[comp.sys.atari.st] ARK Modem

calvin.bruner@canremote.uucp (CALVIN BRUNER) (09/19/89)

I just "inherited" a 1985 vintage modem.  Actually, in its day it was
obviously one of the best...supports Hayes 2400 and MNP 1.  What I need
to know is if (sigh....never happy!) I can upgrade this beast.  It is
made by a company called ARK Electronic Products.
DDDDDDDDDDDDDDDDCCCCCDI have lifted the cover and
see that it has a Z80 CPU and a chip labelled "65AB V.062485 U4 24K
003096 RDV 2.21".  Also, there is a Z80 SIO/O chip.  I think the chip
with the long label may be the MNP chip?  Anyway, if I replaced the Z80
CPU with a Z80 A, and the Z80 SIO/O with an upgrade (is there one?) can
I get more speed out of this modem?  If the chip I mentioned above has
the MNP algorythms, can it be replaced with a more up to date chip?  Any 
help would be appreciated!!  Ohhh yea...has anyone ever heard of ARK?
---
 * Via ProDoor 3.1aR 

tom@buengc.BU.EDU (Prof. Thomas P. Skinner) (09/20/89)

Never heard of ARK, but your assumption that changing the CPU or SIO
chip to a faster version will increase the data rate is incorrect.  The
data rate on a modem is fixed by the standard used.  In  other words a
1200 BPS modem will only run at 1200 BPS (unless it has other speed
options). The MNP protocols are similar in nature.  It may be possible
to upgrade to a more sophisticated protocol, but again, that has nothing to
do with the speed of the chips.

matthew@sunpix.UUCP ( Sun Visualization Products) (09/28/89)

In article <89091907155409@masnet.uucp> calvin.bruner@canremote.uucp (CALVIN BRUNER) writes:
|I just "inherited" a 1985 vintage modem.  Actually, in its day it was
|obviously one of the best...supports Hayes 2400 and MNP 1.  What I need
|to know is if (sigh....never happy!) I can upgrade this beast.  It is
|made by a company called ARK Electronic Products. I have lifted the cover 
|and see that it has a Z80 CPU and a chip labelled "65AB V.062485 U4 24K
|003096 RDV 2.21".  Also, there is a Z80 SIO/O chip.  I think the chip
|with the long label may be the MNP chip?  Anyway, if I replaced the Z80
|CPU with a Z80 A, and the Z80 SIO/O with an upgrade (is there one?) can
|I get more speed out of this modem?  If the chip I mentioned above has
|the MNP algorythms, can it be replaced with a more up to date chip?  Any 
|help would be appreciated!!  Ohhh yea...has anyone ever heard of ARK?
|---
| * Via ProDoor 3.1aR 


I think your confusing chip quality with throughput. Swapping the CPU or SIO
will provide no inprovement in throughput (It will probably make the unit 1%
more relieable though.

The "65AB V.062485 U4 24K 003096 RDV 2.21" is probably the central core of the
modem electronics.  Your best bet, is to find out who the manufacture of that 
chip is, and get the databook for that part from them.  They may have a compatible
part with higher transfer speed.

Actually your best bet for higher speed, is to get a new modem.  BTW 2400bps is 
nothing to sneeze at. I myself have only a 1200bps modem.


-- 
Matthew Lee Stier                            |
Sun Microsystems ---  RTP, NC  27709-3447    |     "Wisconsin   Escapee"
uucp:  sun!mstier or mcnc!rti!sunpix!matthew |
phone: (919) 469-8300 fax: (919) 460-8355    |