>> But this string:
>>
>> C085 426F6F74206572 DEFM "Boot error"
>> 726F720D0A DEFB #0D,#0A
>> C091 50726573732061 DEFM "Press any key for retry"
>> 6E79206B657920 DEFB #0D,#0A
>> 666F7230726574
>> 72790D0A
>
>Ah, no. You have to include the byte after #0A too!!! I bet it is a 0.
Of course. I wanted to show that the string contained no "$" signs, so it
was possible to just call function #09.
>No, it saves some time... :) It saves a CALL and a RET-instruction.
Mmm... if it wasn't for the unjustified JP (and your smiley!) I could
believe that but... no 8:D 8:D 8:D 8:D
> And
>besides, they use 0 as terminate-character, and not "$"... (I don't
>understand why, for god's sake why does the stringroutine use "$" as
>terminating character??? CP/M-compatibility, okay. But then why did the
>developers of CP/M choose "$" instead of a 0????
Definitely CP/M legacy.
Another source of *BAD HABITS* *:D
>> >Haven't checked that but I'm quite sure, I know quite a bit how Dos is
>> >programmed and I really expect those kind of tricks of them.
>>
>> Tricks? To repeat a ROM function? To use JPs in loopless near jumps??? 8:?
>
>Well okay that's not a trick, I meant it as an expression. But if you want
>to see a Microsoft-trick, try to disassemble (and understand!) the first
>part of the MSXDOS2.SYS-file.
Mmm... you all guys seem very fond of the MSX firmware & system software.
Well, it should be, since this is the first computer I still had not the
need to disassemble / reverse-engineer its ROM!!! 8:)
>But if you really want to know why they used JP: let's just say that JP is
>generally faster than JR, and you will never get 'out of range'-problems, so
>most programmers use JP all the time. I do too. I hardly use
>JR-instructions. Only sometimes, when it's faster than JPs (for example in
>conditional jumps which are 'false' more than 60% of the times they are
>executed).
The best solution is an assembler with optimization capabilities. Again,
like DevPac for ST & Amiga. In restricted memory and speed environments
like all the 8-bit computers any byte and T-state saved has its weight (at
least in your programmer's pride!) 8;)
Kiss you lot.
MARK 2
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