FlashROM replacing EEProms

[Zetr0]

Hello there my fellow forum chummies,

as some of you know I have been laid up these last coupld of weeks with some ass-nasty cold 'n flu.

Fortunately its shifting so I will finall be able to complete some bloody projects!!

now... alas brain keeps ticking over LOL

I would like to replace the standard EEProm (for kickstart) with FlashROM technology,



Initially I would like to just have a socketted pre-programmed FlashROM to replace a kickstart and then move onto implementing the FlashROM project for the A1200 that RedSKull made.

So what I would like to know is howmany bits do the A600 / A1200 use in regards to the 27C400 and the MX23C2100?

i.e. does the Amiga use only 8bits of the 16bits available or does it infact use the FULL 16bits to store?

My initiall conclusions lead me to believe that the miggy only uses them in BYTE mode (i.e. 8bit) but I would like to be 100% certain =)

this would conclude the A500-A2000 would use 8bit cel, where as the A1200 and A4000 would use two chips giveing then a a virtual Hi/Low 16bit cell

[DoogUK]

At a guess.....2x16 bit roms for a 32 bit computer

[Jope]

The Amiga runs the kickstart roms in 16 bit mode. Think how wide was the data bus in those Amigas again? :-)

Amount of 8-bit flashes needed: 2 for a500/600/2000, 4 for a1200/3000/4000

Not worth your while getting 16 bit flashes. They come in awkward packages.

Btw, flash IS an EEPROM. The kickstart chips are normally mask roms or EPROMs.

[Zetr0]

Originally Posted by DoogUK

At a guess.....2x16 bit roms for a 32 bit computer

Originally Posted by Jope

The Amiga runs the kickstart roms in 16 bit mode. Think how wide was the data bus in those Amigas again? :-)

Amount of 8-bit flashes needed: 2 for a500/600/2000, 4 for a1200/3000/4000

Not worth your while getting 16 bit flashes. They come in awkward packages.

Btw, flash IS an EEPROM. The kickstart chips are normally mask roms or EPROMs.

Cheers chaps, I had a nagging suspision =)

[Shadowfire]

Amiga Kickstarts are 16-bit (A500/600/2000) or 32-bit (A1200/A3000/A4000). The biggest problem will be finding 5V units, for instance, Digikey only has one type of 512Kx16 5V flash chip in stock, and it is $8.50-$9.15 per unit depending on quantity, and it's a 48-pin TSOP, which needs an adapter board.

[rkauer]

A 512k x 16bit is easy to find. The DIL-to-QFP adaptor is damn easy, too.

To put the original code inside it is not.

[Zetr0]

Originally Posted by Shadowfire

Amiga Kickstarts are 16-bit (A500/600/2000) or 32-bit (A1200/A3000/A4000). The biggest problem will be finding 5V units, for instance, Digikey only has one type of 512Kx16 5V flash chip in stock, and it is $8.50-$9.15 per unit depending on quantity, and it's a 48-pin TSOP, which needs an adapter board.

arguably I could use AT49F040, in serial?

ie. - in regards to an 500 say, I could use two chips with addresses sync'd between the two (U1 A7 would also be U2 A7) and the full 16bit path (from IO 0 to 15 configured as Q0 to Q15)

am I right in assuming I would need to split the ROM into two an odd byte file and an even byte file?

Originally Posted by rkauer

A 512k x 16bit is easy to find. The DIL-to-QFP adaptor is damn easy, too.

To put the original code inside it is not.

I have manny programers =)

[RedskullDC]

Hi Zetro,

Originally Posted by Zetr0

arguably I could use AT49F040, in serial?

ie. - in regards to an 500 say, I could use two chips with addresses sync'd between the two (U1 A7 would also be U2 A7) and the full 16bit path (from IO 0 to 15 configured as Q0 to Q15)

am I right in assuming I would need to split the ROM into two an odd byte file and an even byte file?

I have manny programers =)

Easiest to use a couple of 16-bit flash chips.
Very cheap on Ebay these days.
Check this guy for example:
http://myworld.ebay.com/tekdevice/
Search his items for 29F400.

PSOP/SOP are much easier to deal with than TSOP packages

--

You'll need 2x DIP adapters which you can find here:
http://www.ezprototypes.com/DipAdaptersMain.php

--

The kickflash project has the source code inside which includes the programming algorithm. May need slight tweaking for these chips, let me know if you need any help in that regard.

