Jump to content

1050's Photo


Member Since 24 May 2007
OFFLINE Last Active Today, 3:36 PM

#3908811 rom to exe

Posted by 1050 on Yesterday, 3:43 PM

A real machine would have a major headache trying to
emulate a bank switching cart like BASIC XL. The
only reason it runs on emulators is because the
emulator has that extra code and storage place to
emulate the bank switching cart with, the real
machine has only the cartridge hardware and it's

Method might be better done with reverse order.
DOS is booted which then goes looking for
AUTORUN.SYS file(s) which then load the cart
data. Files such as AUTORUN.SYS have headers that
tell DOS where to place the code while having
two unique places to RUN or INIT the loaded code.
INIT address of 0x02E2, 0x02E3 is always run as
soon as it is changed from RTS address pointed to
by DOS as it loads memory as told to by the header.
This is why AUTORUN.SYS files should only be using
INIT address to run code and should always end with
RTS instruction so that DOS will just resume loading
the rest of the AUTORUN.SYS file. And this means
AUTORUN.SYS files can be appended to do things in
desired order. RUN address 0x02E0, 0x02E1 is jumped
to only after the file is finished loading and
IOCB is closed.

pg 65,66 --- pdf pg 99,100

Cartridge also has INIT and RUN address but at the
end of the cartridge space.
Mapping the Atari
pg 103,104 --- pdf pg 137,138

Executable files always start with FF, FF double
bytes to indicate an executable file follows.
Load to address pair comes next followed by ending
address pair to load data to. Double FF can be repeated,
which will be ignored as next in the file structure
and/or you can have just another pair of load addresses,
start and end. And this pattern can go on as many
times as you need it to. RUN Address can be changed
many times but the only one that is RUN is the last one
It would be a headache WITH the real BASIC XL cart,
without it, I have serious doubts it can be done
on a real machine at all. You would need to write a
custom banking system that used extended memory to hold
the bank switched cart data and then move it along
with changed banking address that is looked at every
interrupt to see if a new bank is supposed to be
there or not. Pure hell if you ask me so I really
doubt anyone, if they have written such a thing, is
here and now to give it away.

So very much easier to get a real BASIC XL cart.
And then start pulling the hair out getting
AUTORUN.SYS to play nice.

Welcome back BTW, nice when that happens.

#3899741 Requesting Help identifying an Atari 800 RAM upgrade

Posted by 1050 on Tue Nov 28, 2017 11:51 AM

Thanks, Claus.
My bad in post #8, I have been misreading the 800XL
schematic in the wrong manner all these years then
and it's just a happy co-inkydink that pin 7 for
that 138 is D7xx just as it is here. The Byrd has
a single wire from Z401 pin 7 thru the hole to that
card slot edge as pictured here.

And that means I can convert mine to be a real
Axlon following this example. I'll be doing just
that someday then. Thanks for posting the excellent
how to do it pictures John.

Original schematic along with Sams Photofact


Jerzy Sobola

#3899581 Atari 800XL OS programmers name in rom?

Posted by 1050 on Tue Nov 28, 2017 4:26 AM

Other possibles depending on what OS you were running
might be MARSLETT, Bob Puff, Robert Puff, C HAMLIN.

#3890898 Half Dead Atari 65 XE?

Posted by 1050 on Wed Nov 15, 2017 9:30 AM

That's good news. A friend with a voltmeter is a very
handy friend to have sometimes. :)

#3890822 Half Dead Atari 65 XE?

Posted by 1050 on Wed Nov 15, 2017 6:40 AM

Oh yeah, plenty of people have very similar symptoms.

First thing you should do is measure the power output
of the power supply to eliminate it as a serial computer
killer. It is a common problem.

In the meantime don't plug it into anything valuable
until you get a voltmeter and can measure the voltage it

If it is bad, you'll need to replace it with a good one
so the voltmeter will come in handy testing the replacement
first as well.

