mhenders@hydra.unm.edu (Stinger) (09/25/90)
Well, I have about a two year old A2000 and decided to install a
1 meg Agnus chip about a month or so ago. The installation went great, I
got a meg of chip ram and everything seemed peachy.... UNTIL...
I tried using my external modem and nothing happened. The modem recieved
no commands from my machine and would send garbled text to the machine.
I tried another cable and another modem to no avail. I've tested the CIA
chips and just about every other chip involved in serial communications.
Everything seemed to be ok there so in a last ditch effort I bought an
internal Supra and it works just fine. What's wrong with my serial port?
AAARRRRGGGGHHHH!
--
(***********************************************************************)
(* /// *)
(* \\\tinger { mhenders@hydra.unm.edu } *)
(* /// ( computer hypocondriac ) *)hgschmie@faui41.informatik.uni-erlangen.de (Henning Schmiedehausen) (09/27/90)
In <1990Sep25.154857.7346@ariel.unm.edu> mhenders@hydra.unm.edu (Stinger) writes: > Well, I have about a two year old A2000 and decided to install a >1 meg Agnus chip about a month or so ago. The installation went great, I >got a meg of chip ram and everything seemed peachy.... UNTIL... >I tried using my external modem and nothing happened. The modem recieved >no commands from my machine and would send garbled text to the machine. >I tried another cable and another modem to no avail. I've tested the CIA >chips and just about every other chip involved in serial communications. >Everything seemed to be ok there so in a last ditch effort I bought an >internal Supra and it works just fine. What's wrong with my serial port? >AAARRRRGGGGHHHH! >-- >(***********************************************************************) >(* /// *) >(* \\\tinger { mhenders@hydra.unm.edu } *) >(* /// ( computer hypocondriac ) *) Check the serial driver chips on your board (MC 1488 / 1489 or SN 75188 / SN 75189). They're probably blown. This often happens to serial ports when you pull out the serial plug while the computer is on. I've changed these chips at about 10 computers, and in 9 of 10 cases (hehe... B-) ) the chips were the problem. But, don't worry, they're cheap (DM 2.- - DM 4.-, about $2-3) Has anyone had similar problems? Mail me about it. Henning (Dr. Music) +-------------------------------------------+--------------------+ | hgschmie@faui09.informatik.uni-erlangen.de| Space is big, | | hgschmie@faui41.informatik.uni-erlangen.de| Space is dark, | | (Henning Schmiedehausen, Glueckstrasse 3 | it's hard to find | | 8520 Erlangen, West Germany, 09131/209611)| a place to park | +-------------------------------------------+--------------------+
Eric.Sanders@f210.n110.z1.FIDONET.ORG (Eric Sanders) (10/08/90)
AREA:UUCP_HRDWR
S> From: mhenders@hydra.unm.edu (Stinger)
S> Date: 25 Sep 90 15:48:57 GMT
S> Organization: University of New Mexico, Albuquerque
S> Message-ID: <1990Sep25.154857.7346@ariel.unm.edu>
S> Newsgroups: comp.sys.amiga.hardware
S>
S>
S> Well, I have about a two year old A2000 and decided to install
S> 1 meg Agnus chip about a month or so ago. The installation went great,
S> got a meg of chip ram and everything seemed peachy.... UNTIL...
S> I tried using my external modem and nothing happened. The modem recieve
S> no commands from my machine and would send garbled text to the machine.
S> I tried another cable and another modem to no avail. I've tested the CI
S> chips and just about every other chip involved in serial communications
S> Everything seemed to be ok there so in a last ditch effort I bought an
S> internal Supra and it works just fine. What's wrong with my serial port
S> AAARRRRGGGGHHHH!
S>
S> --
S> (**********************************************************************
S> (* ///
S> (* \\\tinger { mhenders@hydra.unm.edu }
S> (* /// ( computer hypocondriac )
S> --- D'Bridge B1046/0He
S> * Origin: AFIT Amiga Users BBS/UFGateway (1:110/300)
Look towards the back of the motherboard. There is a chip with 1488 on
it. This is a quad line receiver ( the first to go if something zaps
your serial port). I ended up just socketing this chip. It was real
cheap. I think it cost me like $.75 for a new one. I hope this helps!
--
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