Custom Flashrom design for Amigas

[kipper2k]

Hi All,

I was talking to Zyga64 who mentioned he is using a 1mb flash rom for his Amiga so as usual i had to take a peek. So basically it uses a flash type rom that can be easily erased and reprogrammed without need of a UV light so for that reason alone i think its worth it. The speed of these roms are 70 - 90ns so fast enough with speed to spare.

I have to add a 4.7k resistor and mabbe a couple of jumpers for the 2 kickstarts version (upper and lower area of rom) but here's a preview of my initial design. You can buy these from a few places blank or otherwise. I would sell them programmed providing the buyer sent me the image to keep things legal.

here's a pic.

[DonAmiga]

Interesting

[Amiga1992]

I don't think you can flash the ROM from within the Amiga, can you? THAT would be really something, but I feel it could be impossible.

[hooverphonique]

actually, programming while the flashrom chip is in place should be possible by either using a piece of software that disables the os or running the os from ram and only redirecting reads to ram.. this of course depends on the flashrom chip used also (Microchip/SST makes chips that would support this, for instance).

ideally, some sort of locking mechanism should be put in place, so random writes to rom locations doesn't overwrite rom contents ;-)

[Amiga1992]

I'd be really interested in that.

Would it be possible to have it somehow 'piggybacked' or in line with the kickstart ROM on your Amiga by means of a PCB (like a ROM switcher) and be flashed when it isn't active, while a switch kivks it in when you want to use it? Sounds a bit improbable but the hardware gods should tell me best.

I am just wondering about how softkick works. If you could do something similar it would rock.

[mfilos]

Writing ROMS to Flash media was made in the past but stopped due to legale issues.
You can see a full thread by Reptile on a1k.org here: http://www.a1k.org/forum/showthread.php?t=13078

I've been telling that for a long time so seeing this thread just feeds me with hope

I have found a similar (if not the same) product that already exists in the Polish market and you can check it out here:
http://www.eliptor.pl/p86,pamiec-fla...-a-27c800.html
(you can see a use on an A600 here)

These are equivalent 26C800 ROMS (1MB).
We just need a special tool like Reptile's FlashRunner or even a future version of Remus (current version has the button but it's not working) to be able to flash whatever kick we want via software!!!

[Toni Wilen]

IMHO it needs to be in-circuit programmable. Removal and replacement is painful and will kill the socket sooner or later (without replacing it with ZIF socket), exactly same with EPROMs, only gain is quicker erase time..

I have that Polish Flash to DIP adapter and it isn't that useful as it looks because of above reasons.

Of course some extra logic is needed because Gary/Gayle blocks any write attempts to ROM regions.

Here is my wanted feature list: http://eab.abime.net/showpost.php?p=689709&postcount=33

I'll take 4+ if it has most features listed above

[mfilos]

I agree with that Toni. That's why we need to make a program like Reptile's FlashRunner to be able to write such ROMS from the Amiga side without the need to pull it out for programming it on the PC.

[Ratte]

FlashRunner is written by Alexco/a1k.org.
Btw. you can find basic flashrom details in a1200 shematics.
Gary needs to be toggled for A4000 for Rom-Enable (A4000T shematics - P152)

[Toni Wilen]

Software is not a problem, flash writing is very easy.

ROM socket on top of the adapter would be perfect failsafe solution, if flash rom is empty or flashing failed, just switch to on-board ROM, boot, run flasher, switch back to flash, write the flash rom and try again.

[pandy71]

Originally Posted by Toni Wilen

Of course some extra logic is needed because Gary/Gayle blocks any write attempts to ROM regions.

Hmmm - on A600 schematics there is FLASH use description... (page 5-10)

Originally Posted by Toni Wilen

Here is my wanted feature list: http://eab.abime.net/showpost.php?p=689709&postcount=33

I'll take 4+ if it has most features listed above

Perhaps in some not so far future?

[Toni Wilen]

A500 does not have any flash support stuff. It isn't that easy.