Your supply might be fine and it was another power supply
that went bad and ruined one or more RAM chips by shorting
them out from excess voltage from the bad power supply.
It is such a common thing to happen one really needs to start
here first.

Watch how Jon uses alcohol spray to find his extra hot
Ram chips in this video. The shorted RAM chips will run
extra hot and can just be replaced to get a completely
working fine computer again.

If your power supply voltage is near 5 volts and your RAM
chips evaporate the alcohol at about the same rate, then
we can begin to explore other issues with the use of special
carts and other avenues. Are you comfortable using a
voltmeter and/or soldering iron?

#3888558 Atari 130xe video issue

Posted by 1050 on Sat Nov 11, 2017 5:50 PM

Screenshot #2 shows self test in music mode so BTDT.

I've seen such garbage characters corrected by dropping
in a HCT08 for the standard 74LS08 at U18. This tells
me that it's something to do with timing and/or not so
square edges on system clock signals. Ram is of course
also involved but the root issue is the system timing
is tad bit off by perhaps a weak LS08 chip. One could
piggyback one onto U18 if it weren't for the useless
factory mod involving the pink and purple wires getting
in the way there. Just as a temporary test of course,
good results would dictate a proper entire replacement

You could even remove the factory patch pink and purple
wires by restoring a cut trace on the bottom side of the
board and tossing these famous wires in the bin. It won't
make a hill of beans difference either way. It's GTIA's
chip select signal from the MMU IIRC.

I've never had to put one back whenever I've taken the time
to remove that factory patch. Highly suspect that management
made this fix up just to keep the repair team busy with
work stacked to the ceiling instead of letting them sit
around reading novels and having food fights.

#3884967 400 woahs

Posted by 1050 on Mon Nov 6, 2017 1:27 PM

Woe Nelly, woe.

#3880986 Power Supplies....

Posted by 1050 on Tue Oct 31, 2017 8:47 PM

Because the wattage issue expressed as VA is still
so close to right that it doesn't matter which one
is used for the device. One type of device uses 9
VAC and the other 5 VDC which are the two main
differences to keep in mind.

And not a dumb question at all, I wish more people
would pony up and ask about issues that just aren't
gelling for them. It's exactly how we all learn, each
with our own confusions that need addressed before we
can move on to the next issue. And you may get a much
better answer from the next guy since he thinks more
like you do and then explains it in a way that is
easier to accept.

#3869768 Failing PSU's, what do they put out ?

Posted by 1050 on Tue Oct 17, 2017 5:32 AM

It's surprising they used locktite on the nut on the other side though...maybe it's just factory left-over.

Youngsters, what are you going to do with them?

They were using fingernail polish for that work
before I was born. And locktite didn't exist.
This is before the beetles just in case you are
wondering. And yeah, Elvis was king. Not that I'm
a fan.

Try and buy some fingernail polish that ISN'T
colored. Then endure the funny looks you get
when you finally have settled on a color that
is acceptable. You guys have not paid your

#3860776 Newell OSN for 400/800

Posted by 1050 on Wed Oct 4, 2017 7:43 AM

Your order is somewhat whacked, but I can
understand how easy that can happen so no

So Fastchip is different from Fast Chip and
they work differently too. Marslett wrote
Fastchip and it's a replacement for the
standard FP math pack rom that lives at
D800-DFFF. Fast Chip is something else
that also occupies that region as well as
C000-CFFF - this one has no source, can't
find much about it and have nothing to
gauge it's speed by in the first place.
  • Omni something C000-CFFF
  • empty/zero D000-D800 (hardware registers)
  • Fastchip D800-DFFF
Is how it should be set up for the new 400 card.
Not sure where I got the ramrod OSN that the
attached burnfile contains but am thinking it
was posted in this group on the subject of the
ramrod board. It appears to contain the 8K omni
though which would require active eprom addressing
scheme and that part is unknown to me since I
don't have one of the ramrod boards set up for an
8k omni - I say that only because I don't know if
it's a combo monitor/80 column viewer and it sure
could be both. The source code for OSN calls for
OMNI only as if both are fired up with a jump to
CFF5 from OSN code. But the ramrod code I have,
has garbage there, so it's NOT clear at all if
the OSN offering here will actually work or not.
Since no emulator allows Cxxx rom, there can be
no test there that will work, it must be done
with the new 400 rom card.

