| Attachment | Size |
|---|---|
 Mod on side board - front | 439.29 KB |
| Mod on side board - middle | 507.92 KB |
| Mod on side board - rear | 558.63 KB |
Hello Apple II enthusiasts,
as this is my very first post here, I want to express my thanks for all the helpful information.
I want to request your thoughts on a heavily modified early Apple II that I recently obtained. This particular Apple II came from the Netherland and I think it has an interesting mod. This Apple needs some TLC and I have not tried yet to power it up. I would appreciate your highly welcome input to point me into the right direction on what to do with it...
The first and former owner passed away and I have no chance to find out more about the history of this computer.
I have no idea about the origin of this mod and hope to find out something about it. The former owner was a highly educated person and might have done the mod for his own needs - but I doubt because a printed circuit board has been fitted especially into the case. Maybe there were more mods like these well known to the experts???
My initial idea/intention was to restore (or better let restore) to factory condition and remove all the mods but I'm not so sure now. It appears this was done shortly after the computer was build and I think it might be better (but more difficult because undocumented?) to try to resurrect and keep her as is. Maybe there were already many early apple II in pristine factory original condition but not so many with this mod that might document the early attempts to place Apple II on the EU market.
Even if the mod is only "homebrew", it looks very complex to me. Maybe there is an interesting story behind it? (early EuroApple? early dealer option/attempt for the EU market?) So it might be worth the effort to keep the mod in place?
Here are some first pictures, I will add more when I have removed the case and have better access to show more details.
Thanks for your input in advance.
Hello Applebox83,
welcome in the community...
the pictures are very interesting but unfortunatly not complete for
estimating correct the entire functions of the mod....
for example at IMG_6939 at the right side the 2 wires leading to source outside of the picture....
to judge the function it would be needed to recognize the source where they come from....
Also it would be usefull to get a view of the entire mainboard....
Up to the moment the following guesses ( without confirmation due to missing pictures ):
It seems that this is a US-model NTSC Apple ( not confirmed yet due to missing total view )
that has been modified very professional to european PAL standard by a technichian
that has very sophisticated knowledge to both standards....
this modification is far beyond what is normaly called "homebrew"....
and it´s first time i´ve seen this very kind of modification
( and i have seen several hundreds of Apple II computers here in Germany ).
For better analysis several more pictures would be needed....
i guess this mainboard is a revision before the RFI mainboard has been released,
because later Apple released a PAL version of the Apple II called the
"Apple II europlus". But this can only be confirmed if we can see the datecode
in the left rear part close to the powerconnector..... and the general layout and markings of the board....
it also makes sense to add a picture of the serial label at the bottomside of the bottom plate....
due to the fact that the UHF modulator is within the mod you may assume that this model
should have rather good display at a television set ( somewhere in UHF Band between channel 34 and channel 45 )
and the skill of this mod lets me guess that this model has excellent display of the real colors at the TV.
Bear in mind that the Apple II had slight shifting besides of the real standards and therefor
in general Apple II Models display in Europe only rather poor the colors at a TV set. But in this case it
seems that the owner realy made a modification by even generating the original timingclock
to be used for PAL signals at the mod board and then adding up the videoinformation to that
basetiming....
That´s also the reason i claim this mod to be far beyond what in general is called "homebrew" ....
speedyG
Hello Applebox83,
congratulations! It looks you have a rev.0 motherboard (no transistor near location F-13 for color killer circuit).
Information at excellent Mike Willegals site - http://www.willegal.net/appleii/appleii-recreation.htm
The mod does not look "homebrew" as speedyG noted - the board has solder mask and some part number.
My advise is not to hurry with anything. Rev.0 boards are not common.
More pictures are welcome
Stefan
Thanks for the interesting first feedback!
I've uploaded all my photos to flickr. I've removed the case and also the PSU (that is obviously a later model that has been converted to 220V). So in the album the later photos do show more details as requested.
I have tried to decode and document as good as I can in the photo titles and descriptions. Feel free to add your comments below the photos or here in this thread.
Maybe I made some mistakes in the photo description (i.e. I'm not sure what's going on with that unusual ROM setup). I will try to fix those according to your input.
https://www.flickr.com/photos/lars-schenk/sets/72157659882852928
(I have not uploaded directly to the forum because of the size and many photos that I've already uploaded and maybe I'll add more photos to that album later - i.e. keyboard; datestamps etc..)
