23 Dec
2023
23 Dec
'23
7:37 a.m.
On Fri, Dec 22, 2023 at 10:20 PM Chuck Guzis via cctalk
<cctalk(a)classiccmp.org> wrote:
Sync (Bisync, SDLC/HDLC) was fairly popular back in
the day for linking
with mainframes. (Think, for example, IBM HASP). On PCs and the like,
the Intel 8251 was used a lot, but even the Signetics 2651 has the sync
mode, with the ability to recognize a double-byte sync.
The COMBOARD line of Bisync and SNA protocol engines came out of the
HASPBOX product, which was 100% DEC hardware, so we started with a
COM5025 (same as at least one of DEC's sync seral boards) and we later
moved to the Zilog Z8530 (but only ever used its second port as a
local async debug port)
The protocol for any of the above higher-level
protocols is fairly
complex and there are manuals for that
Yeah, implementing Bisync from scratch on a new platform would be
quite an effort. There are a few poorly-documented "gotchas" to work
through/around.
-ethan