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Dos Issue...I think !!!

C

canuck46

Experienced Member
Joined
Mar 20, 2006
Messages
86
Location
Chilliwack,BC,Canada eh
So,I have a IBM 5150 which runs perfect.....has 10 mg Hard Drive...running Dos 3.3. The other day when I started it up.......Instead of going directly to "C" prompt....it prints the line......" f600 ROM" then the "C" prompt.......?????? Runs perfect otherwise???? checked all cables ,plugs etc. Even re-wrote autoexec, but to no avail !!!!! Anyone got any ideas? I have changed "NOTHING" on this computer in months.....just started with this message a couple of days ago.

HEEELP:confused:
 
Damn, just when you were beginning to redeem yourself!
Focus on the V-C forum game, it showz off your inate intelligence & creativity so much better than replying to vintage computer qwestionz in which you have too little experience to contribute anything meaningful.
BTW, take this as a left-handed compliment...I really like where you're going with the game. If you have any specific questions about early systems, don't be bashful about asking.

--T
 
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Its Running Again...

Its Running Again...

Actually,always was running....just had error code....(see first post). Anyways,Running PERFECT now !!!!!! Took Lukes advice.....went and checked out error codes etc. I striped out Daughter Cards etc...and what ever was in the way......got out my handy dandy little book of chip locations.....found U29.....cleaned up whole Motherboard....removed chip and replaced it after cleaning iit up(along with socket(?).put it all back together....same problem !!! SOo....went down to my workshop.....dug out my "Parts" machine.....poped out U29....cleaned it up...Installed it my "Baby" and IT WORKS PERFECT! So my parts machine now needs a U29 chip..... I put the BAD one in just to see what happened.....It now has error code....So,I guess I'll be lookin for a U29 Chip sooner or later.....Thanx Again Luke.:D
 
No problem, just googled a bit.

Wow, this chip isn't BASIC, this is BIOS...
How it can run with BIOS damaged?
 
Part of the BASIC interpreter is in the BIOS chips of the machine ..

For anybody who wants a good overview of how an IBM PC works, get Peter Norton's 'Inside the IBM PC'. It explains all of this stuff.
 
atari2600a said:
I didn't even know bitrot was even possible on a ROM...
Click to expand...

OK, let's call it 'old age' then...or ROM-Alzheimer's...or just plain ol' physical deterioration (an internal breakage of one or more of the physical connections, which has the same effect as if the connection were 'blown' on purpose)...

--T
 
Yes, but ROM's are virtually indestructable! A ROM can be run over by a vehicle many times, placed in boiling water & in freezing ice, be burned over an open flame, & it would still work!

EDIT: Plus, the silicon wafer is incased in molten plastic during manufacturing. It's kinda hard for something to break if there's absolutely no room for movement...
 
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But, PROMs do go bad sometimez, that's the point. Mebbe the bond of the plastic (or ceramic) to the metal parts sticking out from them is less than perfect, allowing moisture to seep in over the yearz till corrosion takes out a joint? Mebbe it's a minute flaw in the silicon? Mebbe it's just KozmikDebris that flips over a bit...who knowz? (Where's those damn gremlinz when ya need 'em?)...

--T
 
ROMs are pretty fragile when they are old. In my Epson AX2e (a 1989 286) the BIOS ROM has physically snapped in half - the top layer or the ROM casing has detatched, exposing the chip. Needless to say, it no longer works...
 
Corrosion isn't the only culprit that can do this sort of thing. Oxidation of the metal pins themself is sometimes the fault.
I usually run the flat edge of the chip lightly over a VERY fine sanding block (exterior and interior surfaces) and then scrub out the socket several times with component cleaner and an old toothbrush with the bristles cut down to 5mm.

In the majority of cases, that does the trick. In touch cases, you may have to use a fine slot jeweller's screwdriver to clean up the wipes on the socket while the contact cleaner is still in there.

It's worked for me, but, be gentle with the sanding block, especially on old chips, just a light swipe in each direction.
 
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