-=> Quoting Jim Palmer to Richard Town <=-
 JP> 230,400 bps serial communications are no problem on any PowerMac,
 RT> How does one lock a serial port at that speed?
 JP> V.34 modems support  230,400.  (Those who have 'tweaked' V.42bis for 8
 JP> to 1 compression)  The Mac  uses the Zilog 8530 SSC for serial, not the
 JP> National Semiconductor 16650AFN,  the best UART chip for PC's.
Thanx for the info.  But I don't know of any transmission speed that will
support 8: 1 compression on the fly.  1X30.TST is the ITU(t) recognised
test file for testing this, (FReq TEST from origin 7pm-7am London time,
I'm in Win3.11 otherwise at max 57k6) and produces here:

----------  Sat 01 Jul 95, FD 2.12.SW
+  0:22:03  Event 0-@
-  0:22:06  Preparing outbound mail
+  0:22:34  Calling Dayze of Futures Past, 1:106/2001, 00-1-713-458-0237
=  0:22:55  CONNECT 21600/ARQ/LAPM/V42BIS
+  0:22:57  Dayze of Futures Past Systems, 1:106/2001
~  0:22:57    AKA: 81:202/3, 85:842/115
~  0:22:57  SysOp: Craig Ford
~  0:22:57  Using: BinkleyTerm 2.59
:  0:22:57  Tranx: 2FF4955E / 2FF4417F
~  0:22:57   Site: TWO-ston, Texas USA (WAY TO GO ROCKETS!)
~  0:22:57  Flags: 33600,CM,XA,V42B,V32B,H16,V32T,VFC,V34,V34+,FAX,OS2
~  0:22:57  Phone: +1 713 458 0237
   0:22:57  sType: EMSI
*  0:22:58  Sent C:\BBS\FD\OUTBOUND\006A07D1.REQ; 10b, 5 CPS
*  0:24:31  Rcvd C:\BBS\FD\INBOUND\1X30.TST; 983040b, 10685 CPS
+  0:24:43  Mail transfer completed
$  0:24:43  To 1:106/2001,  1:48, 88.
and
----------  Sat 31 Aug 96, FD 2.12.SW
+  0:49:58  Event 0-@
-  0:50:04  Preparing outbound mail
=  0:50:06  RING2
=  0:50:20  CONNECT 28800/ARQ/LAPM/V42BIS
þ  0:50:21  EMSI Recv: Sent EMSI_REQ
þ  0:50:21  EMSI Recv: Received "EMSI_DAT0105"
þ  0:50:21  EMSI Recv: Fetching EMSI_DAT packet, 261b
þ  0:50:21  EMSI Recv: EMSI_DAT packet OK
þ  0:50:21  EMSI Recv: Sent EMSI_ACK
+  0:50:21  TERMINATE Mail System, 2:251/31 private point
~  0:50:21    AKA: Private points
~  0:50:21  SysOp: NDA
~  0:50:21  Using: Terminate 4.00/Expired_116_days_NDA
:  0:50:21  Tranx: 32278C4C / 32278BCC
~  0:50:21   Site: Alton, Hants, England
~  0:50:21  Flags: XA
~  0:50:21  Phone: NDA
   0:50:21  sType: EMSI
þ  0:50:21  EMSI Send: Sending EMSI_DAT
þ  0:50:22  EMSI Send: EMSI_DAT response="EMSI_ACKA490"
þ  0:50:22  EMSI Send: EMSI_DAT acknowledged
*  0:50:23  Rcvd C:\BBS\FD\INBOUND\00FE00EB.REQ; 382b, 0 CPS
%  0:50:31  FREQ: TEST

*  1:08:07  Sent C:\BBS\FD\FILES\1X30.TST; 983040b, 10922 CPS
+  1:08:12  Mail transfer completed
$  1:08:12  From 2:251/31.Private point, 17:52, 0.
Are you really saying that this file (let's keep to the same standard)
will achieve a faster apparent effective thruput just because your
serial port/modem can work at 230k4?
If so, then that would be news to Joe F. at Skokie who reports:
        --------------------------------------------------------
  Speed | 1X30.TST | 2X10.TST | 3X06.TST | 4X04.TST | 5X16.TST |
 ---------------------------------------------------------------
  14400 |   10077  |    3974  |    2339  |    1710  |    6107  |
  16800 |   10867  |    4635  |    2724  |    1996  |    7117  |
  19200 |   10959  |    5260  |    3096  |    2283  |    8062  |
  21600 |   10972  |    5983  |    3502  |    2565  |    9125  |
  24000 |   10980  |    6635  |    3899  |    2851  |   10121  |
  26400 |   10987  |    7153  |    4191  |    3135  |   10318  |
  28800 |   10980  |    7737  |    4571  |    3414  |   10443  |
  31200*|   10994  |    8414  |    4964  |    3700  |   10654  |
  33600*|   10954  |    8904  |    5279  |    3983  |   10701  |
 ---------------------------------------------------------------
 Modem Setup: Courier 7/5/95 firmware, AT&F1 init
 Transmitting System: DSZ.EXE version 6/7/95, on a 386DX-33.
 Receiving System: Procomm Plus (DOS) version 2.01, on a 486SX-25.
 Transfer Protocol: Ymodem-G
Or even with a 244byte LAP-M frame size, V34+ and SREJ only some 32cps
off what I achieve with 128byte no SREJ and vanilla V34 using real POTS.
Do you have any log extracts showing this file being transmitted any
serially faster via POTS?
rgdZ
Richard
--- FMail/386 1.02
---------------