29 Nov
2022
29 Nov
'22
8:26 p.m.
I'm trying to read your message alongside the DAP 5.6.0 spec and getting absolutely
nowhere. None of the terms you mention are in the DAP spec. Can you describe what
you're seeing in terms of the spec? And/or include a (binary format) tcpdump protocol
capture?
paul
On Nov 29, 2022, at 12:41 PM, Thomas DeBellis
<tommytimesharing(a)gmail.com> wrote:
I fixed the bit definition for Not Last Message of Segmented Message from bit 4 to 6 as
per DAP V5.6 and properly defined bit 4 as the Reserved field. In other words, I am
following Tops-10, which I believe to have the correct definitions. Then I finished the
flag breakout logic and tested again some systems. The MIM:: result is of note, viz.:
[Parsing Name message]
[Parsing Attributes message]
[Allocated Receive buffer (Words=531. Len=2086.)]
[Trimmed 381. words from receive buffer]
[Received Date/time Attributes message (Flg=*RESV*,SYSPEC UFlg=1000 Cnt=560.)]
[Parsing Date/time Attributes message]
[Parsing File Protection Attributes message]
[Parsing Name message]
TEST.DIS;1;P775656 2 2560(8) 18-Nov-2013 01:18:27
So what's up with *RESV*? Is (reserved) bit 4 being used for something new (I.E.,
post DAP 5.6) now? If so, what? The UFlg is an octal field for bits that I don't
know about. In this case, MIM:: is sending bit 9 high, which the PDP-10 (which is the
opposite endian) sees as bit 26. What's that?
Just wondering if I'm seeing what I'm seeing here...
On 11/27/22 12:34 AM, Thomas DeBellis wrote:
Whoops, I mistyped the PDP-10 bit definition for bit six; it's 1B29 and not 1B28.
Sigh...
DAP
Bit Bit Meaning PDP-10
Bit Tops-20
DAP Symbol
0 Stream Identification Field Present 1B35 HD$SID
1 Length Field Present 1B34 HD$LEN
2 Extended Length Field Present 1B33 HD$LN2
3 Bit Count Field Present 1B32 HD$BCT
4 Reserved 1B31 HD$SEG
5 System Specific Field Present 1B30
6 Not last message of segmented message 1B29
I looked the Tops-10 DAP flags definitions (in SWIL.MAC); it looks like Tops-10 has it
right and Tops-20 has it wrong, viz:
DAP
Bit Bit Meaning PDP-10
Bit Tops-20
DAP Symbol
0 Stream ID field present 1B35 DF$SID
1 LENGTH field present 1B34 DF$HLN
2 LEN256 field present 1B33 DF$HL2
3 BITCNT field present 1B32 DF$BCT
4 Reserved 1B31 DF$XX1
5 SYSPEC field present 1B30 DF$SHX
6 More data coming 1B29 DF$MOR
Johnny, can you send me the RSX DAP flag definitions when you get a minute?
>
> On 11/26/22 11:58 PM, Thomas DeBellis wrote:
>
> I was writing a routine to break out DAP flag bits to aid debugging when I noticed a
possible discrepancy between DAP V5.6 and Tops-20, viz:
>
> DAP
> Bit Bit Meaning PDP-10
> Bit Tops-20
> DAP Symbol
> 0 Stream Identification Field Present 1B35 HD$SID
> 1 Length Field Present 1B34 HD$LEN
> 2 Extended Length Field Present 1B33 HD$LN2
> 3 Bit Count Field Present 1B32 HD$BCT
> 4 Reserved 1B31 HD$SEG
> 5 System Specific Field Present 1B30
> 6 Not last message of segmented message 1B28
>
> DAP V5.6 reserves bit 4 and defines bit 6 to flag that a segmented message is being
sent and that this is not the last message. In other words, that there will be another
message. Tops-20 is using bit 4 for this purpose and by rights it would appear that it
should be using bit 6.
>
> I will go see if I can't scare up what Tops-10 is doing, but I was wondering if
anyone knew what other OS's are doing.
>
>
>
_______________________________________________
HECnet mailing list -- hecnet(a)lists.dfupdate.se <mailto:hecnet@lists.dfupdate.se>
To unsubscribe send an email to hecnet-leave(a)lists.dfupdate.se
<mailto:hecnet-leave@lists.dfupdate.se>