[comp.sys.mac.comm] ZTerm, Telebit T1000, and flow control

yee@osf.org (Michael K. Yee) (01/04/91)

	Using the combination above, what is the best/fastest setup for flow
	control?  Currently I use the MNP/Enhanced mode on the Telebit @
	9600 baud.  I set flow control to XON and XOFF.

	The question is - Can I use hardware flow control (there are two
	levels on available on the Telebit)?  Or since the MNP/Fast
	connection is suppose to be error free, should I just turn off flow
	control?

	Thanks in advance,

	=Mike
--
= Michael K. Yee		-- yee@osf.org or uunet!osf.org!yee --
= OSF/Motif Development
= "I can't give you brains, but I can give you a diploma." -- The Wizard of OZ

allbery@NCoast.ORG (Brandon S. Allbery KB8JRR) (01/04/91)

As quoted from <YEE.91Jan3110526@pmin7.osf.org> by yee@osf.org (Michael K. Yee):
+---------------
| 	Using the combination above, what is the best/fastest setup for flow
| 	control?  Currently I use the MNP/Enhanced mode on the Telebit @
| 	9600 baud.  I set flow control to XON and XOFF.
| 
| 	The question is - Can I use hardware flow control (there are two
| 	levels on available on the Telebit)?  Or since the MNP/Fast
| 	connection is suppose to be error free, should I just turn off flow
| 	control?
+---------------

I've had no trouble with the T1000 at 9600 baud with no flow control on a Mac
SE.  I don't think you can do hardware flow control, though.  (I may be wrong
about that, but I seem to remember something about it only working with RS422.
Then again, the Mac isn't the only computer I use that uses the same physical
port for both RS232C and RS422, so I may be completely confused.  ;-)

You should NOT use XON/XOFF flow control for file transfers:  Xmodem & Co.,
Kermit, UUCP (there is at least one version for the Mac), etc. expect
transparent communications lines, so software flow control is out.  But note
that if you use no flow control, the T1000 will retransmit packets to the
computer in the case of an overrun until all packets are acked.  (That's a
fringe benefit of the "protocol spoofing".)

++Brandon
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henry@ooc.uva.nl (Henry van Meeuwen) (01/05/91)

llbery@NCoast.ORG writes:
> I've had no trouble with the T1000 at 9600 baud with no flow control on
> a Mac SE.  I don't think you can do hardware flow control, though.  (I
> may be wrong about that, but I seem to remember something about it only

That's not true. Macs do hardwarehandshake just fine. They have no complete
RS232 port, but the most important lines, besides the data in and out, are
there: handshake in and handshake out. With one the computer tells the modem
it can (or can not) accept data, with the other the modem can tell the
computer the same thing. Connect the Macs handshake in with the Telebits
CTS and handshake out with the RTS and you can do the most wierd things:
recieve data with 19k2baud modem to modem and only 300 baud modem to your
Mac (not so good idea...) or use any modem to modem speed with the speed
between your Mac and modem fixed at 19k2baud and of course hardwarehandshake
(s51=5, s58=2, s68=255) (a much better idea, I do it all the time). Your
communication-program must tell the Mac that you want hardware-handshake (most
have an option for that).

Here are my complete register-settings for the Trailblazer:
E1 F1 M1 Q0 T V1 X3     Version BF3.01B
S00=000 S01=000 S02=043 S03=013 S04=010 S05=008 S06=002 S07=040 S08=002 S09=006
S10=007 S11=070 S12=050 
S45=000 S47=004 S48=001 S49=000
S50=000 S51=005 S52=000 S53=000 S54=001 S55=000 S56=017 S57=019 S58=002 S59=000
S60=000 S61=060 S62=003 S63=001 S64=000 S65=000 S66=001 S67=000 S68=255 
S90=001 S91=000 S92=000 S95=000 
S100=000 S101=000 S102=000 S104=000 
S110=001 S111=020 S112=001 
S121=000 

With the following cable:
MacMiniDin   Telebit
  grnd   --- 1 grnd
  grnd 4 --- 7 grnd
  hsko 1 --> 4 RTS
  hski 2 <-- 5 CTS
  TD-  3 --> 2 TD
  RD-  5 <-- 3 RD
  TD+  6 not connected
  RD+  8 --- 7 ground
  ???  7 not connected
  Telebits 6 DSR, 8 DCD and 20 DTR not connected.

Henry van Meeuwen, Amsterdam, the Netherlands
henry@ooc.uva.nl