So the first half is OSN as found on the ramrod
code and the second half is standard OS B and
you'll have to fire up Omnimon via a jump to
CFF5 which inserts it's interrupt vectors into
the interrupt table such that it should work
with normal keypresses for Omnimon from then
on? At least that's the hope I have.

So find enclosed what I have at the moment,
a nebulous OSN which I believe to be version
4 since it's a bit different than the version
601 source code recently found. My own Omin800
rom which was found in an 800 haul as a dismounted
eprom in a film can with nothing but a label to
tell me of what it was. No other documentation
was ever uncovered about it. I did get a ramrod
user to come back and say 'thanks, it worked a treat.'
So there is that much, and it does have working code
at CFF5 that does insert interrupt vectors and set
about to 'live' large - the 8k version in the ramrod
image had garbage there and not sure what to make of it.

So the DOS mode copy file1+file2 file3 method needs the
/b switch slapped up side it's head or you'll get short
builds that can't possibly work right. Enclosed find the
copy.txt that has added at the bottom the useage I used
to build the burnfile from all the parts I've been able
to gather. So now you can build it in reverse order if
that is what you want too. Make copy.txt like this:
copy /?>copy.txt
Attached File  burnfile.zip   29.79KB   10 downloads

I am working on OSN version 601 but the results are
lacking the proper power up sequence. It wants to
set up interrupt vectors via OMNI branch to CFF5
before the ram has even been cleared and the OS
system properly installed. Unless Newell decided
to just plug in the proper powerup vector at FFFC
as an afterthought rather than have the code assemble
in that manner? I have more work to do in other words,
this is what I gots right now. It's likely there will
be other issues with 601 too.
  • slx likes this

#3858395 1050 write protect jumpers J5, J6 and J7

Posted by 1050 on Sat Sep 30, 2017 7:01 PM

Schematic is wrong, pin 12 of U11 is grounded with
extreme prejudice. Blob O solder on pins 11 and 12
on the bottom side would do the trick then, but I
would pull jumpers 5, 6 and 7 for the next guy to
stop and wonder long enough perhaps to spot the

#3854208 Atari 1050 disk drive not detected?

Posted by 1050 on Sun Sep 24, 2017 3:05 AM

Good news, glad to hear it too. Don't know why those 3086
are so common to go bad, but the other one will do it too.
It won't format if it goes bad, but will read fine in that

So you should try some soldering flux on that corrosion or
even a small wire brush gently until the board will take
solder well. Then you can lay down solder where the
corrosion was to sort of bridge the rough spots over for
electron flow. May need to do all three at the same time,
solder, flux and wire brushing. Don't forget to clean up
that flux when done too. 90% or better isopropyl alcohol
please. You may need to go down several pharmacy section
isles in the various stores around you to find it, but
it's there. 50% rubbing alcohol is just not strong enough
so don't settle - keep looking instead.

There are two diodes CR15, CR16 (1N4001) in between
two of the big caps that should be re-installed where they
stand up off the board so air can get to them and cool
them. I've got one board ruined because Atari was cutting
their legs off and mounting them right down on the board.
Two burnt spots right there - they run HOT, so Atari
started placing them with uncut legs way up in the air
where they worked out fine. These are the two diodes
supplying 12 volts for the motors. I would look to the
12 volt supply since it got overtaxed with the stuck
disc. That could have damaged Q8, the 7812 voltage
regulator for the 12 volt system. It's mounted to the
huge wrap around aluminum heat sink over by the power
jack, front side leg should read up to 22 volts DC
and the heat sink/power jack side leg should read right
near 12 volts under load (motors turning with disc in
drive) or unloaded both.

