Re: Can I use a US motherboard in my European Apple IIe?

["Bryan Parkoff" <nospam@nospam.com>]

"Knut Roll-Lund" <kr-lund@nogarbage.online.no> wrote in message 
qd6dnbF6C-gaJbHe4p2dnA@telenor.com">news:qd6dnbF6C-gaJbHe4p2dnA@telenor.com...
> Bryan Parkoff wrote:
>
>> "Knut Roll-Lund" <kr-lund@nogarbage.online.no> wrote in message 
>> 0tadnVSuSKH3HrHeRVnzvA@telenor.com">news:0tadnVSuSKH3HrHeRVnzvA@telenor.com...
>>
>>>Well, I'm asking this because it might be a solution to my RGB problem.
>>>
>>>If I get a US IIe motherboard and put this in my European IIe I will get 
>>>60Hz video, is this the only difference apart from the aux port being in 
>>>a different place? Will the powerplug fit? Are the voltages supplied by 
>>>the European powersupply be the same? Anything I haven't though of? (yes, 
>>>yes, yes, no I think)
>>
>> Knut,
>>
>>     This is Bryan Parkoff.  I appreciate that you have shared technical 
>> difficulties with us.  I have already discussred with you via e-mail 
>> directly that it has to do with crystal osc chip to manipulate 50Hz and 
>> 60Hz.  Crystal OSC chip with 14.25MHz outputs 50Hz to sustain 312 lines 
>> for PAL monitors using 50Hz for European.  Another crystal OSC chip with 
>> 14.32MHz outputs 60Hz to sustain 262 lines for NTSC monitors in North 
>> America.  Two different OSC chips manipulate everything in the 
>> motherboard including aux slot, 7 slots, RAM, etc.
>>     You can use 50HZ or 60Hz in either North America or European that it 
>> works fine.  You can obtain US Apple //e motherboard (unenhanced or 
>> enhanced) with 14.32MHz Crystal OSC chip.  I am concerned that power 
>> supply does not sustain 240 volts because it does not have a switch.  I 
>> recommend that you obtain another power supply to replace US power supply 
>> which it has a switch of 120 volts and 240 volts.
>
> I meant to buy a motherboard not a full Apple, to change the crystal is 
> also a possibility but to get hold of the exact MHz may even be more 
> difficult than to get a motherboard of which there are several for sale at 
> eBay at the moment. My european motherboard is unenhanced so this might as 
> well be my enhancement upgrade.
>
>>     In my conclusion, US motherboard works fine in European using 240 
>> volts with no problems, but please note that it does not need to connect 
>> to PAL monitors.
>
> Yes, I would use my existing powersupply, case, keyboard, speaker. To send 
> a motherboard doesn't cost that much.
>
>>     Please let me know if you have succeeded resolving the problem with 
>> IBM 5153 monitor (rolling the screen) and US Apple //e motherboard.  If 
>> you wish to use NTSC monitor in European, do not forget that you need 240 
>> volts to 120 volts box otherwise 240 volts can destroy NTSC monitor by 
>> overloading voltages.
Knut,

    I explained earlier.  You can get or buy US motherboard.  It is cheaper 
than modifying motherboard by changing the crystal osc chip.  I prefer not 
to touch crystal osc chip otherwise motherboard can be less reliable or 
little damage by making mistake to de-solder and re-solder.  Both US and 
European motherboards have same design, but US uses 14.32MHz crystal OSC 
chip to support NTSC while European uses 14.25MHz crystal OSC chip to 
support PAL.
    Someone as hacker attempts to change from 14.32MHz crystal osc chip to 
higher frequency like 30MHz or more.  It does not cause the damage to the 
motherboard, but it will fail to respond because floppy disk needs to 
sustain 1MHz and NTSC/PAL needs to sustain 14MHz.
    It is wise to buy US motherboard somewhere like eBay.

> The European CGA monitor I have works with the image from a CGA card 
> without rolling. This signal is 60Hz so if I can make my Apple output a 
> 60Hz signal either by replacing the motherboard or by changing the crystal 
> I can't see why it shouldn't work.
>
> Bryan, I wanted to ask the group because there might also be Europeans and 
> other people with experience in just this. I would also be interested in 
> your experience. You wondered about getting a CGA monitor and try it with 
> your NTSC Apple did you do so? I though it would take some time if you 
> did. I'm so sure the monitor will work that I think it would not be 
> necessary to wait for your success unless there would be a problem fitting 
> the motherboard in as was my question here.

    It is always good idea to post to the newsgroups so someone can see 
Knut's and Bryan's posts for progressing to fix CGA monitor with Apple //e 
RGB card.  I am concerned that nobody is interested, but it is only a hope 
to see the results.

Bryan Parkoff