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From: news@ucf1vm.BITNET
Newsgroups: comp.lang.asm370
Subject: Re: disabling CTRL-BREAK (dos)
Message-ID: <9105300054.AA28231@ucbvax.Berkeley.EDU>
Date: 30 May 91 00:05:20 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: IBM 370 Assembly Programming Discussion List
              <ASM370@OHSTVMA.BITNET>
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Jerry Bryan <BRYAN@wvnvm.wvnet.edu> writes:

>The old Waterloo WATBOL compiler used invalid opcodes on purpose (trapping
>them with SPIE macro) to effect paragraph tracing.  One of the opcodes
>they chose invoked the APL microcode assist on a 370/148 rather than
>generating on operation exception.  We therefore
>found the problem of why tracing wouldn't work by reading the 148's
>microcode.

If the compiler is generating the code, why can't it simply generate a
branch to a trace subroutine.

When I need tracing, I use a set of trace macros I write.  Works great and
does not affect any registers.  The only requirement is that there be a
base register in effect.
--
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