You might want to consider doing away with the heat
producing series type regulators (7805 and 7812) for
switching ones pointed to in this post.

The four big diodes in the corner are for the 5 volt
system and are usually fine, but I've seen them go
bad too. Usually when one of these fail the drive
will barely show a power light and do little to
nothing else. These are MR501 diodes 3 amp, 100 volt
and anything meeting or exceeding those ratings
would work. 1N4001 is one amp, 50 volt rated, same
story there anything better will do. Older part
numbers are obsolete and data sheets warn 'Not for
new designs'.

Start with voltage measurement of both regulators,
replace CR15 and CR16 just because it's a good
idea to get them up off that board if that's where
they are now and expect Q8 the 12 volt 7812 to be
in a very sour mood. If you don't have the high
DC voltage then the problem is likely due to the
corrosion you mentioned. 22 volts down to 17 volts
would be ideal for the input side of that regulator.
It has to be at least 2 volts over the regulated
voltage in order for the regulator to actually
work, and if you only have 14 volts then the problem
is likely to be on the supply side, corrosion,
faulty solder to the legs of the big caps, etc.
Low supply voltage might also be a shorted Q8 dumping
everything it can eat, but it should be running
very hot while doing so, even boiling a drop of
water placed on it. That's usually when the magic
smoke gets turned loose and without that stuff in
there, they just up and quit.

Bare copper wire can work to repair broken or
crappy traces alike, just lay it down where the trace
was and apply solder. Flux helps very, very much.
And the copper traces and/or wire should be very
shiny even if it's from being scraped with a knife
edge, done carefully of course.

#3848843 Simple way to test 4164/41256 chips?

Posted by 1050 on Fri Sep 15, 2017 11:22 AM

I purchased a similar board at an outfit called OEM
locally, they specialize in hoarding throw away
electronic gear and looking up the NEW price and
then inflating that to be your price. For some
unknown reason this one was just a few bucks and
had so many ram chips I could use I pony up the

Just my opinion, I don't think it's much of an
issue. Use them as needed, there are only two
types, those that will and those that won't.
I wouldn't bother with a tester unless I was
looking for something along the lines of say
a SALT test which can find the bad one or Jurgen's
Sys-Check which seems capable of doing the same
thing and much, much more. Please take a look
at page five of the manual before attempting to
re-invent the wheel.

You might find that the included toys in Jurgen's
test board are worth having around like I did. All
I need now is an Atari that doesn't work.

#3840162 Atari 1050 disk drive not detected?

Posted by 1050 on Sun Sep 3, 2017 4:23 AM

A good switch cleaning requires something like like
deoxit, but to be done properly the switch also
needs to be worked vigorously while the switch
contacts are wet with the cleaning solution.

Working the switch dry doesn't work any better than
just spraying the unworked switch with the best
juice possible is my only point. Vigorously isn't
to taken to dangerous level, just ten or more
position changes. Generic FYI for everybody, along
with WD-40 will work for this use too.

I suspect U1 3086 transistor array is blowing
out the SIO comms with a shorted transistor on
the command line perhaps. I would just replace
both 3086 chips and with no joy there, then start
swapping out large count socketed chips until the
problem moved with the bad chip. It does sound like
something is certainly very ill with this one,
best of luck.

#3838146 Atari max 1200xl and Happy 1050

Posted by 1050 on Wed Aug 30, 2017 7:37 PM

Might need to do the R63 delete on your 1200XL?


Shows R63 replaced by a wire jumper pointed to by a
wooden skewer. This resistor caused mine to not work
with any 1050 and I just jumpered it without removing
it which is another option. It's a very common thing
to have to do.

Alligator clips with wire between them would temporarily
show you if this is the actual issue or not. Before
modding anything too.