🚀 go-pugleaf

Dear net,

I got a Computer Warehouse Harvard Mac clone in November 97.

It's a re-badge of the Motorola StarMax, which in turn is based on the
Tanzania motherboards used in the Apple 4400 Macs.

It has an 603ev processor, 32 Megs of RAM, 1.2 Gig internal ATA disk,
system 7.6.1, OT 1.1.1, TCP/IP 1.1.1 and FreePPP 2.6.2, and with the
Motorola "internal SCSI installation kit" (which includes a small circuit
board that lengthens a too-short RESET pulse on the SCSI bus that was
occasionally causing problems).

There are known problems with the serial ports on Tanzania architecture
computers. For example, serial devices won't be recognised unless they are
switched on and connected when the Mac boots. The black and white
Connectix QuickCam works badly with the computer. See the StarMax web
site  http://www.starmax.net/ref/issues/index.t  for more details.

However, I used it succesfully with a Global Village Teleport Gold II
modem (14400 bps) to connect to Demon.

Everything was fine until after the summer of 98. I began to get line
drops. Not too many, so it was tolerable.

In December 98 I replaced the modem with a Pace 56 Voice modem (K56Flex
compatible) and added SCSI Umax Astra 1220S scanner, La Cie CD-R and
Toast.

The scanner and CD-R work fine.

The modem connects at 28800 (Tx) 40000 (Rx) with the Demon Energis number
and 31200 (Tx) 33600 (Rx) with Colt. Often they connect at one step below
these numbers.

I tried the ARCHOST number:
atdt0845 079 8022\v1
CONNECT 1200/V34/LAPM/NONE/31200:TX/33600:RX

and then

at&v1
TERMINATION REASON.......... LINK DISCONNECT
LAST TX rate................ 31200 BPS
HIGHEST TX rate............. 31200 BPS
LAST RX rate................ 33600 BPS
HIGHEST RX rate............. 33600 BPS
PROTOCOL.................... LAPM
COMPRESSION................. NONE
Line QUALITY................ 030
Rx LEVEL.................... 020
Highest Rx State............ 67
Highest TX State............ 67
EQM Sum..................... 0019
RBS Pattern................. FF
Rate Drop................... FF
Digital Pad................. None
Local Rtrn Count............ 00
Remote Rtrn Count........... 00
V8bis K56Flex not successful

PROBLEM:

I now get line drops several times an hour. In particular, it seems to
drop when trying to do a lot of processing as well as handling the modem
data transfers, for example while using Fetch or Netscape starting up Java
or a plug-in. I can always get the line to drop by trying to view a
non-trivial VRML file with the WorldView plugin.

In addition, it seems to take a minute for the computer to notice that
the line has dropped - the send and receive lights on the modem are
flashing away until eventually I get a dialogue box asking if I want to
reconnect.

I tried unplugging the modem from the 603e and plugging it into a Duo 230
with system 7.5.0, MacTCP and ConfigPPP. The modem connects at 40000 with
the Demon Energis number. Although I get occasional line drops, I can
download a complete 8 Meg file - the 603e always drops the line in the
first few hundred thousand bytes.

I also tried the Duo and Pace on a different line. The modem connected at
44000 but the line soon dropped on a Fetch download.

ATTEMPTS:

On the 603e I have tried the following without success (in particular,
loading a VRML plug-in dropped the line):

(a) getting BT to "change the gain balance from "up to zero" to "up to
3"";

(b) turn down VM from 48 Megs to 33 Megs;

(c) turn down the port speed in FreePPP from 115200 to 38400;

(d) prune the init string down to AT&F1 \V1

(e) try all the Demon numbers including the Green ROMP;

(f) Clean install of system 7.6.1, OT 1.1.1, TCP/IP 1.1.1, FreePPP 2.5.v3,
Netscape 4.0.4 and CosmoPlayer 2.1 on an external SCSI disk;

(g) including each of the following in the modem init string:
    AT+MS=11,0                     (force V34 mode at 33600 bps maximum)
    AT+MS=11,0,,24000              (force V34 mode at 24000 bps maximum)
    AT+MS=11,0,,14400              (force V34 mode at 14400 bps maximum)
    AT+MS=10,0                     (force V32bis mode at 14400 bps
maximum) (this last one should be equivalent to the Teleport Gold II apart
from the fact I've got error correction and compression)

I tried the Teleport again today and it was fine.

(h) I turned off VM completely and used AT+MS=10,0
It dropped the line yet again.
However, I noted that trying to load my test VRML, Netscape ran out of
memory (the system partition had expanded from 9 Meg to 15 Meg and still
going - there wasn't any left)

HELP!

Do I blame the Mac, the modem, the line or Demon?

-- 
Regards Bob,

Bob Kenyon
email: bob@raspbrry.demon.co.uk