19 Nov
2021
19 Nov
'21
10:01 p.m.
On Nov 19, 2021, at 3:52 PM, Mark Pizzolato - Info
Comm <Mark at infocomm.com> wrote:
On Friday, November 19, 2021 at 12:33 PM, Reindert wrote:
But how does that process know how to turn a sequence of bytes written to the DUP transmit
register into a packet? To do so, it must know what the particular packet format is. If
a driver is sending BISYNC data, your packet framing algorithm is entirely different from
what it is for DDCMP.
paul
I updated the remark by Bob with this in my
update and could not find that
back in your copy of the mail transcript:
Before I get a storm this from Pdp11_dup.c should accompany it:
The wire protocol implemented is native DDCMP WITHOUT the DDCMP
SYNC
characters both initially and between DDCMP packets.
I still don't understand your problem. The wire protocol is PACKETS, NOT bytes.
The packets are transported over either UDP (as UDP packets) OR via TCP with
a 2 byte packet header indicating the data length. Any packet length is NOT
presented across the simulator<->pdp11_dup device, just the data. On transmit
any interpacket bytes that are the DDCMP_SYNC character are stripped BEFORE
the packet data is presented to UDP or TCP for outbound delivery.
- Mark