tezza
Veteran Member
Tez,
Can you determine the clock frequency of your IIe? (case markings?) What is the number printed on the IOU chip in your IIe? (344-00xx)
Dutch
I shall have a look tonight and post a reply.
Tez
Tez,
Can you determine the clock frequency of your IIe? (case markings?) What is the number printed on the IOU chip in your IIe? (344-00xx)
Dutch
I have a feeling vwestlife is right and these machines put out some wierd kind of hybrid NTSC signal but for 50Hz rather than 60hz? NTSC is written on the board rather than PAL. Certainly I've never got colour out of them except on the 240v Apple colour monitor.
Tez
Dutch,
Your query triggered some brain cells and I THINK has solved another puzzlling issue I had. See what you think.
Anyway, getting back to this thread, here are the details of my GOOD Apple IIe machine (now that I figure one of them has the wrong IOU IC in it..see under the link above).
This machine shows a nice colour image on my 240v Apple colour monitor, but only a monochrome image on the 110V machine:
The details are:
On the IOU - AMI 8623MBs 344-0022-A Apple 82 Philipines.
Written on the circuit board - Apple IIe International NTSC - Apple Computer 820-0188-C
Rev B-607-0288-C
I can't see anything that tells me the clock frequency. I can see only one Crystal on the board and that says :
-0002
5H
197
..does that mean anything to anyone?
I have a feeling vwestlife is right and these machines put out some wierd kind of hybrid NTSC signal but for 50Hz rather than 60hz? NTSC is written on the board rather than PAL. Certainly I've never got colour out of them except on the 240v Apple colour monitor.
Tez
It sounds like it might be a match to this crystal:
http://www.willegal.net/appleii/forsale/pal-crystal.jpg
which is 14.025 MHZ and intended for PAL systems. The color burst it generates is not close enough to NTSC standards for monitors to lock onto the color burst. If you substitute this vishay/dale crystal, it "may" work.
XT9UNLANA14M31818
regards,
Mike Willegal
I don't know if this has being mention yet, but the apple monitor having an NTSC system is touchy on the OSC Freq of the main board, if you are not getting color, start the computer and remove the lid, and with a plastic screwdriver, adjust the OSC cap, its a little variable cap on one of the corners, its being a long time since i've touched an apple PCB, so i can't exactly remember where it is, but its on the main board near one of the corners, just give it a little turn in both directions, you should get color.