A600 8Mb fast expansion

[lordv]

I've just made such a beast! Look for photos here: http://www.amiga.org.ru/forum/viewtopic.php?p=12045
It autoconfigures!
Still some troubles with memory chips, i'm afraid some are slightly dead.

[lordv]

DJBase wrote:
PCMCIA Port will be dead then right?

Dunno
Currently only 4Mb are used (4th chip is very bad). It autoconfigures at $200000-$5FFFFF address range. 8Mb would autoconfigure at $200000-$9FFFFF.

Afaik pcmcia address range is somewhere in $Exxxxx or smth...

[lordv]

Trev wrote:
In my opinion, what truly makes the whole project work is the pin-up girl on the floppy drive. ;-)

 :roflmao:  :roflmao:  :roflmao:

[lordv]

The project will be open-source as soon as I finish testing board/swapping memory chips. I'll release schematics, PCB, source code for CPLD as well as programming file for it.
 
The PCB is mere 2-layer with 0.2mm clearances/copper trace widths.
The chip is Altera EPM7064S now, while EPM7032S or Atmel ATF1502 are planned for release (1502 is the same as 7032s, but you need to converse programming file from altera format to atmel format).
SMD-PLCC sockets have holes in its bottoms http://www.isa-elektronik.de/wgr/wg017/PLCC-SMD-drw1.png , so you can solder them easily with thin enough soldering iron. But for this board, to ensure good contact, you must break off socket bottom, bend its pins and solder it with some angle to plane (board). I'll make more photos soon =) Probably it's the most odd part of project

Dunno about kits. The problem mostly with DRAM chips, which could be only taken from 4 or 8Mb simms (2 or 4 chips/simm).

[lordv]

4- What's the name of the chick on the floppy drive ? (you should consider naming this project after her !)

Dunno
This is from previous owner =)

[lordv]

Sure you don't need /OE pin, you can place it to GND.
 
For 72pin simm, there is no exact schematics, but try looking here http://groups.google.com/group/fido7.ru.amiga/msg/c4b788490e24bfc4?dmode=source&output=gplain , unfortunately in russian only ;-) This is what I've used while soldering my extra chip MEG =)

If you already have one megabit chip soldered, consider soldering another over the top of it (not soldering /RAS pin).

PS: when joining together SIMM data bus (d0 to d16, d1 to d17 etc, needed only for 1 and 4Mb), beware of wrong SIMM routing, when not d0-d15 come from single chip but d0-d7,d16-d23 instead. The rule: both of bus signals being joined together must be from different chips.

[lordv]

Just curious... Do you know if adding a 020 would add too much complexity to your design? Anyway great job!

I'm afraid it would be totally new design...

[lordv]

skurk wrote:
Awesome!  I want one (provided that it doesn't disable my PCMCIA port)

Please say me somebody what address space is for PCMCIA on A600, then I'll give you clear answer.

[lordv]

0x600000 to 0x9FFFFF

So, there should be 2 versions - one autoconfiguring as 8mb with no pcmcia, other with only 4mb onboard =)

[lordv]

Currently no, because all pins of altera used up

But you can have two of them, replacing when needed =)

[lordv]

alexh wrote:
Could you add a config register?

What do you mean? Currently autoconfig only used in a tricky way only telling system we are, but ignoring high byte address system assigns to us. I can latch address given by system, but correct decoding of it will cause extra arithmetics/whatsoever so that design won't fit into epm7032. 7064 would probably help, but what for? It is expected we are the only autoconfiguring device in A600 =)

[lordv]

Dunno, if I can buy simm sockets here...

[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.

[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 =)))

[lordv]

I'm sorry for not coming here for a long period...

Here is the release: http://lvd.nedopc.com/Projects/a600_8mb/