTO 90 Many of the tips involve POKEing instead of using the built-in routines; this is necessary on Color BASIC which doesn’t have those routines and sometimes faster on Extended Color BASIC. The by-far-most-useful tip for me involved clearing graphics memory. I had not been aware that the Color Computer automatically reserves space for four pages of graphics. By adding “PCLEAR 1” to the beginning of any program that doesn’t use graphics, it frees up 4,608 bytes of RAM. This is incredibly small by modern standards—it is 0.000013% of the memory on the computer I’m writing this on—but when typing in old programs on an old computer, it makes a difference. I have run across longer adventure programs that wouldn’t fit into the Color Computer without removing some of the code, and this trick will help me not have to do that. There are also useful graphics tips, such as how to handle animation. There’s a very cute porthole with an endless school of 8-bit fish swimming by as one example, and many ways of using random graphics to highlight a title screen or text. Also fun was a simple 3-line “piano” program that played the note immediately on touching the letters A, B, C, D, E, F, or G and which was easily modified to turn the computer keyboard into a piano keyboard with four octaves. There is nothing in here that is a full game or a full home finance program, or anything like that. Each entry is meant to show how to do something so that the trick can be incorporated in your own programs. For that reason, they are kept as short as possible. The three-line piano code, for example, can be three lines because it doesn’t check to see if the letter typed is a valid musical note. And this book is completely useless for learning programming unless your computer is a TRS-80 Color Computer. It is entirely focused on tips and tricks for that computer, as the title says. But with its incredibly short programs and fun tips, it would have been a real inspiration for any Color Computer owner back in the day.

Review # 2 was written on 2015-09-06 00:00:00 Don Hill Walter Iooss, Jr. Photography does NOT get any better.