30 Nov
2022
30 Nov
'22
1:09 a.m.
What I can tell is what I can see in the sources. And there I have this:
HF.STR=001 ; Stream ID bit in DAP header menu
HF.LEN=002 ; Length bit in DAP header menu
HF.XLN=004 ; Extended length bit in DAP header menu
HF.BIT=010 ; BITCNT bit in DAP header menu
HF.SYS=040 ; System specific field bit in DAP
header menu
HF.SEG=100 ; Segmented msg bit in DAP header menu
HT.BIT is the thing you are seeing which is not there in the DAP 5.6
spec. I don't really know what it is about, but it's something the RSX
DAP have defined anyway.
I can't find any use of it. Looking in the code, I don't even see that
it would ever be set. So I wonder if you made some mistake in your decoding?
Johnny
On 2022-11-29 18:41, Thomas DeBellis 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...
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt(a)softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
------------------------------------------------------------------------
On 11/27/22 12:34 AM, Thomas DeBellis wrote:
Whoops, I mistyped the PDP-10 bit definition for bit six; it's 1B*29*
and not 1B/28/. 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
To unsubscribe send an email to hecnet-leave(a)lists.dfupdate.se