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Author Topic: Questions about Chip RAM vs Fast RAM vs Slow RAM  (Read 6795 times)

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Offline MotoTopic starter

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Questions about Chip RAM vs Fast RAM vs Slow RAM
« on: October 06, 2009, 07:36:04 AM »
Hi Everybody,

I am just recently getting back into getting my Amiga 500 working again (while I wait for my new A1200 to come from AmigaKit!! Very excited!).  

So I cracked open the A500 case (since 1994) and I find that my system has:

stock 68k
a Spirit 2MB memory card
a 512kb Agnus chip (8370) and no 501 expansion card.

I remember using the extra RAM for a ram disk which I would then boot from it and do asm programming (k-seka!).

So last week I bought a 2mb Agnus chip like this one:
http://www.amiga-hardware.com/showhardware.cgi?HARDID=985

I had to remove my 2MB spirit board because it would not fit with the MiniMegiChip daughterboard in place.   I pulled the old 512k agnus and replaced it with the MegiMini board (and installed the Gary socket).

Low and behold it works and I now have 2MB of chip RAM but I lost ALL my FAST RAM in the process.   I am able to run PALBOOT which is awesome because I can see what all those amiga demos are supposed to look like without being cut off on the bottom and also everything sounds more sync'd up.  You have no idea how horrible it was getting all these cool PAL demos and having to run them in NTSC!

So here's my questions:

1) What is slow RAM?  Is it just another name for chip RAM?
2) Does this MiniMegi chip have a total of 2MB or 1.5MB of RAM on it, because the A500 comes with 512kb right off the bat but is this now lost memory?
3) Can I use a 1MB Agnus chip without having a 501 card in place and use PALBOOT?  
4) What's the best configuration I should use for this 500?
5) What happens if I get a 501 card now that I have 2mb chip already?  Does that become fast ram?  Is it ok to have 0 FAST RAM?
6) Is PALBOOT the only way to get my A500 into PAL mode?  I have to run it every time I reboot and then reboot again.

Sorry for all the questions.  I've been out of the game for a really long time (but still have all my original books/disks/hardware that I've been hauling around all these years!)

Thanks!

-daniel
500, 1200, 4000T
 

Offline MotoTopic starter

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Re: Questions about Chip RAM vs Fast RAM vs Slow RAM
« Reply #1 on: October 06, 2009, 02:50:37 PM »
Aaaaaah.  Thank you for that information.

Yes, my Amiga is indeed rev.5 board.  So basically the only good thing about the 501 board is that it has a battery backed up clock (which apparently leaks over time?)

I also have a 8372A agnus chip (1MB agnus) that I could use.
So which configuration is better?

A) 1MB agnus with only 512kb CHIP and 2MB Fast Ram (using 8372A and 2MB Spirit board which plugs into processor slot) == Total RAM 2.5 Meg

B) 2MB CHIP with NO fast Ram (using MegiMini only) == Total RAM 2 Meg

Having a 1MB agnus with only 512kb will still allow PAL Mode, so is the extra 1.5 CHIP memory utilized better than the extra 2mb FAST RAM is the question.  

This is my spirit board:
http://www.amiga-hardware.com/showhardware.cgi?HARDID=1072

Unfortunately it can't be put into place with the MegiMini chip in place but it would be awesome to have 2MB CHIP + 2MB Fast !  Oh well, dreaming.

Thanks again!

-daniel
500, 1200, 4000T