[Simh] TOPS-20 4.1 Cobol 12c Sample test failure

[Bob Supnik]

It is. Great detective work. Thanks.

/Bob Supnik

On 11/5/2016 5:15 AM, simh-request at trailing-edge.com wrote:
> Message: 1
> Date: Fri, 4 Nov 2016 20:52:33 -0700
> From: Pascal Parent<pascguyz at gmail.com>
> To:simh at trailing-edge.com
> Subject: Re: [Simh] TOPS-20 4.1 Cobol 12c Sample test failure
> Message-ID:
> 	<CAEH2hpQeqBvv5PwfYaM0vJb3rm7KYabe-9Z=G18xPQ0Hv2Eo1g at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> The problem is with this machine intruction:
>
> EXTEND 11(13b8) = CVTBDT convert binary to decimal translated
>
> The processor reference manual states:
>
> *If the instruction is CVTBDT, for the digit substitute a byte from the*
> *right half of location E1+D in the translation table, where D is the*
> *value of the digit, unless this is the last digit in the conversion, in
> which*
> *case make the substitution from the right half of the location if M is 0,*
> *but from the left half if M is 1.*
>
> However, for the last digit the emulator checks the L bit instead of the M.
>
> The fix in pdp10_xtnd.c is:
>
> 308c308
> <                 if ((i == 1) && (AC(p3) & XT_LFLG))
> ---
>> >                 if ((i == 1) && (AC(p3) & XT_MFLG))
> I hope this is correct. The CBL74T test completes successfully with this
> change.
>
> Pascal.