Path: utzoo!utgpu!watmath!att!dptg!rutgers!gatech!prism!bb16
From: bb16@prism.gatech.EDU (BOSTATER,Scott)
Newsgroups: comp.sys.ibm.pc
Subject: Re: backup programs, DMA speeds
Summary: DMA Chip replacement
Message-ID: <1674@hydra.gatech.EDU>
Date: 30 Aug 89 16:41:03 GMT
References: <8Yym5V200WB58jE1Az@andrew.cmu.edu> <4048@csd4.csd.uwm.edu>
Organization: Georgia Institute of Technology
Lines: 28

In article <4048@csd4.csd.uwm.edu>, burkett@csd4.csd.uwm.edu (Edward W Burkett) writes:
> I have one of those clones (LE Model D) that have a bad DMA.  

                 [stuff deleted]

> I would like to replace the defective chip but I need to know more about its
> location.  Is the DMA chip part of the mother board, floppy disk controller or
> harddisk controller.  I assume it is on the mother board.  Secondly, can it be
> easily purchased and replace by the owner or would it have to be put in by a
> repair technician?
> 
The DMA chip is on the motherboard. (At least it is on the original PC/XT/AT's
and most clones). What you would want to replace is the Intel 8237 High 
Performance Programmable DMA Controller chip. Chances are that its solderd
directly to the motherboard. Its a 40 pin chip so unless you have the proper
hardware to desolder that large a chip, a PC technician might be a good 
investment. You could cut the leads off the chip and unsolder each pin 
individually, but that topic has already been discussed in 
comp.hardware.mutilation :)

As far as the location of the chip, It should be the only 8237 on the board,
happy hunting :)

-- 
Scott Bostater      GTRI/RAIL/RAD   (Ga. Tech)
"My soul finds rest in God alone; my salvation comes from Him"  -Ps 62.1
uucp:     ...!{allegra,amd,hplabs,ut-ngp}!gatech!prism!bb16
Internet: bb16@prism.gatech.edu