[HECnet] A2RTR downtime

[Thomas DeBellis]

The last version or so of Tops-10 appears to have supported user mode 
extended addressing, which could imply that either the microcode was 
modified to implement Tops-10's semantics or Tops-10 was modified to use 
the Tops-20 microcode.

I think the later happened.  Microcode releases were less frequent than 
monitor releases as I recall, perhaps far less frequent.

The physical memory is the same between the KL and KI ten, so maybe that 
part of Tops-10 didn't need to change too much.  Doing sections would 
have had significant impact, however.

On 10/18/21 9:43 PM, Johnny Billquist wrote:
> I have some vague recollection that T10 in the last incarnation(s) 
> could use the KL10 paging, but I could be remembering wrong.
>
> But maybe there are some other T10 people around who might/could know...
>
>   Johnny
>
> On 2021-10-19 01:13, Peter Lothberg wrote:
>> This is kind of a bit off topic.. But...
>>
>> So I have a lot of T10 7.02 based code for KI10 (using tops10 KI 
>> paging...). None of the PDP10 emulators do T10 KI paging..
>>
>> 7.03 has lots of internal changes that did not work on KI, so back 
>> ported  DECnet 4 etc from 7.03 to 7.02 (remember we had KI CPU's..)
>>
>> Was there 7.02 that used KL10/Tops20 paging? I don't have the dist 
>> tapes any longer?
>>
>> Or is there a PDP10 emulator that do KI Tops10 paging that would run 
>> my 7.02?
>>
>> --P
>>
>> So what's the actual T20 patch for NOV 2021 DECnet?
>>
>> Ps, tops10 does not  "cross compile" between versions well (or at all..)
>> ------------------------------------------------------------------------
>>
>>     *From: *"tommytimesharing" <tommytimesharing at gmail.com>
>>     *To: *"hecnet" <hecnet at Update.UU.SE>
>>     *Sent: *Monday, October 18, 2021 3:00:00 PM
>>     *Subject: *Re: [HECnet] A2RTR downtime
>>
>>     I wouldn't worry about it; I don't use VENTI all that much, 
>> either.     …/Except/ when I do…  Then I have to tell you that it has 
>> proven to
>>     be positively invaluable and I am very grateful for that!
>>
>>     If this were critical, then I'd think about getting off my butt and
>>     putting up Tops-10 somewhere on one of my home systems.  But that
>>     would blow a lot of time; I haven't done a MONGEN since…well, I
>>     honestly can't remember—it's well over four decades and I never knew
>>     that part of it well to begin with.    Come to think of it, I might
>>     have been doing a ONCE and not a MONGEN.
>>
>>     Actually, having a guest account on other HECnet systems has also
>>     proved invaluable for chasing down arcane Tops-20 issues. Thanks 
>> all!!
>>
>>     I reached out to Lars Brinkhoff concerning my Tops-10 patch and he
>>     said he would distribute wherever it made "sense" to do so. If I
>>     get any feedback, I will forward it.  Otherwise, let me know if
>>     there is any way I can provide assistance.
>>
>>     Yes, it is a shame about the STOPCODE, but it would appear that the
>>     maintainer had some different ideas in the mid-1980's when this code
>>     was put in about what the usage of Tops-10 would be.  This comment
>>     is illustrative, the first sentence being key:
>>
>>         _I doubt very much that the date itself has really gone past
>>         2021_.  Probably someone smashed an AC or the routine to get the
>>         time from the monitor is returning junk. However, on November 9,
>>         2021, it appears that many people will see this problem so
>>         prepare your SPR for that date.
>>
>>     I think the problem is that Tops-10 didn't have the kind of die-hard
>>     fanatics supporting it (read, MRC) that Tops-10 did, so stuff like
>>     this was caught and fixed years ago.  D36COM has an edit date of
>>     2001 for this, but since it is from Gorin, it's probably older.
>>
>>     I continue to find Y2K things to clean up, these days mostly in the
>>     listings from various compilers and the remaining CUSP's that MRC
>>     didn't catch.
>>
>>     Another thing I fix are internal time of day comparisons. This is
>>     stored as an unsigned 36 bit fixed fraction having resolution to
>>     about ⅓ of a second, 35 bits bringing you to 27-Sep-2217 20:00:00
>>     EST US, the full 36 taking you to 7-Aug-2576 19:59:59 EST US.  Since
>>     the PDP-10 only has signed comparisons, all single comparison
>>     arithmetic will break in a mere 195 years.  Fixing that double word
>>     signed compares has given me some more breathing room.  In 554
>>     years, I'm sure I'll have thought of something else…
>>
>>         ****
>>
>> ------------------------------------------------------------------------
>>
>>         On 10/18/21 11:19 AM, Robert Armstrong wrote:
>>
>>         ***
>>
>>             *Second* is VENTI; I had wanted to test something on it and
>>             it doesn't appear to be online.
>>
>>         *
>>
>>         Sorry, I’m somewhat lazy about booting it up when the host
>>         system is rebooted.  I don’t use VENTI that much.
>>
>>         **
>>
>>             Had you had any interest in trying it?
>>
>>         It sounds like I’m going to have to.  It’s a shame this STOPCODE
>>         was a halt and not just a debug one; at least the latter would
>>         have allowed the system to continue running.
>>
>>         This also means I have to re-discover how to do a MONGEN and
>>         build.  There was a time, 30 years ago (actually, 40 years ago)
>>         when I could have done it from memory but now I’ll have to read
>>         the manual again
>>
>>
>