Hi, Bob.

BL> FM> I guess they were writing it in an earlier BASIC. I think I saw
BL> FM> something to the effect that you tried it in GWBASIC and that
BL> FM> was indeed the format of their reals.

BL>  Yair... I'm still very confused, but that's a normal learning state
BL>for me.

Join the club!

BL> BL> $007FFFFF, $00800000, and $ff. WTF does this mean? Are they hex
BL> BL> numbers

BL> FM> Yes they are hex numbers, and if you have a non-Turbo Pascal
BL> FM> reference they may not be mentioned.

BL>  Bloody books. Paul pointed me at the C code, and I see they are hex.
BL>I guessed it anyway, but poor VB doesn't have sfr and shl functions.

Doesn't really matter. ALongint shr 24 translates easily to ALongint /
16,777,216. (And before anyone bites me on the bum, we're in BASIC here
so '/' will be integer division.)

BL> BL> Invalue shr 24 worries me too. That's a hell of a shift right.

BL> FM> It's sucking out the exponent, the left-most byte of a 4-byte
BL> FM> number.

BL>  I know bugger-all about binary arithmetic. Me education is lacking.

Draw it, little squares representing 8-bit bytes or 4-bit nibbles. I
find it helps.

BL> FM> then the number is (-1)^S * M * 2^(E-128) and that's what that
BL> FM> code below calculates.

BL>  I saved all that, and will make sense of it later. Thanks, Frank.

Then I made it too hard. That was supposed to elicit a flash "AHA!"

BL> FM> I think you've now been pointed to the bit of C which
BL> FM> implements this.

BL>  Not that it helps much. Bloody C! The code is brilliantly simple,
BL>but like all brilliantly simple C code, it is unreadable. It's fun
BL>being a beginner. You learn lots of stuff, and get horribly confused.

But you've got a good enough background in circuit-based logic to figure
it out. AND, OR, NOT, etc are gates; SHL & SHR are shift registers.

Regards, FIM.

 * * Nothing is ever constant, unless it is dead.
@EOT:

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