Amiga 500 Motherboard Revision 6 RAM upgrade ?

[restore2003]

Max payne 2 is the best game of this year oops thats a pc game.Stunt car racer is the best amiga game as well as the other 100 or so favourites i have.

Me and a bunch of classmates when we were 11/12 years old or so, we played stuntcar racer on two linked a500`s, had a competition, i got to the semi final, man that was fun  :-)

[Brian]

Well... you need to do 2 more things apart from the installing of the ram chips. You need to find JP2 close to the top of the ROM chip and cut the trace between the middle and the lower of the 3 pads and instead jumper the middle with the top pad. Next you need to find JP7a next to the internal mem/clock port and cut the trace between the middle and the lower of the 3 pads... that's it. If you prefer you can use a 2pol switch to change back to 512K ram in case a game refuse to work.

As someone else said you don't need to install the ramchips if you don't want to, instead you can just use a standard 501 mem upgrade card or alike and the same "hack" above will change the slowram of these cards into chipram (no the ram on these cards are NOT fastram contrary to what someone here said but chipram that's been given a different adress witch turns it into slowram. The hack will not slowdown you machine, just turn the extra mem into chipmem). :-D

[adolescent]

Ryu wrote:
hmm... excuse me if im wrong but doesnt 4x256=1024? which would mean it has 1mb of chip ram.... not 512k?... sorry for pointing out the obvious... :-)

No, 4x256 chips are 128kilobytes.  It's 4 x 256 kilobits / 8 = 128 kilobytes.  Using your math he would have 4M of RAM.   :-?

[Ryu]

well he never stated if it was Kb or KB......

[adolescent]

BTW, it's easier to solder additional 4x256k chips on top of the existing chips (ie. piggy back) than using the other solder pads.  I'm not sure however if other modifications are required.  (I used to have a CUAmiga mag that did a 2M upgrade like that but lost it some time ago).

[adolescent]

Ryu wrote:
well he never stated if it was Kb or KB......

He said 4x256k.  Knowing how RAM is labeled, the Amiga 500 architecture, and the industry at the time of production.  You should know that they wouldn't put 1M chips in it.  Also, I figure C= wouldn't waste 3.5M if they didn't have to.

[Lando]

Orjan wrote:
Actually... To be honest, isn´t Doom just a clone of Wolfenstein???  :-?

Yep.  and Wolfenstein is a clone of 3D Monster Maze on the ZX81.

[DoomMaster]

To Ryu:

hmm... excuse me if im wrong but doesnt 4x256=1024? which would mean it has 1mb of chip ram.... not 512k?... sorry for pointing out the obvious...

Yes, 4 X 256k does equal 1 meg, but 256k X 4 DRAMs do NOT.  That means 256K X 4 bits.  It takes 8 bits to make a byte.  So, this means that you have to have 256k X 8 to make 1 meg.  It takes 8 256k X 4 DRAMs to do that.  Sorry for pointing out the obvious- YOU ARE WRONG !!!!     :smack:

[Matt_H]

What you're trying to do doesn't sound like much of a salvage operation. C'mon, admit it! You want to have a nice, small, semi-luggable A500! :-)

3.1 should be usable in all A500s, although some revisions have a 1-31 pin swap with the ROM that I'm not quite clear about. A DKB MegAChip will give you 2Megs addressable Chip RAM. Get one of those, and pop a 512K card in the trapdoor, and you've got yourself a 2Meg A500. Plug a GVP 530 into the side expansion, and you've got yourself what is quite possibily one of the most respectable A500s on the planet. If you ask me, only the Viper 530 is a better accelerator card. Find one of those, an A570, put in a 1.3/3.1 kickswitch, and that'll solve your retro games crisis while still being a decent productivity machine.

[DoomMaster]

To Orjan:

Actually... To be honest, isn´t Doom just a clone of Wolfenstein???

No.  Wolfenstein was the first FPP game, but it was the success of Doom that actually started the FPP 3D gaming era.  Even today, Doom is still so popular, afterall Doom 3 is coming !!!!     :-D

[Damion]

(no the ram on these cards are NOT fastram contrary to what someone here said but chipram that's been given a different adress witch turns it into slowram. The hack will not slowdown you machine, just turn the extra mem into chipmem).

Bryan as I see it "slow" and 'fast' are relative terms..

 

[Methuselas]

Hey Doommaster,

Are you sure you wanna use thatA500?? I didn't know them to have military grade chips in them. It might fry your 'Professional A2000HD'

:roflmao: :roflmao: :roflmao: :roflmao:

[DoomMaster]

To Methuselas:     :destroy:

[jjans]

hey Matt_H, I can certainly vouch for the A530, as mine has run TOO great for me, and has kept me happy in the A500 stone age instead of getting an A2000, or higher. Only concern is smaller SCSI HD's that are harder to find now.

With absolutely no experience I have done the following with the A500 Rev 5 following docs found on aminet, and some cool advise from this site:

1.  Upgraded from 512 k to 1 MB chip mem Agnus;
2.  Upgraded 1 MB to 2 MB with DKB Megachip;
3.  Ripped off 128 k mem chips from a battery damaged A501 expansion card and soldered them onto an A590 to increase ram to 4 MB.

The A501 expansion card being the easiest way to up ram, Doom raises a good question. How much ram can an A500 rev 6 handle with an A501, DKB Megachip, and added chips to existing onboard ram?

I'd like to try it myself.

[Brian]

@ -D-: Fastram and Slowram are in fact two different things and that doesn't change wether you think so or not. :-P

About DOOM being the #1 of it's kind I don't know... I'm pritty sure there where a game called Eye of the beholder and simular games that was before DOOM's time. Sure DOOM is the first to allow to turn and walk incremental steps where the older games made the charracters jump 15feet at a time but still. That is just as valid a point as DOOM with it's none 3D being the spawnpoint of later 3D games, at least I think so. :-D

[Jagabot]

Actually, Dungeon Master for the Amiga, by FTL, is what all other 1st person shooter/adventures are based on. That includes DOOM. Dungeon Master invented the genre. Dune for the Amiga created the tactical strategy genre (Command & Conquor, Warcraft, etc.), SimCity started on the Amiga, so did Civilization and the entire "God" genre (Populous). Almost every good game genre was introduced because of the Amiga. PC's couldn't even play decent games until the early 90's for gosh sake.  :-D

I do recall a couple ram "hacks" for the 500, but mostly I remember that you had to modify a couple different pins (pin 41 on the Fatter Agnus 8372A and pin 32 on Gary) if you were doing them to non NTSC units. I also seem to recall that all internal RAM hacks just gave you more CHIP RAM (up to 1MB, I do not recall a 2MB hack but it might have been possible with a Fatter Agnus 8375), and I also recall that this hack also disabled any RAM expansion you intended to later add in the belly expansion bay, although the clock on a 501 would still function the additional 512k of fast ram wasn't seen. You could still add FAST RAM on the external Zorro slot using a SupraRAM or similar expansion device however.

My memory isn't the best when it comes to internal 500 hacks, but I do recall having soldered ram both onto the motherboard and "piggyback" onto the existing motherboard ram. But for some reason I seem to remember having 2MB CHIP RAM on a modified 2000/2500 but never on a 500. I could possibly be mistaken -- although because of the availability of the 8375 Fatter Agnus, [318069-17] was only for the 2000 with other 8375 versions only being available for the 3000 and 600, I doubt it was possible on the 500.