I look forward to your highly welcome informations and advices.
Hi applebox83,
there is at least one big mistake in the computer:
at location of the D0 ROM there is a F8 ROM inserted....
instead thats the location where normaly the Programmers Aid ROM is installed.
and at position of the F8 ROM there is the Programmers Aid ROM
that is intended to be inserted at Position of the D0 ROM !
So this 2 ROMs must be swapped before performing a power on !
Adding 2 other damages to the list after view of the pictures:
The 27µH inductor at Position F14 is destroyed ( cracked ) - usualy a damage
caused by shortcut and heat... it must be replaced !
The 74LS161 at position D3 has heavy oxidated legs ! This surely will cause serious problems at the display...
It´s highly recommended to remove the oxydation and reseating that chip or even replacing and to try remove oxydation
inside of the socket.... maybe use of cotact spray will be required after removing the oxydation.
similar is valid to the chips at location J1 and H2 and C2 and B4 ....
a final remark for the moment:
some pictures of the slots display crumbles and similar stuff at or in the slots....
please inspect before you power on that system also carefully
that slots and remove dirt or similar stuff from inside...
some stuff may cause shortcuts or damage if remaining in that slots......
sincerely speedyG
Thanks again SpeedyG for the important hints!
Photos in the fllickr album are sorted by date. Oldest first. Older photos I show the condition as I got the computer (very dirty).
So here is my todo list before I dare to power her up with a tested PSU.
I'll clean very carefully (with isopropyl alcohol) and make sure there will be no electrical shorts in the slots.
I'll reseat all ICs and make sure there is no oxidation/dirt.
I'll replace cracked 27µH inductor at F14. Maybe it's impossible to find optical identical 27µH inductor
I'll remove ROMs, RAMs and CPU check for correct voltages before I but them back. Hope this is a reasonable method to avoid further damage.
I'll check with infrared thermometer for any hot spots and I will apply power only for a short time at first.
I'll start with tested RAM, Applesoft ROM and tested CPU next to keep the original set safe at first.
(optional if possible: I'll start with complete set of ICs from tested board - maybe use ICs from RFI board as much as is compatible - this might save the original old ICs and might make it easier to find bugs).
Regarding the strange ROM setup:
As you might have read in my picture descriptions, I totally agree that something is wrong there. Your observation / conclusion is that F8 and D0 has been simply swapped (Monitor/start ROM in D0 and Programmer Aid in F8). I think that is NOT the case.
Actually there are two F8 ROMs installed (and there is no programmers aid ROM).
In F8 is the later Applesoft F8 Rom and in D8 is the early integer F8 ROM.
The board has the integer ROM set that should be installed correctly like this:
F8: C38012 A1MB-F8
F0: C38011 A1MB-F0
E8: C38010 A1MB-E8
E0: C38009 A1MB-E0
But currently I find the C38012 A1MB-F8 ROM in the D0 slot while in the F8 slot has the Applesoft F8 Autostart ROM installed. (this is assumed to be an error and not on purpose).
This makes me wonder why this was done. Maybe the computer did not boot and someone just tried to use a F8 Rom from Applesoft. (and to keep the integer basic F8 ROM in the computer they just put that in the D0 slot?) I assume it's not possible to make it work with a mix like that. So it's totally nonsense the way it is and I'll start with a testet Applesoft ROM set for debugging purposes and easier start. (And later try the Integer ROMS in correct positions).
My basic idea is to start with as many "known good" components as possible to avoid complex trouble situations and to save the original old parts for eventually further damage.
While cleaning the board, and all legs and slots I'll also check for further optical damages because I already found a yellow wire that has come lose - easy to fix and thankfully no doubt where it belongs...
Are there any more precautions that I can/should take to keep possible damage low when put the machine on power again?
I'll keep this thread updated and will also add more photos to the album - but it'll take some time - it's a spare time project and I'm learning.
Meanwhile it would be great to find out if there were any known specifications available for the board at the side.
I found this document - but that does apply to a later board as I understand it.
ftp://ftp.apple.asimov.net/pub/apple_II/documentation/misc/APPLE%202%20EURO%20APPLE%20MODS.pdf
Hello Applebox83,
you´re correct mentioning the ROM´s.
