STe - Bad DMA Chip

[blackpanther]

Hi all!

Just joined the Forum as I got my first Atari STe last month and was hoping someone here could help me. I recently found out that my STe has a bad DMA chip and with the ultrasatan soon to be finished I want to try and sort this out before I recieve it.

I do have a STFM and was wondering if it was possible to use the DMA chip from that? If not does anyone no where I can buy one?

Thanks
Mark

[MRAtari]

you can't use the DMA from an STFM

but i do have a few used GOOD DMA chips left so you may be in luck

they are £10 each plus postage

PM me if interested

[blackpanther]

PM sent! Many thanks for your help.

[Decky]

Surely the STFM would have an earlier DMA chip than the later STE models anyway, thus containing the bad DMA chip? I have three ST/FMs and they all contain the BAD DMA chip, but they also have low TOS versions, which I don't think could be upgraded! I use em for games only, and any serious stuff is done on my STe, with good DMA, external HD and switchable 1.62/2.06 TOS!

[Frank B]

Surely the STFM would have an earlier DMA chip than the later STE models anyway, thus containing the bad DMA chip? I have three ST/FMs and they all contain the BAD DMA chip, but they also have low TOS versions, which I don't think could be upgraded! I use em for games only, and any serious stuff is done on my STe, with good DMA, external HD and switchable 1.62/2.06 TOS!

I have an early STE which I bought in march 1990. It has TOS 1.6 burned onto EPROMS on it. It must be one of the earlier batches with the defective chip. I've never had any issue with it using 2 different hard disks. YMMV

Frank

[MRAtari]

i'm sure the issue had been sorted by march 1990

[Frank B]

i'm sure the issue had been sorted by march 1990

The STE had just gone on sale in the UK. The ROMS are dated late 1989 and contain the med res bug. I bought mine sometime between the 11 and the 13th of March 1990. Anybody else bought and STE prior to this date or had offical labeled EPROMS in their machines? It would be good to know which machines are affected. I reckon mine was one of the first batch to hit the UK.

[Nikolas]

Dont be so rlly shure if dma chip died..if you havent try to replace, ofc.

I use to believe shifter gone bad, but glue die in st..
Idunno maybe you need help some one who got some parts and sell it to you, or send to someone who can fix it..

[spiny]

can someone remind me how to check for a 'bad' dma chip, cheers

[MRAtari]

there is ONLY one way i'm afraid

and that's take the lid off, undo the 3 x floppy drive screws, lift up the drive and the DMA chip will be underneath the floppy

look at the numbers on the chip from the numerous posts about this now to tell if you're is good or bad

NB: later type STE mobo's from late 1991 had a different DMA chip which was a small square type, completely different in shape from the older type and this type was surface mounted too

if you have one of those then no need to read the numbers as it will defo be a good one

[spiny]

look at the numbers on the chip from the numerous posts about this now to tell if you're is good or bad

yes, thats the info I need, I appear to be failing at search today

[The following words in your search query were ignored because they are too common words: ste dma.
You must specify at least one word to search for. Each word must consist of at least 4 characters and must not contain more than 14 characters excluding wildcards.]


I have (I think this is the right chip):

9017 NCF
C398739-001
(C) ATARI 1989
-31 160511-01

[spiny]

a pic is probably clearer

[MRAtari]

yep - that's a good one

info below for anyone who needs it:



1.f you find a chip marked as follows you're OK and can go ahead with a harddisk:
C398739-001A (Atari-1990)-31

However, if you find a chip marked with the numbers below you have a damaged DMA chip and need to get a new one before attempting to use a harddisk via an SCSI host-adapter:
C025913-38 PH23-001A

[spiny]

sweet, so even though I don't have the 'A' suffix, it's still ok ?

I just need a psu, floppy drive, ram, keyboard and a case lid and I'll be ready to roll

[MRAtari]

the important part of the number is C398739-001 - this is the good chip

all the other bits vary (interesting that yours has the 1989 date on it)

the numbers 9017 is the date which is week 17 1990 which is the first week of May 1990 hence me thinking this was sorted by early 1990

in my experience of STE mobos the first dates you'll see on very early ones start at week 30 ish 1989 which is around August time, the earliest will have SIPPS too instead of SIMMS

most mobos i've seen with any 1990 dates on them have the revised chip, therefore i'm guessing this problem only applied to the first 6 - 9 months of production of the STE

[spiny]

the important part of the number is C398739-001 - this is the good chip

all the other bits vary (interesting that yours has the 1989 date on it)

the numbers 9017 is the date which is week 17 1990 which is the first week of May 1990 hence me thinking this was sorted by early 1990

in my experience of STE mobos the first dates you'll see on very early ones start at week 30 ish 1989 which is around August time, the earliest will have SIPPS too instead of SIMMS

most mobos i've seen with any 1990 dates on them have the revised chip, therefore i'm guessing this problem only applied to the first 6 - 9 months of production of the STE

good info, thanks that particular board is, I think, marked Rev A, 1989, but I'll take a photo later when I get home.

[Shredder11]

the important part of the number is C398739-001 - this is the good chip

all the other bits vary (interesting that yours has the 1989 date on it)

the numbers 9017 is the date which is week 17 1990 which is the first week of May 1990 hence me thinking this was sorted by early 1990

in my experience of STE mobos the first dates you'll see on very early ones start at week 30 ish 1989 which is around August time, the earliest will have SIPPS too instead of SIMMS

most mobos i've seen with any 1990 dates on them have the revised chip, therefore i'm guessing this problem only applied to the first 6 - 9 months of production of the STE

Interesting! My main STe has a C398739-001A and the number above for the date is 9135 LGA. I don't know what the bottom row of numbers represent, -31 I60511-01.

[spiny]

some pics ... mine doesn't have a 'rev' letter, I think i must e thinking of one of my other ataris.

[MRAtari]

well there is your proof then that by early to mid 1990 the issue had been solved

PS: looks like those TOS roms soldered directly to your board Spiny are TOS 1.06 ...

[MRAtari]

i'm sure the issue had been sorted by march 1990

The STE had just gone on sale in the UK. The ROMS are dated late 1989 and contain the med res bug. I bought mine sometime between the 11 and the 13th of March 1990. Anybody else bought and STE prior to this date or had offical labeled EPROMS in their machines? It would be good to know which machines are affected. I reckon mine was one of the first batch to hit the UK.

the STE was released in late 1989 in time for xmas...

[spiny]

well there is your proof then that by early to mid 1990 the issue had been solved

PS: looks like those TOS roms soldered directly to your board Spiny are TOS 1.06 ...

closer pic:



I'd like to upgrade to 2.06 at some point, as this machine has the 'med res' bug, but i've started a topic on another thread about that

[MRAtari]

remove the roms and solder in 2 x sockets

remember to use 32 pin sockets and not 28 pin like your 2 x roms

you'll have to move the jumpers in front of the roms to for any tos roms that are 32 pin

[spiny]

are these the correct size ?

http://cgi.ebay.co.uk/6-x-SOCKETS-DIL-I ... 1|294%3A50

[spiny]

and I'll need some of these too, I presume ?

http://cgi.ebay.co.uk/2-x-Connector-Str ... 1|294%3A50

[MRAtari]

yep those are the correct sockets

you don't need the other bits unless you want to use them, all i do is move the original resistor on the board