A600 8Mb fast expansion

[rkauer]

 But then you need to change the Altera chip for a bigger one or even use some kind of "mini" CPU to control the memory chunks.

[da9000]

@rkaur:

I assume your response was for me? If so, I'm only asking so I can understand, not so much to have lordv do this. Version 1 is key, the rest is fantasy for now :-)

[rkauer]

da9000 wrote:
@rkaur:

I assume your response was for me? If so, I'm only asking so I can understand, not so much to have lordv do this. Version 1 is key, the rest is fantasy for now :-)

 Yes, it was. Add complexity to a simple, but elegant design is not good for a starting hardware. Like Minimig, baby steps, baby steps...

[da9000]

Indeed...  :roll:

[countzero]

I think piru was referring to C00000-D7FFFF which was intented for a500 internal expansion slot.

amiga system memory map

I wonder if it would be possible to hack card.resource to map this area instead of 200000-9FFFFF. of course 4mb pcmcia ram boards wouldn't work, but it should be possible to use CF card readers and ethernet devices, no ?

[Crumb]

@countzero

I wonder if it would be possible to hack card.resource to map this area instead of 200000-9FFFFF

that would be a good idea...



@thread

Do you remember 72c simm sockets are very hard to find now?... And desoldering a 72c socket is a huge job... IMHO it's easier to desolder the 4 chips of a simm than desoldering a 72c simm...

[Piru]

@countzero

I wonder if it would be possible to hack card.resource to map this area instead of 200000-9FFFFF.

Not with software only.

[1NOM155]

Crumb wrote:
@countzero

I wonder if it would be possible to hack card.resource to map this area instead of 200000-9FFFFF

that would be a good idea...



@thread

Do you remember 72c simm sockets are very hard to find now?... And desoldering a 72c socket is a huge job... IMHO it's easier to desolder the 4 chips of a simm than desoldering a 72c simm...

no way, in POR, you can find that in some stores.

[lordv]

Currently I'm fighting again with some long-term socket contact stability problems. DRAM chips seem to be OK since I've used nice "slow slew rate" option for altera outputs =)
 
The main problem besides socket contatability, from my point of view, is indeed pcmcia 4 Mb space. So now my plans are to redesign board. It will probably have epm3064 in tqfp100 with no extra MUXes and some jumpers to select none/4/8 Mb size. SIMM sockets are indeed very hard to find except for desoldeting them from old PCs (and more, they should be laying and not standing as in majority of PCs). I don't think this way is acceptable.

[1NOM155]

lordv wrote:
Currently I'm fighting again with some long-term socket contact stability problems. DRAM chips seem to be OK since I've used nice "slow slew rate" option for altera outputs =)
 
The main problem besides socket contatability, from my point of view, is indeed pcmcia 4 Mb space. So now my plans are to redesign board. It will probably have epm3064 in tqfp100 with no extra MUXes and some jumpers to select none/4/8 Mb size. SIMM sockets are indeed very hard to find except for desoldeting them from old PCs (and more, they should be laying and not standing as in majority of PCs). I don't think this way is acceptable.

what about of U2J1/U3J1 sockets??

[rkauer]

lordv wrote:
--zip--
SIMM sockets are indeed very hard to find except for desoldering them from old PCs (and more, they should be laying and not standing as in majority of PCs). I don't think this way is acceptable.

 So why bother with connectors? Simply leave the copper traces to the final user solder a SIMM right in the place! SIMM banks are common as mud, but the socket isn't.

 With this you have a low profile board.

 For the contact issue in the processor side, exists a simple fix: put two plastic stands on the far side (ports side) and a screw in the frontmost side. Jens did this in the aka630 accelerator. Much better than put some kind of glue to keep the board in place.

[rkauer]

 Just up the thread!

[lordv]

Currently I'm planning sell some fully assembled old version PCBs (only 3 of them) to start making new ones. Unfortunately old PCBs will be sold to local people who sent me a lot of SIMMs to desolder. =) Anyway, the unpopulated PCBs of this design itself can still be ordered for smth 8$ each (I won't order a huge bunch of them, but little quantities will be priced like that).

Next version will have TQFP100 epm3064 CPLD, jumper for 0-4-8 Mb selection and some elegant (imho little piece of PCB under main PCB containing SMD 68pin PLCC socket, hope this will solve contactibility problems =)

Oh, as well, I should put some info concerning this old design... probably within few days =)

PS: Happy Christmas for those of you, who сelebrated it yesterday =)))

[1NOM155]

lordv wrote:
Currently I'm planning sell some fully assembled old version PCBs (only 3 of them) to start making new ones. Unfortunately old PCBs will be sold to local people who sent me a lot of SIMMs to desolder. =) Anyway, the unpopulated PCBs of this design itself can still be ordered for smth 8$ each (I won't order a huge bunch of them, but little quantities will be priced like that).

Next version will have TQFP100 epm3064 CPLD, jumper for 0-4-8 Mb selection and some elegant (imho little piece of PCB under main PCB containing SMD 68pin PLCC socket, hope this will solve contactibility problems =)

Oh, as well, I should put some info concerning this old design... probably within few days =)

PS: Happy Christmas for those of you, who сelebrated it yesterday =)))

why a jumper for 0 - memory? and can be possible to use SIMS or ram sockets?

[rkauer]

1NOM155 wrote:
why a jumper for 0 - memory? and can be possible to use SIMS or ram sockets?

 Jumper for zero: just for compatibility.

 2nd answer: not without a major redesign of the board itself. Maybe in version 1.3.

[alexh]

Why does anyone care about sockets and SIMMS etc. if the boards come fully populated with 8Mbytes soldered down and a jumper?