SpritesMind.Net

[TmEE co.(TM)]

Here's the schematic:

And what it looks like:


Past few days I tried to get it working and I finally got it working (lots of software problems, and datasheet misunderstandings).
All EEPROM access is done by writing to and reading from address $A130F1.

I made this thing, so that people who want to get their game that uses batter back-up RAM into production, would use this instead, so that cartridge gets lot cheaper, as 2 logic chips and one EEPROM chip are lot more cheaper than battery and SRAM chip.

Here's the source required (TIMEPIN = $A130F1):

[8bitwizard]

It's a frickin' work of art. Point-to-point wiring taken to the extreme.

Even the prototype of my Atari 7800 cartridge wasn't that extreme. (I was a wimp and used 30ga wrap wire and hot-glued grid boards to the side of a regular board.)

[TmEE co.(TM)]

It is the only way for me, unless I get suitable drill, so I can make decent PCBs (one I had before, wasn't mine). I could let some company make my PCBs, but it is really expensive :/ and I have no schematic drawing software which the company could use to make the PCB.

How complicated is the I2C code of yours compared to my MicroWire code ?
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[Fonzie]

Héhé, again, impressive...
And is your code okay with overclocked system? Or the timing is really precise and any speedup/slowdown would break the read/write?


Here is my very old flash cart ^^... I used UV/sensitive board to make the PCB, it work very fine and don't require so heavy/big materials... You should buy a little UV kit (if you never tried doing that at home)
Just need paintshoppro for the pcb design (if you want to make it funny ^^) and a printer with transparent sheets

Of course, I still have heavy stupid wiring (even more stupid because i made the pcb LOL) but it helps a lot the logic & soldering ^^

[TmEE co.(TM)]

That mapper works even with OC, 10MHz tested and OK, must try higher clocks, but my MD2s VDP goes crazy after 10MHz

Your design is INSANE !!! I really like it !!!

I've never tried UV method, little expensive... and I can't get UV anywhere, maybe from sun, it is really hot in Estonia at the moment...

BTW, my flash cart programmer(and other stuff programmer aswell) uses less chips than yours
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[TmEE co.(TM)]

I lied a little, this doesn't work reliably on OCd MD
10MHz works, but its unstable.
11MHz seems to work perfectly
12MHz Instant crash, no TMSS screen... :/
13MHz as much as I could read the screen, seemed to work
14MHz VDP really crazy, couldn't tell if it works

I tried to make EEPROM controlling slower, but it didn't help at all.

93Cxx can handle 2MHz clock, and needs minimum of 500ns delays. But as much I've calculated, 10MHz OC gives you minimum of 1µs delays (which are bigger as instructions are memory related), which should be enough in any case...

Flashcart being written:

Flashcart being written, close up (SRAM cart in bottom corner):

In action on real thing:

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[TmEE co.(TM)]

I updated the schematic. I just needed to lower the value of the pull-up resistor, and everything started to work perfectly when overclocked !!!
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[evildragon]

wow! i could never do point to point wiring.. my old TV has that in it, and it scares the crap out of me..

[elan]

BTW UV lamps are in street lamps too.
Or as "moutain-sun lamp" for medical and health...

30-60euro...

But we have old one at home 30years old but still working...