--

If you need to do any ROM splitting, use the program in the attached archive. Source is included. Quick hack by yours truly, does minimal error checking

Cheers,
Red

[Toni Wilen]

There is also ready-made flash adapters, for example: http://eliptor.pl/index.php?p215

I have been experimenting with those, only need few extra wires, resistors and switches and you have in-circuit programmable flash rom for Amiga, in my tests I have soldered them on top of original roms -> always boots, no need for separate programmers.

[rkauer]

Very interesting, Tony.

But if directly soldered, how then you can make different addresses and select the flash chips?

[Toni Wilen]

Originally Posted by rkauer

Very interesting, Tony.

But if directly soldered, how then you can make different addresses and select the flash chips?

It is easy to have separate chipselect line etc.. I did it this way because "remove chip, program it, put it back" after failed reprogramming will get annoying sooner or later.

[alexh]

Originally Posted by Toni Wilen

I did it this way because "remove chip, program it, put it back" after failed reprogramming will get annoying sooner or later.

Do the devices not support partial reprogramming so that after a failed reprogramming you only need to switch to a "good" bank?

[Magic]

What about this project?

http://www.a1k.org/forum/showthread.php?t=13078
http://www.terminal-entry.de/romflash.html

[Toni Wilen]

Originally Posted by alexh

Do the devices not support partial reprogramming so that after a failed reprogramming you only need to switch to a "good" bank?

Yeah but you can still mess up the erasing when experimenting

Originally Posted by Magic

What about this project?

http://www.a1k.org/forum/showthread.php?t=13078
http://www.terminal-entry.de/romflash.html

Looks best so far (if you can get it ready-made), unfortunately german-only means "does not exist" for most of us

Looks like the flash adapter is more or less the same + Gary/Gayle adapter connector for RW, chipselect etc lines.

Can you get the gary adapter separately? (I'd like to have some..) Does it support 1M ROM images? (I have plans that require this + lower 512K must be mapped to address zero when overlay is enabled) Where is A1200/A4000 version?

[Magic]

I don't know, they seem to be helpful people. I asked about buying the HD Floppy Fix in the USA and they sold be two new ones that work a treat! Now the project is available for download from the terminal entry page so you can make your own PCBs

Never hurts to ask. BTW check out the HD floppy Fix section while your over there.

[alexh]

Just for you non German readers out there :

http://www.terminal-entry.de/eng/romflash.html

If they did make them, perhaps for AmigaKit or Vesalia etc. I'd certainly buy 4 or so. (Depending on the price).

Originally Posted by Magic

BTW check out the HD floppy Fix section while your over there.

http://www.terminal-entry.de/eng/floppyfix.html

This is probably like the adapter that Ian Steadman made, but in a superior form factor (one that I suggested, but it is obvious). I wonder how well it works.

[Amiga-Digital]

Originally Posted by alexh

Just for you non German readers out there :

http://www.terminal-entry.de/eng/romflash.html

If they did make them, perhaps for AmigaKit or Vesalia etc. I'd certainly buy 4 or so. (Depending on the price).


http://www.terminal-entry.de/eng/floppyfix.html

This is probably like the adapter that Ian Steadman made, but in a superior form factor (one that I suggested, but it is obvious). I wonder how well it works.

the floppy adapter thats on terminal-entry that a hd adapter you can use a pc drive as 1.76 drive for the amiga ( works great )

[alexh]

Where did you get it from?? How much did it cost?

If these were available via Amigakit or some other major Amiga shop I'd buy 5 or so depending on the price. Come on AmigaKit, get in contact with them and arrange to get some manufactured

[Amiga-Digital]

Originally Posted by alexh

Where did you get it from?? How much did it cost?

If these were available via Amigakit or some other major Amiga shop I'd buy 5 or so depending on the price. Come on AmigaKit, get in contact with them and arrange to get some manufactured

you can build it at you one i have buy 1 for 2 years back on a1k.org for 25,- euro's but now the layout are for everyone you can donwload it and build soem of then

[Toni Wilen]

Originally Posted by Amiga-Digital

you can build it at you one i have buy 1 for 2 years back on a1k.org for 25,- euro's but now the layout are for everyone you can donwload it and build soem of then

"Problem" is that nobody wants to build anything anymore, it simply is not worth the trouble or time anymore (It was different in 1990s and earlier)

There is no lack of flash adapter schematics, there is lack of availability of ready-made flash adapters (exception being that polish adapter but it isn't 1:1 Amiga compatible either, at least if you want to have in-circuit flashing)