[HECnet] Kermit-20 DECnet Implementation

[Thomas DeBellis]

I needed to have a separate transport mechanism for testing both the 
Tops-10 and Tops-20 FAL, NFT and DAP implementations.  I wanted to be 
able to compare files to make sure I hadn't messed anything up.  I also 
thought that a speed comparison might perhaps be of interest, but 
otherwise not directly useful.

I've modified K20MIT to be able to transfer files both over DECnet 
Network Remote Terminals and pseudo-terminals.  I did the 
pseudo-terminal part first so I could debug the alternate line code more 
easily without having any DECnet issues getting in the way.  Once I'm 
satisfied that Kermit will transfer over a non-physical line, I can rule 
out any problems I have debugging the DECnet code.  In other words, I'll 
know that, whatever issue I bump into, it will be reasonable to assume 
that it is related to NRT transport and not anything Kermit is doing.

Right now, a lot of sparks have come flying out because I am taking code 
that is nearly 40 years old that grew up dealing with with a DH11 front 
end line and wrenching it into using virtual terminals.  However, 
earlier this evening, I had my first pseudo-terminal transfer.  The file 
was the ASCII text for Ralph Gorin's "Introduction to Assembler Language 
Programming" book. This is about 1.5 megabytes long and takes up 621 
pages on disk, which I imagined would be a 'reasonable' size.   Kermit 
says it clocked about 815 Kbps doing the transfer, but I really wouldn't 
have any idea what that number means.  A FILCOM shows that the files 
match to the byte, which is the important part.  Details below.
     —T

------------------------------------------------------------------------

Kermit-20>*connect* [KERMIT-20: Loopback connection to VENTI2:: via 
PTY7: using TTY22:, type <CTRL-\>C to return.] Kermit-20>*set delay 15* 
Kermit-20>*server* Kermit Server running on DEC-20 host. Please type 
your escape sequence to return to your local machine. Shut down the 
server by typing the BYE command to KERMIT on your local machine. 
[KERMIT-20: Returning to local system, VENTI2::] Kermit-20>*show line* 
TTY for file transfer: 22 (assigned TTY line, KERMIT-20 is _LOCAL_) 
Handshake: None Flow-Control: XON-XOFF Parity: None Duplex: Full Speed: 
(Unknown) Break Simulation: Disabled TVT Binary: On TVT Negotiate: 
Automatic Log: (none) Kermit-20>*cwd ps:<slogin>* [Connected to 
TOMMYT:<SLOGIN>] Kermit-20>*send doc:tops20_ASSEMBLER_PROGRAMMING.TXT.1 
(as) * Kermit-20>*statistics* Maximum number of characters in packet: 80 
received; 80 sent Number of characters transmitted in 19 seconds Sent: 
1711619 Overhead: 124378 Received: 138712 Overhead: 138712 Total: 
1850331 Overhead: 263090 Total characters transmitted per second: 97385 
Effective data rate: _835390_ bps ILDB: 0 SIN: 0 SIN Max: 0 BIN: 138712 
Interpacket pause in effect: 0 sec Timeouts: 0 NAKs: 0 Kermit-20>*push* 
[KERMIT-20: PUSHing to new EXEC.] [POP from Exec to return.] @*vdir 
/since today* TOMMYT:<SLOGIN> TOPS20_ASSEMBLER_PROGRAMMING.TXT.1;P774200 
621 1587241(7) 13-Nov-2021 17:29:35 SLOGIN Total of 621 pages in 1 file 
@*defINE f1: (AS) doc:tops20_ASSEMBLER_PROGRAMMING.TXT.0 * @*defINE f2: 
(AS) h:tops20_aSSEMBLER_PROGRAMMING.TXT.0* @*filcom* **tty:=f1:,f2:* _No 
differences encountered_ **^Z* @




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