In a BESM-6 disk image I can see bits and pieces of something that looks like a strange interactive scripting language:
[start of disk block]
<LET=P11=%X01
<IEQ=P11=%377
<LET=P11=1
<END
<LET=P12=0
<REP=META=P12=%P11
<ADD=P12=1
<<MO2
<<K31
<<MO5
<<K35
... [a dozen more <<MOn and <<Knn lines]
<MES= ROUND %P12 ENDED [originally in Russian]
<LAB=META
[end of file marker, zeros to the end of the block]
Here one can guess that <LET
is an assignment operator, <IEQ
is a conditional, <REP
is a loop up to a label, <MES
means "message", the % sign in a message text is an interpolation operator, etc.
The <<
lines are unclear.
Another example I've found is (with texts translated)
<МЕS=
<МЕS=*** IBM TAPE VERIFIER *** ( 03.02.89 )
<МЕS=
<GЕТ=11=VOLUME-
<GЕТ=13=RECORD DENSITY (8, 32, 63)-
<GЕТ=14=TAPE DESIGNATOR (MAX. 21 CHARS.)-
...
As all the keywords are in English, a Western prototype is likely.
In pieces of the documentation in Russian I was able to find, this functionality is called "interactive macrogenerator" (just like that, without a proper name). Searching for that in English finds a few documents about TRAC, which is a different language.
Searching in Russian finds a page which mentions MES
, LET
, GET
, IEQ
, etc. The page title suggests that the name of the language was likely PAGEN, and the links below, mentioning Soviet DEC clones - that it could have stemmed from DEC.
Searching for 'pagen', or even "!pagen +DEC" leads nowhere.
What was the language called PAGEN which used less-than signs to start keywords and equal signs as separators?
<<
lines could be parameters to some programm - aka inpul lines on a different programm level. I've seen several systems on systems with combined command and parameter input (read one punch card stack holding the job and its data) using such a level indicator to enable skiping data in case the programm execuion get aborted before all data is read.<GET
with a prompt). This is likely a small part of the script, so it's hard to tell what it was doing, but the language itself doesn't look original. I've heard of AC-6 but have never seen it.