Quote:
Originally Posted by ajk
I've got some photos in an old thread of mine where you can see all the RTC related stuff completely untouched. |
Very tidy.
I have an A500 with accelerator and two stock(?) ones. The warranty seal having been broken on both is the whole background for my questions. I just want a good grip again on exactly what was manufactured and sold.
That way, I can first make sure it's stock and then figure out what I can change.
(re: 8372)
Quote:
Originally Posted by Jope
The easy choices there are 1MB chip or 512/512. They didn't configure them for 1MB chip from the factory, probably due to compatibility reasons.
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It feels like the
size of each type of RAM shouldn't cause a hardware incompatibility. Strange. Maybe slowmem was hacked in to allow it at all, and now a different solution is required to do it properly. It shouldn't require more ICs, since it handles both types. Either way it was good to support internal fastmem even in the form of slowmem, it enables quite a few things OS-wise.
(re: 8371)
Quote:
Originally Posted by Jope
It is fully compatible. You will be limited to 512k of chip after that.
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ACA500Plus requires 8372 to get 1MB chip, and I want this for my almost-stock work machine. But I might set up an A500 for circa 1988 demos maybe even with kick 1.2, and then use 8371 to run demos with "incorrect" Copper lists and Blitter inits.
Quote:
Originally Posted by Jope
As ajk said, if the rev8 board was in a computer with an A-500 badge, no RTC was populated and there is only 512k of RAM. If the board was on an A-500 plus case, the RTC + battery were installed and a full 1MB is on the board.
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Yup, so all Rev 8 are A500 not A500+, and no A500 came with RTC. Very interesting with the A500+ legend on the pure-A500 mobo
Quote:
Originally Posted by Jope
For the downgraded rev8 A-500, one TTL chip is also missing and some jumpers are in a different order for it to be a 512 mobo/512 trapdoor setup. The jumpers can be adjusted, the missing RAM chips and the TTL chip added for it to become an A500+ with 1MB on the mobo and 1MB possible in the trapdoor. Instructions are pretty easy to find here on support.hardware.
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So again, Rev8 mobos even though they say A500+ are still pure A500 boards and you have to mod it to get A500+ behavior.
Hmm, one more curious question
Quote:
Originally Posted by Jope
Rev 6: OCS Denise, 1MB Agnus, CSG Gary, Kick 1.3, power LED goes dim
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Since I have this and get 1MB Chip, how is ECS Denise not required? It already can read from addresses in the 512k-1MB chip range, or all addressing is done by Agnus so that no other ECS chips are required (e.g. Paula)?