It seems by description, that the current status is explained in the
Euro Mod description at page 14 section:
Mod 3 Part 2 processor ( ROM mod )
providing the user with the ability to switch between the 2 different
F8 ROMs.
Besides reading this summary of the former Euro Mod description should
lead to the conclusion not performing a move back to NTSC system.....
There are that many cuts in traces on top ( below the sockets ) and the bottom
that you would need at least a day to mend the cutted traces and stepping back
step by step.
The complexity of that mods will show also at the solderside of the mainboard
displaying bunches of wirebridges at the bottom side.....
speedyG
Wow!
This is a very different kind of II.
I have never seen one like it.
Nice!
Steven
It that PAL Converter works very well, it might be worth Cloning for others needing to have PAL output with NTSC Computers...
MarkO
Hello Mark,
did you view the document listed in the last line of message #5 ?
You have to perform more than 20 trace cuts at the mainboard.....
( some even below sockets after lifting them up and then after cutting
seating them back down... ) This mod is nearly unrecoverable ...
nearly no chance to go back to former condition....
speedyG
Sorry... I did not look at the details...
Your Right!!! This would be Very Difficult to install for the Average Apple ][ Owner....
MarkO
I had linked to this document
ftp://ftp.apple.asimov.net/pub/apple_II/documentation/misc/APPLE%202%20EURO%20APPLE%20MODS.pdf
because it was the closest I could find. But as stated before I do not believe that this is a perfectly matching documentation for the mods applied to A2S1-2333.
a) Title is "Conversion of Apple PCB #820-0014-01 18/02/83 For NTSC Color Video Output"
I think #820-0014-01 is partnumber for Rev 1 boards? But A2S1-2333 is a rev 0 board.
b) The document is dated 1983. But the mod on A2S1-2333 has been done earlier I think.
c) "PAL color adaptor board" is mentioned but not shown or described anywhere. I don't think this "PAL color adaptor board" is the same as found at the side of A2S1-2333.
Maybe the document is more showing how to convert an earlier Apple II with the later PAL board that was avialable for the Apple II Europlus?
d) Other modes (Upper & Lowercase Mod) were described in the document that have not been applied to A2S1-2333.
e) It appears to me that the document is just not compatible with the mods that I can see on A2S1-2333.
As a result I can't yet confirm that the modifications and the cuts described in that document have been applied to A2S1-2333.
I will hopefully make some photos of the rear side of the board soon. So someone can compare and we can see what cuts have been made.
Now a short update on the current status (very slow progress):
I have added 16 new photos to the flickr album:
https://www.flickr.com/photos/lars-schenk/albums/72157659882852928
I was testing PSU and keyboard with another good Apple II logic board.
Fixed the (later) PSU (had cracked/burned filter). Will use it as a temporary solution but I'm looking for a more authentic PSU for this machine.
Diagnosed the keyboard: Found connector cable was attached wrong and maybe has caused damage. The connector has been moved one row to the right. I think this has damaged the keyboard. Maybe I need a new encoder MM5740AAE/N - maybe even more?
Has anybody info what happens when the connector is moved one pin to the right like this has happened here obviously.
I noticed before I did power on - but I have to assume that the keyboard got power this way (with false connection) at previous owner. So I have to assume the worst.
I've checked with the pin out: The -12V goes to "not connected" (luck!) but the +5V goes to strobe - and I think that might cause damage, right?
http://bit.ly/1iDQBet
Current status of keyboard when connected correct: Power light working (yeah!) and the reset key is working. All other keys are dead. Some are mechanically sticking (minor; fixable - work in progress..).
Looking for a good known MM5740AAE/N....
Cleaning the logic board, sockets and IC legs (corrosion) in progress... Not yet tried to power it up! Will check the rear side of the board first to check for obvious shorts and make photos.
Looking for a used oscilloscope in Germany and to improve my skills and knowledge...
Hello Applebox83,
if you are lucky the shifted plug only destroyed the 7400 at the strobeline.
Also in such case no key would be usable because the mainboard won´t recieve the
strobe signal to pick off the data from the datalines. In such case you might be
lucky that the encoder has not been destroyed.
It´s therefor recommended to first replace the 7400 and test the keyboard if it
"gets back to life".
It´s a rule that shortcuts that cause a damage allways seek shortest path and weakest line.
So maybe the shortcut in the 7400 kept the damage away from the encoderchip.
speedyG