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Amiga computer related discussion => Amiga Marketplace => Topic started by: Blizzard 128 MB on October 16, 2015, 09:39:20 AM
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Hello. I need 1×8372A Agnus chip and 5×44256 RAM chips.
I want to expand this motherboard onto 1 MB chipRAM:
http://amiga.resource.cx/photos/gallery/a500rev6a-2.jpg
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Hello. I need 1×8372A Agnus chip and 5×44256 RAM chips.
I want to expand this motherboard onto 1 MB chipRAM:
http://amiga.resource.cx/photos/gallery/a500rev6a-2.jpg
You are better off getting an a501, because then you'll have a battery backed up clock. Upgrading the ram on the motherboard isn't worth it.
But you do need an ECS agnus.
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8371 Agnus 0,5 MB chipRAM max., 8372A 1 MB. I have to change the 8371 Agnus chip to 8372A.
Tested 0,5 MB RAM expansion 20-30 €, unreal, isn't worth it. The completed, tested A500+PSU+mouse = 30-35 €.
Real prices: 6 chips max. 10 € + insured shipping 7 € = max. 17 €. So more expensive, than would be needed.
The original rev. 6. motherboard on real price + expansion components cost on real price = more expensive, than original rev. 8A 1 MB motherboard on real price. I have to work on the extension yet.
I want to expand to 1 MB the rev. 6 motherboard cheaply.
I do not want to buy a rev. 8A 1 MB motherboard. Shipping cost high.
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If you're going to do this then not only do you need 4 ram chips, but you also need 4 capacitors.
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I need a cheap 8372A chip. 10-15 € + shipping too expensive. I found 8 44256 RAM near.
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Yeah you are right about the 8372a. Whether you do the motherboard ram upgrade or the trapdoor upgrade, you will need the 8372a for one meg chip ram. Most 6a (but not all) motherboards came with a 8372a already on them. Commodore had already ran out of 8370 and 8371 s at that point.
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Which version PAL Agnus chips usable to the 1 MB chipRAM expansion?
http://www.bigbookofamigahardware.com/bboah/product.aspx?id=1478
2 MB 318069-18, 1 MB 318069-16, 2 MB 318069-10.
http://www.ebay.de/itm/Agnus-8375-1MB-fur-a500-2000-318069-16-/161859271010
Necessary any kind of modification on the rev. 6A motherboard?
I know this: http://s2.postimg.org/8o0x83w69/A500_6a_1_MBCHIP.png
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You want one of the 8372 variants. Probably 8372A. 8375 is only for very late model (Rev. 8) A500 boards (and A600, etc.), unless you're using a Megachip adapter or something like that. Look up the Wikipedia article on Agnus, there's a couple other good resources out there.
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Look: http://www.amibay.com/showthread.php?73225-Agnus-8375-chips-Agnus-%281MB%29-%28318069-16%29-new (http://www.amibay.com/showthread.php?73225-Agnus-8375-chips-Agnus-%281MB%29-%28318069-16%29-new)
http://www.bigbookofamigahardware.com/bboah/product.aspx?id=1478
Agnus (1MB) 8372 318069-02 A500 (PAL), A2000 (PAL) Regular Type
A500, not A500+:
Agnus (1MB) 8375 / 8375 R1 318069-16 A500 (PAL), A2000 (PAL)
A500 = rev. 6 motherboard. A500+ = rev. 8.
Rev. 6 motherboard + 8375 318069-16 OK. Or not?
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You want one of the 8372 variants. Probably 8372A. 8375 is only for very late model (Rev. 8) A500 boards (and A600, etc.), unless you're using a Megachip adapter or something like that. Look up the Wikipedia article on Agnus, there's a couple other good resources out there.
+1
on the 6a and 8a motherboards ntsc or pal is control by a jumper pad. Things get a liitle screwy on rev 5 and older.
I also suggest you read a chip ram upgrade and a motherboard ram upgrade guides before you do anything. These can be found on aminet.
The chip ram upgrade is really easy on a rev 6a, but you need to be more careful with the motherboard ram upgrade. You may want to take psxphill's suggestion and get an a501 or clone, just be careful about battery damage.
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https://en.wikipedia.org/wiki/MOS_Technology_Agnus
ECS Agnus which can address up to 1 MB of Chip RAM (https://en.wikipedia.org/wiki/Chip_RAM)
8375 (318069-16 only) (PAL) - Amiga 500 (https://en.wikipedia.org/wiki/Amiga_500) from Rev 6 (PAL); Amiga 2000 (https://en.wikipedia.org/wiki/Amiga_2000) model B from Rev 6.4 (PAL)
Rev. 6A 0,5 MB to 1 MB chipRAM:
Step 1. 4×44256 soldering (in socket).
Step 2. 8371 out, 8375 318069-16 in.
Step 3. 2 jumper modify:
http://s2.postimg.org/8o0x83w69/A500_6a_1_MBCHIP.png
Ready.
This OK? PAL system only.
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I don't understand your posts. What revision motherboard do you have currently and what Agnus is installed? You may already have one that supports 1MB.
Edit: look on the chart on Wikipedia or any of the other sources. Without looking myself I'm about 99% certain 8371 and 8375 are not pin-compatible. You can't just replace one with the other. You need an 8372A. (unless you want to rewire one of the sockets)
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Read all of the topic.
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Read all of the topic.
That's a snarky response to someone who's trying to help you. Learn English and come back when you can clearly word your questions. Bye! :griping:
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You cannot help. You do not have an idea of the asked things. I found about the internet what I wanted.