[Amiga1992]

Originally Posted by Toni Wilen

Here is my wanted feature list: http://eab.abime.net/showpost.php?p=689709&postcount=33

I think that's exactly what I was trying to describe! I don't want to be taking the ROM out of the computer, I want to install it once and use it. Would be an incredibly useful solution specially for us who like to make custom ROMs.
(would also be nice to have a tool to make custom kickstarts that works for every kickstart ROM version)

[kipper2k]

Is Flashrunner available for public use? The WE pin of the flash can be controlled by a jumper to prevent accidental (or malicious) writes. The risk of failed flashes to the chip would be minimal providing the Amiga itself is stable. Obviously for those people that cannot flash the chip outside the Amiga, flashing the chip would be a scary process, but one we do quite a lot with routers, PC's etc.

If a software flashing utility is available then i believe flash recovery could be obtained by mounting an old KS on top of the flashrom, booting the Amiga, flipping a switch or jumper and reflashing the flashrom. I think one of the common reasons of the flash failing would be peoples images that are incorrect, byteswapped when not required and vica versa so recovery would be very useful.

Of course it is also possible to have 2 flash roms on a board that allows multiple flash roms (they are cheap (about $3 -$4 dependent on quantity)). The second rom could also act as a backup to allow recovery of the other flash. I would be willing to try to make this according to peoples requirements if possible. Any help with extra circuitry i could implement would be welcome

edit: price on a one chip version would be less than $10 so i think the pricing is attractive

[Amiga1992]

I'm more and more interested in this!

[Toni Wilen]

In my opinion 2xflash is technically better but it also requires correct programmer (basic eprommer won't work). 1xflash + rom socket is probably much more user friendly. Of course 2xflash + socket would be even better

But does extra socket + installed rom still fit on all Amiga models?

Unfortunately it still needs some extra logic (single GAL + extra wire or similar I guess should be enough) to handle write support. At least A500/A2000 needs it.

I think I still have my ugly m68k flash programming code somewhere that I used to test polish adapter mentioned above. If there are no sources available for other (and more clean..) versions..

[kipper2k]

Originally Posted by Toni Wilen

In my opinion 2xflash is technically better but it also requires correct programmer (basic eprommer won't work). 1xflash + rom socket is probably much more user friendly. Of course 2xflash + socket would be even better

But does extra socket + installed rom still fit on all Amiga models?

Unfortunately it still needs some extra logic (single GAL + extra wire or similar I guess should be enough) to handle write support. At least A500/A2000 needs it.

I think I still have my ugly m68k flash programming code somewhere that I used to test polish adapter mentioned above. If there are no sources available for other (and more clean..) versions..

Thanks Toni,

here is the datasheets i referenced for pinouts, The 29f800 i used was based on the macronix. I think all the 29f800 series by all manufacturers are idendical pinouts (at least i would hope so.

http://www.digikey.ca/product-detail...021-ND/2744704

here is the pinout for the presently used DIP 27c800.

http://dforce3000.de/pub/datasheets/27c800.pdf

[kipper2k]

I just received a link from my Polish friend that he found on Aminet...

A500 FlashROM based kickstart switcher/programmer project V1.0 (25.05.03)Allows you to select from (in addition to your existing kickstart chip)either 2 x 512k or 1x 1MB kickstart images.Kickstart images can be programmed to the board in-system at any time.The board can also be used to program the BIOS chips in your brand new Amiga One.Enjoy,Redskull DC

http://aminet.net/package/docs/hard/DC-KF500

Would this be a good starting point for software/hardware implementatin

[mfilos]

Haha kipper2k my friend, I sent that link some time ago to Phipscube when we talk about making such a project as he's very good at some homebrew stuff.

This is a really nice starting point but if we had FlashRunner it would be really neat as well.
All the job tbh, have been done and worked, it's just that it was made a long time ago and due to legal stuff it stopped from hitting public.

A collaboration between a1k.org members about this subject would be really awesome just not to re-invent the wheel

[Toni Wilen]

I don't care how it is done, I only care about features