A500 Megaboard

[Zetr0]

Hello forum chummies

A little while back i picked up a Megaboard from a great guy on AmiBay, for my a500 resoration project.

Now theres very little info on this item, both on Amiga-Hardware and Amiga.Resource.

this is what i have found

MegaBoard by Zydec,
1992 Amiga A500 Interface: trapdoor slot, Gary socket

Features

• 1 MB RAM - gives 1.5 MB total
• eight 256k×4 DIPs soldered onto the board
• connects to the trapdoor slot
• an adapter board connects to the Gary socket
• expandable with a standard 512 kB trapdoor slot RAM expansion (not exceeding 9 cm in length) for 2 MB total
• disable switch
• requires Kickstart 1.3

heres some hardware pron of my board for some tasters

Front


Back



Now heres some questions, by adding this device (1.5MB ram) would this be added as Chip Ram or 1MB chip / 1MB Fast ?

I also have an Elbox A500 / CDTV 8MB upgrade which i got recently from eBay, I was wondering if this would conflict with the device in some way.

Front (thanks to BBOAH)


Back


anyway, any thoughts please postie

[coze]

wow, congrats zetro, good find !

I believe there should be jumper somewhere to configure 512k chip or 1mb chip. I had a similar board before, which had a jumper (it was called minimegs or something like that).

as for the conflict, probably the Elbox board takes whole zorro2 space. This adapter should take ranger memory space and chip ram probably. So they shouldn't conflict.

[TheCorfiot]

Hi Zetro,

That is indeed a nice expansion.

I think the board will give you 512KB extra chip Ram as long as you have configured the A500 MB accordingly & have the 8372 AGNUS.

Not sure about the other 1MB, it maybe fast or slow the traditional 512K "slow" ram is accessed by the CPU via the Custom chips, so in theory that is now taken up by the 1MB "chipmem".
I suggest plugging it in & use sysinfo to see where it is all being mapped.

Hopefully it may reside outside of the Zorro 2 8MB space.

Let us know

and of course nice piccies

[skote]

Ooer. There's one of these on eBay at the moment. Item # 310054158160

[Zetr0]

well my plans are simple,

the elbox 8mb ram will be used to test the A600 CPC i am having built by futurlec, they are also building 10 Narmi SVideo PCB's

I want to test the cpu handshaking to see if it works with the a600 using the cpc board i have (and others lol) designed, this will provide invaluable testing of the logic for the 020 accelerator project

[rkauer]

Originally Posted by Zetr0

well my plans are simple,

the elbox 8mb ram will be used to test the A600 CPC i am having built by futurlec, they are also building 10 Narmi SVideo PCB's

I want to test the cpu handshaking to see if it works with the a600 using the cpc board i have (and others lol) designed, this will provide invaluable testing of the logic for the 020 accelerator project

That - Megaboard - is - yummy!!!

Z, can I have it in that A500+ ????

Pretty, pretty, pretty, pretty please with sugar on top?

I'm afraid my package is going bigger and bigger... What is the price for renting a ship to grab the whole package from England to Brazil...

Hey! What about a container?

But my wife will kill me in the end...

[RedskullDC]

Hi Zetr0,

Originally Posted by Zetr0

Hello forum chummies
Features

• 1 MB RAM - gives 1.5 MB totalNow heres some questions, by adding this device (1.5MB ram) would this be added as Chip Ram or 1MB chip / 1MB Fast ?

....
I also have an Elbox A500 / CDTV 8MB upgrade which i got recently from eBay, I was wondering if this would conflict with the device in some way.

Think you will find that the extra 1MB appears at $C80000-$D7FFFF,
just above the normal A501 512k.

They also did a version which had memory right up to $DBFFFF I think, so as to avoid conflict with the RTC at $DC0000 up.

Would be easy to hack to operate all the extra 1.5MB as Chip if required.

GARY is easily fooled

Cheers,
Red