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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Cyberus on August 11, 2003, 09:14:37 AM
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I was just wondering what actually limits the RAM in an A500. I recently picked up a Midget Racer accelerator for my trusty old (almost 14 years!) A500, and it has an 8MB add on card, but what's to stop me populating my GVP Impact II card with even more RAM? I see everywhere that it can have a maximum of 9MB, but why? Is it just that this is all that was envisaged as being possible at the time?
Cheers
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On my towerized+zorroed A500 with Blizzard 2060:
128 MB on Blizzard, max 8 MB on Oktagon 2008 and 2 MB on Megachip2, so total max of 138 MB.
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@ zipper
Thats one loaded a500 !
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So the zorroII area takes just max 8 MB. You need an accelerator that uses 32bit area for addressing memory.
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Whoa, overkill!
But why not buy an A2000, or is it because
a) like me you have a bit of an A500 fetish?
b) A500 mobos are ten a penny?
Cheers
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a)
and a shopkeeper who sold me the tower instead of just a Slingshot - and then I just decided to get the best. I was very sorry that Blizzard 2604 PPC board never got to the shelves. :-? :-? :-?
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@Cyberus
The RAM in an A500 is limited by the fact that the 68000 can only address a maximum of 16 Meg RAM. Once you take away bits that are reserved and used for hardware etc, you are left with 8Meg FAST RAM, 1 MEG CHIP RAM (although 2 megs can be addressed, the custom chips in A500 can only address that much max), and 512k (or 1 meg, can't remember) of RANGER RAM, which is known as the slow RAM. If you add a board with a full 68020 or better, you will be able to have more RAM because they use 32 bit addresses.
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So with an 030 accelerator, I should in theory be able to add more than 8MB....
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So with an 030 accelerator, I should in theory be able to add more than 8MB....
Correct. Most boards should allow at least 64mb
(although the 32 bit '030 can in theory address
far more).
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Almost all 030 accelerators map their memory outside ZII area, so 99% yes.
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Unfortunately, the GVP A530 only allows 8MB, through a proprietary SIMM layout :-(
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Bummer, there's always a catch...
I guess you just need to check each product to be sure before you buy.
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I'm hoping to combine the RAM on the accelerator - 8MB, with the RAM from the machine and KCS Powerboard - 1MB, with another 4MB I have in GVP 50-pin SIMMS in my 'sidecar' SCSI controller, giving a total of 12 MB...
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zipper wrote:
On my towerized+zorroed A500 with Blizzard 2060:
128 MB on Blizzard, max 8 MB on Oktagon 2008 and 2 MB on Megachip2, so total max of 138 MB.
:-o WOW! :-o
That I would call a Atari520ST killer. :-P
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zipper wrote:
On my towerized+zorroed A500 with Blizzard 2060:
128 MB on Blizzard, max 8 MB on Oktagon 2008 and 2 MB on Megachip2, so total max of 138 MB.
That must be an infintive (sp?) busboard?
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I have an a500 with 4 meg memory expansion in slot underneath a500 and i have a roctec hard drive which i have fitted a full 8 meg memory to but i have not tried booting it yet i will later to see if it will work with 12 meg of memory . :-o :-)
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Infinitiv was a trademark (?) by Micronik; the tower/busboard compo was really made by Micronik. Just looks like the first Ramiga Z5 for A1200. I think they began with towers for A2000 and A500, mine has been done ca. 1993; I bought it 1996. The kbd box has an Infinitiv logo on it.
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Heh, to think that the original spec of the A500 (in the A500 manual) said 10MB RAM maximum :-)
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On my towerized+zorroed A500 with Blizzard 2060...
Hang on, doesn't the 2060 fit in the CPU fast slot, which the A500 doesn't have?
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The A500 side expansion slot is identical to the A2000 fast slot, except it's the opposite gender. The expansion boards that come with a500 towers (
(and other expansions like the bodega bay) usually included an A2000 style fast slot in addition to a couple zorro2 slots.
