MiniMig with AGA

[freqmax]

Megadrive pads would go under, but CD32 pads have enough Commodore force in them to barely make it..
Looking here: http://www.softwolves.com/arkiv/cbm-hackers/1/1696.html
MegaDrive works the same as C= joysticks, however maybe with a different pinout. So it should work. And CD32 well.. it's Commodore stuff. So should work too.

Please read up on basic electronics before asking.

[psxphill]

Megadrive pads would go under, but CD32 pads have enough Commodore force in them to barely make it..
Looking here: http://www.softwolves.com/arkiv/cbm-hackers/1/1696.html
MegaDrive works the same as C= joysticks, however maybe with a different pinout. So it should work. And CD32 well.. it's Commodore stuff. So should work too.
 
Please read up on basic electronics before asking.

They all specify 5v, it was a 3.3v vs 5v question.

[freqmax]

Ohwell.. I took it as another pin mismatch so it won't work(tm).

Anyway  I found a page about connecting the Sega joypad to another console. He mentions "However, the newer Genesis controllers have a custom IC that adds the extra signals onto the same 9-wire cable. ". So the plain version should work out of the box. For the other one with an special IC one can use the following trick:

 (+5V input) --(Resistor 1-10k) -- (+3,3V output) -- (<3,3V Zenerdiode) -- (GND)

Then one just feed the +5V outputs of the joypad etc.. to this arrangement and connect the max 3,3V level to the FPGA. And ofcourse the joypad has to be feed with +5V supply.

[Louis Dias]

Ohwell.. I took it as another pin mismatch so it won't work(tm).

Anyway  I found a page about connecting the Sega joypad to another console. He mentions "However, the newer Genesis controllers have a custom IC that adds the extra signals onto the same 9-wire cable. ". So the plain version should work out of the box. For the other one with an special IC one can use the following trick:

 (+5V input) --(Resistor 1-10k) -- (+3,3V output) -- (<3,3V Zenerdiode) -- (GND)

Then one just feed the +5V outputs of the joypad etc.. to this arrangement and connect the max 3,3V level to the FPGA. And ofcourse the joypad has to be feed with +5V supply.

That must be for the 6-button pads(+mode button)...

[freqmax]

There were some hints that in order to accomplish AGA, 32-bit memory is a requirement as well as an externally 32-bit CPU. If yaqube:s AGA with 68000 is real then it's obvious that an ordinary 16-bit external CPU is enough. Or is there any situation when despite coded for 68000 a 32-bit interface for the CPU is an required?
And how about the memory?, 16-bit can provide the same amount of data, just need to double the MHz.. , or does the implementation use some 32-bit memory structure while keeping the CPU in 16-bit interface?

Regarding the CPU is there any benefits in implementing anything better than 68020 ..?, Because FPGA on-chip ram is quite scarce (~38 kB) so cache might be hard to implement. Maybe it's better to implement a plain 68020 and a steroid mode where certain functions are improved but still pretending to be 020 to software?, catch may be incompabilities.

[xyzzy]

Only sprite and bitplane DMA could use 32-bit fetches (64 with burst), everything else in AGA is still 16 bit, including the blitter and chip registers.

[freqmax]

With bitplane DMA I assume you mean the framebuffer memory ..?
Ie the transfer of the whole screen memory to the video DAC once per frame, x times per second.

[xyzzy]

Yes. Although I believe the display DMA fetches one chunk of data from each bitplane in turn, ie 16/32 or 64 bits of data before fetching the same amount for the next bitplane.

[logikstate]

OK, I may be dreaming here but...

I'm dreaming of an Amiga laptop powered by the FPGA arcade...

I know some Chinese companies make hooky Mac-A-Like laptop's etc...

Surely once the Replay board is complete this dream would not be a million miles away?

Am I just dreaming here? Is this something other people would like to see?



And, back to reality!

[freqmax]

If you find a matching LCD + keyboard + box it sure will work.
LCD is usually LVTTL or LVDS. Keyboard with small size might be worse, and a box fit for the purpose even worse.

[kolla]

Then there is battery, battery monitoring etc.

[mikej]

If you find a matching LCD + keyboard + box it sure will work.
LCD is usually LVTTL or LVDS. Keyboard with small size might be worse, and a box fit for the purpose even worse.

I've had the hi-res LCD/touch screen up and running with the board, there's a picture of it somewhere on the FPGAARCADE front page.

I'll stick up some pictures when I fire it up again. Looked nice!
/Mike

[freqmax]

@mikej, Is your on-pcb-flatscreen of LVDS type?

Regarding battery, it's not trivial.But doable. The thing about laptops is to get everything to fit inside a small box and get screen + keyboard + mousepad to align properly. Space is *tight*.
Having something spread out in modules to work on the labbench is way simpler.

[yaqube]

The thing about laptops is to get everything to fit inside a small box and get screen + keyboard + mousepad to align properly.

Sometimes I have an urge to gut a netbook and make a replacement mainboard with an FPGA

[freqmax]

yaqube, You'r not alone.. "fine laptop there".. *Evil grin* ;-)

[pyrre]

From the joysticks I've dismantled in my time autofire simply closed the joy button circuit... No special electronics at all.

Some auto-fires also had some sort of trigger circuit. (at least one joystick i had, had a trigger circuit..)