Arcade game "1943 : the battle of midway" running on an FPGA!

[whiteb]

Would the Minimig (in Amiga mode) benefit from faster ram over the Ram used already ?  And pin to pin compatibility ? compatibility ?

How is it going to affect the game, with the 68000 Hardwired on the board ?

[whiteb]

jensl wrote:
Frederic, do you have a partnummber from Digikey for 10ns ram that will fit into the minimig ?

From what i have seen, there ARE compatible 10ns Ram, but I don't like the order quantities from Digikey (Like, 1000)

Not spending $18,000 just because I want two of the {bleep}s.
At that rate, I would buy two pieces at $77 each from Farnell.

[whiteb]

Illuwatar wrote:
The only difference between IS64WV51216 and IS62WV51216 used in MiniMig is the numbering order of the address lines. Power, data and control lines are all in the same place.

So, then does that mean they are not compatible ?, because the  Address lines are ordered differently ? (I would have thought that it DOES matter), The FPGA would be calling Addresses on the wrong pins, Meaning that the FPGA core would need to be recompiled with the appropriate Address lines on the correct FPGA pins for the board layout.

[whiteb]

jensl wrote:
This part should also work.
IS61WV51216BLL-10TLI and is orderable in 1 quantity for about 17$ from Digikey

Jens

But the pins are different.

Look at the minimig 1.1 Schematics, compared to the PDF from Digikey.

An example, Pin 23 (A13, RAM_A14 on minimig) is A10 on the chip, the point I am making is that the FPGA would need recompiling to match the NEW address lines for the chips.  They may be Pin for pin compatible for +V or GND, and Data, but the Address pins are different.

On minimig's FPGA, RAM_A14 is on pin 64 of the FPGA, for the new chips, Pin 23 is A10, which on the FPGA is RAM_A11 (Pin 61).

 

[whiteb]

Illuwatar wrote:
 If there were sockets for 44-TSOPII, then this would be a simple issue to test (or if someone have some professional resoldering station that removes SMD without damaging the PCB).

I have taken these chips off Damaged boards before, but that was with a standard 20W soldering wand, I would not wish to push my luck.  The board was damaged any way, and i was moving the chips to a fresh new board, several pads DID move but again, board = damaged any way = Me not care.

For the record, this was a Minimig board that someone else messed up the FPGA soldering, so slowly I am moving the components over to the new board, and I am probably going to do the Clothes Iron trick to get the FPGA off.

http://uk.youtube.com/watch?v=976AIzyTyv8

[edit] hey where do you get this bloody stuff from ?
http://uk.youtube.com/watch?v=FTQqjggeklo&feature=related

[whiteb]

FrenchShark wrote:

jensl wrote:
Haha, nice trick with the flat-iron.
I use every day the hot air from Leister.
http://www.klappenbach.de/html/hot_jet_s.html

I will order some 10ns sram from digikey.

I will report the results next week.

You won't notice any speed improvement with Minimig.
The DMA scheduler has to be rewritten for that.
That would be a nice project : 57 MHz bus speed, 4 times the AGA speed...

Regards,

Frederic

Well, add that to your list of tasks then

From what I am aware, AGA on Minimig is not going to happen,  due to space, and due to the lack of documentation on the hardware.  Additionally, the future production of NatAmi.

I do not feel confident about desoldering the 55ns ram from my Minimig, but making a new one at 10ns is not out of the question.

But to justify the cost, are we talking about more games than just 1943 being able to be run ?

But the one thing, the more complex the game, the more LE's needed, and at some point the Spartan 3 will fill up. is there a new board on the books with new FPGA ?

[whiteb]

Illuwatar wrote:
The largest Spartan 3 in QFP208 (that package used for MiniMig) is the 3E with 500k gates. Going bigger means BGA that is impossible to solder for most DIY freaks here...

If the BGA issue could be solved in some way, then there are not a big deal to create a larger MiniMig that could be code compatible (almost) with the original design - and in the same moment, add more RAM and a better video-DAC for 24bit graphics. The PCB itself needs to be at least 4-layer when using BGAs, but that is more a cost issue than a design problem.

The Minimig FPGA has 400k gates from memory, and yes, BGA is a {bleep}, its not a simple soldering Iron job (at any pitch), Reflow toaster ovens are needed.

I think I will stick with my current minimig the way it is