Re: Looking for a Hdw-Handshake modem cable ??

[Rubywand <rubywand@swbell.net>]

Michael Elliott writes ...
> 
> Hi-
> I have a Global Village Teleport Gold 14.4 modem hooked up to my IIgs's
> modem port. I am using Spectrum 2.0 to communicate. (have also tried this
> with ProTerm). After trying all port settings I can thing of (Hardware
> handshaking on/off, DCD on/off, XON/XOFF, etc etc) My modem still looses
> characters and garbles the VT-100 screen here and there. I have a brand
> new phone line and very little noise. I have been told I need a modem
> cable capable of "hardware-handshaking". This modem has a db-9 type
> connector instead of the standard db-25. I bought what was labeled as a
> Mac "hi-speed" modem cable, and used a db-25 to db-9 adapter.
> 
> Does anyone know where I can get a good hardware-handshaking capable cable
> for this modem? Most computer places, including the local Apple dealer,
> electronics stores, Radio Shack, and the idiots at Global Village, have no
> idea what I am talking about and give me the "a modem cable is a modem
> cable" line.
> Is there perhaps a source out there on the net for hard to find or custom
> cables?
> 
> Could anyone else who uses Spectrum at high speeds tell me how you have it
> set up (port settings, etc)?
> ....

     If your v2.0 Spectrum manuals are similar to my v1.x manuals, the 
Getting Started and Reference manual has an appendix on Modem Cable Wiring. 
The "A" + "B" connections seem to work well for hardware-handshake/ 
high-speed modemming. (My home brew cable also includes the "C" connection.) 

     You can use an Ohm meter to check GS Din-8-pin <--> DB-25-pin cable 
lines to see that you're getting the needed connections. To check 
connections through the adapter, you can look for continuity of DB-25 
signals to same-name signals on the 9-pin side. Probably, your modem manual 
will show a pin-out for the 9-pin connector.

     If it turns out that you need a new High-Speed modem cable, check with 
Tony Diaz at Alltech.

     As for Spectrum settings, mine work fine for NULL-modem transfers 
(which is, pretty much, my chief use for Spectrum) ...


Port Settings

Baud Rate: 19200 baud (because the PC side of the transfer is limited)
Data Fmt: 8-N-1
Buffer: 64k

X Send LF's
X Hardware Handshake
X Xon/Xoff
0 Char Delay
X DCD Valid
X Modem Port


File Transfer

X Resume Transfers
X BinUP Down
Default Target: RAM5


     Also, you will want to set modem init commands for "High Speed". The 
Spectrum manual and your modem manual should help get these right.

     You do not say whether or not your GS is accelerated. If it is not, you 
will, probably, want to scrap any background tasks (as mentioned by Scott), 
use the fastest display option available, and use the fastest Source or 
Target disk (e.g. RAM disk) in order to minimize delays.


     The Port, etc. setup described earlier works fine for direct transfers. 
A modemming guru may have a number of suggestions for improved performance 
when connecting to a modem at 28.8k or higher baud.     


Rubywand