A600 8Mb fast expansion

[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/

[lordv]

Well, if any of you REALLY wanna order unpopulated PCB plus a programmed CPLD, PLEASE write to my email so that I can manage orders easier. Email could be found in the README.txt inside the archive.

[lordv]

The first run of 6 PCBs for old design is ordered, will arrive soon. Also 4 of new (2008 y) boards ordered, I'll assemble one as soon as they arrive.

[lordv]

Update on http://lvd.nedopc.com/Projects/a600_8mb/index.html

Now there are 4Mb PCMCIA-friendly firmware as well as 8Mb NON-autoconfiguring one. See READMEs for more information.

[lordv]

The things are simpler than they seem to be

Inside the CPLD there are two independent logic schemes: first controls DRAM (/RAS /CAS, refresh, chip selecting, address multiplexing, etc.), second does autoconfig.

So the amount of memory which physically present is determined by the first part, while the amount found by OS - determined by the second one.

4 and 8Mb differ in first part (for 4Mb, two memory chips are idling all the time) and also by second (4Mb size reported instead of 8Mb).

8Mb non-autoconf in comparison to 8Mb autoconf version, obviously lacks autoconf features =)


New revision will have jumpers to allow you to select 4mb or 8mb, or switch fastmem completely. Also I'm planning trying so-called "slow" memory space (4mb+slow, only slow).
Another improvement is no need to tilt overCPU socket (instead, the board itself is two-level).

[lordv]

Colani1200:

Could you explain that a little further? How will the new version be connected?

The same way, but the board will be two level, so that no need to tilt the socket when soldering it, also better cooling of CPU and chipset beneath the board. It looks like this: http://dlcorp.ucoz.ru/_fr/1/3207130.jpg http://dlcorp.ucoz.ru/_fr/1/3208886.jpg


Regarding A500, it probably should work, but I haven't A500 to check. Probably new version would be easier to adapt for A500.

[lordv]

1NOM155 wrote:

the new PCB, its great, because "on future" can be use on every Amigas with 68K CPU, just have to change CPU connector.

Well, not on every 68k, but definitely on every 68000 =)
68020 has completely different bus. To make things worse, A1200 /DSACKs every empty memory space hole, so one have to either overtake /DSACK signals on the A1200 trapdoor (thus making short-circuiting for motherboard DSACK drivers) or work without any wait states. It is almost impossible for 14MHz 2cycle accesses with ordinary 70ns DRAMs.

[lordv]

rkauer wrote:
 Do I need to relocate the hd of the A600 with this new design, like the old one?

I've seen the 2.5" IDE support only on some not-very-good photos. But it is situated just over the CPU, no place for anything over it. So I think yes, you have to relocate. I can recommend you using CF-IDE adapter which works just fine, cool and noiseless, and could be stored anywhere inside or outside A600

[lordv]

New (2008 year) board is ready!

Features:

 - PCMCIA-friendly

 - Better CPU and chipset ICs cooling than in old (2007) board

 - highly configurable by only two jumpers:
   * no fast memory
   * 8 Mb autoconfiguring fastram, no PCMCIA
   * 4 Mb autoconfiguring fastram, PCMCIA available
   * 1.5 Mb "slow" ram (but actually no wait states) at $C00000-$D7FFFF (automatically detected by kickstart)
   * 1.5 Mb "slow" + 4 Mb autoconfiguring fastram, in total 5.5 Mb with PCMCIA

 - Could be used with A500 as well (requires soldering skills), and with virtually any 68000-based device (requires CPLD firmware modification).


Some photos:









Orders could be placed at http://amigasc.nm.ru

[lordv]

@rkauer:
if you'd like to switch between all modes without opening case, you have to solder three wires. There are 4 pins in square, two pins are ground, another two are connected to CPLD. POssible configurations are: no jumpers, one of two CPLD wires shorted to ground, both shorted to ground and CPLD wires shorted together but not to ground - five modes in total.

I'll write soon manual for this board with everything explained

Do you think there would be enough height clearance to use one of these??

Heh, I've used exactly the same thingy, it was located outside A600 with ribbon cable going from it. And then, eventually, it died. Since that I use this: http://www.espada-tech.ru/pr_-25410.shtml Of course, outside case (and without that metal bar).

[lordv]

Of course some insulation could be done. But with SMD PLCC socket the boards sits rather tight. You can fit some plastic stands in the holes on the upper part of board.

Regarding amigasc.nm.ru, there are still some problems, so if any, please contact acidrain directly at staspi yandex ru (insert @ and . appropriately).

I'm going to order some approx. 20 PCBs and parts and start soldering it.

[lordv]

rkauer, it is possible but then it is left untested: only programmed CPLD (not FPGA, hehe and nothing more.