A600 Marpet Developments 604b

[lambrettadave]

Hi i noticed that this ram upgrade has 4 30 pin simms on it has anyone ever put higher value simms in it to see if more memory is gained

Dave

[fitzsteve]

Its a chip ram expansion not fast ram so only 2mb can be mapped therefore not really any point trying...

[lambrettadave]

Hmm I know this is chip ram but was just wondering thats all

[Zetr0]

@Lambrettadave

Hello there, Welcome to EAB =)

As steve'o points out the A600 trapdoor slot can only access 1MB of RAM, and as you know this is used as CHIP ram.

The Marpet board uses 4x 256KB 30pin simms to achieve a 1MB giving you the full 2MB of precious CHIP RAM.

There are a few other options for FAST ram and the A600 - one at the moment is PCMCIA SRAM - even 2MB is a god send and will speed up the A600 by about 30%

Hope that all helps

now since you have just joined up, take some time to have a look arround these fair boards - theres lots of retrolicious mischief to get upto =)

[alexh]

It's already been said but the answer is no. There are not the correct signals going to the trapdoor connector for anything other than an additional 1Mbyte of Chip RAM.

Plus I can confirm the Marpet 604b is the WORST A600 RAM card there is. It is too heavy when fitted with SIMMs and the mechanical strain on the edge connector can make it come loose all the time. I've had two in two different A600's and both have given yellow screens regularly when moved.

[lambrettadave]

ok Thanks steve, Zetro and alexh for the information,

Just one more thing for now. Would an 8mb Pcmcia flash card work as memory or would it show as writable drive or not work at all lol.

Dave

[fitzsteve]

Originally Posted by lambrettadave

ok Thanks steve, Zetro and alexh for the information,

Just one more thing for now. Would an 8mb Pcmcia flash card work as memory or would it show as writable drive or not work at all lol.

Dave

Hi Dave,

I think this card will show as 'Storage' but for Fast Ram you would need PCMCIA SRAM, 2mb is pretty useful 4mb better but *very* expensive

Steve.

[Zetr0]

@lambrettadave

Alas my friend, this question has been asked before a few times and the answer is - No, a flash card will only work as a harddrive.

Heres why

RAM (in the PCMCIA port) will have a persistent refresh and access of about 150 - 220ns
(thats about 185ns *nano seconds* pending card manufacture )

Flash RAM is a lot slower (around 6,000,000ns access), doesn't have a persistent refresh and operates within a Milisecond range (between 5-6ms) - there are 1 Million nanoseconds to a millisecond - and most Flash devices are about 6ms - thats over 32 thousand times (32,000) slower than Fast RAM

It is for this reason that Flash Ram cannot be used as FAST Ram.... but it will be a little quicker than native IDE speeds though =D

[lambrettadave]

All it was is that i had seen ata flash cards for sale on ebay.

But since Pcmcia cf card converters are so cheap as well as the cards them self it wouldnt be worth the bother of such a low hard disk size of 8mb,

hope that came out right

[lambrettadave]

Hi Zetr0 thanks for the detailed info on the flash drive.

Its good to know that there is some good folk on here who are in the know how

all the info is in my head now

cheers Dave