Re: Modem for apple2gs

[supertimer@aol.com (Supertimer)]

CUTblakeney@home.com (Jeff Blakeney) wrote:

>supertimer@aol.com (Supertimer) wrote:
>
>> I have found that even with the accelerator turned off,
>>the IIGS has no problem with a 56k connection to a PC.  You can
>>tell it is faster by comparing a IIGS to PC connection at 38.4k
>>and one at 56k.  This is done in ProTERM 3.1 directly booting into
>>ProDOS 8 (or a shift-boot, then launching ProDOS 8 from Finder).
>>
>>It seems that in this one instance, the 8-bit ProTERM 3.1 is ideal.
>>
>>I am not surprised that the IIGS, even an unaccelerated one, can
>>easily do 56k.  After all, SCSI through the IIGS is several orders
>>of magnitude faster.  Even AppleTalk and the IIGS floppy drives
>>are several times faster.  The IIGS has no trouble transferring info
>>at the paltry 56k speed.
>
>The problem isn't with it being able to handle a 57,600 bps transfer
>rate, it is in taking full advantage of that transfer rate.
>
>What I mean is that when I do null-modem transfers between my PC and
>my IIgs using a port speed of 57,600 bps I can get a maximum transfer
>rate of 5760 cps (57,600 / 10 ; dividing by 10 because every character
>consists of 10 bits, 1 start bit, 8 data bits and 1 stop bit).  I
>believe even directly booting into ProDOS 8 and using ProTerm v3.0 the
>fastest rate I've ever seen is around 3500 cps.

That's because ProTERM v3.0 does not support port speeds above
38.4k.  This was rectified in ProTERM v3.1, which supports port
speeds of 56k.  Believe me, it makes a difference.  What you are
seeing is the limitations of v3.0, not the IIGS.  And again, try turning
off your accelerator.  I bet that even under v3.0, you are not going
to get a drop in cps with the accelerator off as opposed to on.