Imagine if the Blizzard 2604 had been released... You could stick one of those on a A1000 :-)
-Paul
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Hmmm... I'm not so sure the 8 meg limit is correct
in a stock A500. I have an A1000, which (I think) is
basically the same machine as an A500.
The A1k has the 512k Agnus chip. My A1k has an
512k expansion ram for a total of 1 meg stock.
I have a RocTec A500 harddrive with 8 megs ram
installed. I use the drive on the A1k and when it boots
it shows 512k chip and 8 1/2 megs fast.
So unless there is something different between
the two machines, then 8 megs is not the limit.
I don't know what would be the limit, but my A1k
seems to tell me its not 8 megs.
I had always thought it was 16 megs but I could
very easily be wrong about that.
Mel Ott
:-o :-D
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10meg on a standard 68000 _if_ you use a megachip adapter
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@ Mel Ott:
That sounds spot on
512k CHIP
512k SLOW
8 Meg FAST
Fairly standard. Worbench and avail report both SLOW and FAST RAM as 'FAST' RAM.
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:-o The most I've ever attached to my A500+ is an Action Replay MK 3, a Sampling Cartridge and a MIDI device. :-o
Any exrtra ram always came with the various A500's that I owned.
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PaSha wrote:
The A500 side expansion slot is identical to the A2000 fast slot, except it's the opposite gender.
Hmm, the CPU fast slot is a 100 pin slot, pin compatible with Zorro II, but the CPU slot has a 28MHz (?) CLK (?) line doesn't it?
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Cyberus wrote:
PaSha wrote:
The A500 side expansion slot is identical to the A2000 fast slot, except it's the opposite gender.
Hmm, the CPU fast slot is a 100 pin slot, pin compatible with Zorro II, but the CPU slot has a 28MHz (?) CLK (?) line doesn't it?
Just simulate it with a clock multiplyer off the 7Mhz line
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@aardvark
Close but no cigar .....
2MB chip (with ECS-Agnus)
8MB fast
1.8MB "ranger" (needs adapter to Gary)
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If you get a Zorro 2 expander, you will get 128 Mb in any blizzard for A2000, and thats only in the CPU CARD....
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I have 128 megs in my Amiga 500 Tower of Power! :-D
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I've got an A500+ in a Micronik Tower and I've been toying with an idea... The memory card from an Amiga 2000A has 512kB Ranger/slowmem and I have some extra chips to populate it fully to 1MB. I'll then put it into the CPU slot of the tower; then I wouldn't have to mess with the Gary. I found one off ebay for 1 euro, but unfortunately it didn't work (I tested it in my A2000 as well, to make sure). If I find another one I'll have:
2MB chipmem
8MB fastmem
1MB slowmem
512kB shadow RAM on my Blizzard Turbo board
That'd be one maxed out 68000 A500+! :-D It'd be cool to find one of those Supra 28MHz 68000 accelerators, since the Blizzard Turbo board only runs at 14MHz, but then I'd lose the 512kB shadow RAM... :-?
/Martin
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@DoomMaster
Is that Military Grade memory?
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The Maximun RAM on A500 (68000/010 cpu) is 8mb of FAST MEMORY & 2mb of chip ram if you have installed the fat agnus, its possible add "slow ram" but with this configurarion you can have problems and your amiga is very possible the lost of speed, the best performance is 8mb fast ram+2mb chip (i have this memory on my CDTV with 010 cpu)
PS: if you use an A500 accelerator is possible add more memory of course the derringer 030 up to 32mb, see www.amiga-hardware.com
cheers
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What is the maximum chip ram that kick/wb 1.3 can accept?
I have just fitted a DKB megAchip expansion into my cdtv it definately has the correct agnus but I can only see one meg.
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Kronos wrote:
@aardvark
Close but no cigar .....
2MB chip (with ECS-Agnus)
8MB fast
1.8MB "ranger" (needs adapter to Gary)
Exactly...