Custom Flashrom design for Amigas

[Toni Wilen]

Originally Posted by phipscube

Something i've been wondering too is if its possible to make 2MB Kicks. I think I read somewhere (A1k?) that there is enough space in address for up to 2.5MB?

Gayle based Amigas have 2M support built-in, extra 1M region at 0xa80000 - 0xb7ffff.

[phipscube]

Cool! So how easy/hard would it be to get a 2MB kick working?

Or should I just say, what has to be done?

I know on the A1200 custom kicks I made with mfilos' awesome guide there is a requirement for 1MB.ROM module. Is it just a case of somebody making a "2MB.ROM" file and using that instead with say a couple of 29f160's?

[mfilos]

I believe so Phipscube my friend. I don't know what the 1MB_ROM module does but I guess it enables the address space for the 1MB ROM to be inserted into.

I just wish Doobrey was more active here
He already done in the past a flash solution for A1200 (http://www.doobreynet.co.uk/flash.html) but some flashable ROMS like the ones we already said would have been ideal for usage in all Amigas.

FlashRunner or Doobrey's awesome Remus would have been awesome for just flashing the ROMS.

Btw, support for even 4MB ROMS has already been presented by SpeedGeek on his homebrew hack for A3000 and A4000 mobos (http://www.amibay.com/showthread.php?t=21720). We just need to combine the knowledge of software developers and hardware freakz to create such awesome stuff!

(I wish I could help more, but guides is the best thing I can do not having knowledge of how to programs on ASM or any Amiga language - sorry dos languages and vb is my cap)

[fryguy]

This is interesting sheisse I bought a kickflash card ages ago, i succeeded in flashing it but i was never able to use it. IIRC i got a guru after flashing a standard 3.1 ROM. So now it's just collecting dust.

[hooverphonique]

Originally Posted by RedskullDC

Hi Hooverphonique,


I guess you're referring to the MX29F1615.

True, it does require 10V on the *BYTE/VPP pin during programming.
Easily generated with a 2N2222/BC549 transistor and a resitor or two, as a function of *WE and the *CE signal to the flash chip.

Apart from that, it is pin for pin compatible with the 62408 mask ROM used in the Amigas.
(62408 is NC on pin 42 [A19]).

Cheers,
Red

Yes, that's what I was referring to ;-)

For drop-in replacement (i.e. an adapter with e.g. a wire-wrap rom socket) this would work in Amigas with 2M rom support.. The pinout of the 62408 does *not* work in e.g. A4000, and I guess it's the same for the 512K rom amigas..

[kipper2k]

I have made a few changes to the flashrom design.

I changed it to allow a 2mb AMD AM29F160D and also the regular 1mb AMD AM29f800B. I added some pads to what i think are the important signals that would need to be "toggled" depending upon usage.

So this is where i need help as my knowledge of addressing and other development issues is not that good. If i wanted to use it as a regular read only flash then no problem, however to make it flashable from within the Amiga itself i will need some help.

you can see from the pic i posted that i sent some signals to pads so that they could be modified by the end user to hopefully make this design into everything that people could hope for.

If everything looks ok i will go ahead and get some of thesee boards made. For those people with programmers that would like to help in this project then i would be willing to send them a 1mb and 2mb board (at my cost) to try to make this project a reality. If this design is missing something or wrong, let me know and i can make changes. I hope to get the boards (and chips) within the next 3 - 4 weeks If you want to help, send me a PM and we'll try to get the ball rolling.

Thanks

Here's the URL for the AMD 2mb 29f160d

http://www.spansion.com/Support/Data...29f160d_00.pdf

Here's a pic of the design.

[RedskullDC]

Hi mfilos, kipper2k, Hooverphonique et al.

Originally Posted by mfilos

I just wish Doobrey was more active here
He already done in the past a flash solution for A1200 (http://www.doobreynet.co.uk/flash.html) but some flashable ROMS like the ones we already said would have been ideal for usage in all Amigas.

We just need to combine the knowledge of software developers and hardware freakz to create such awesome stuff!

Sounds like a "gauntlet being thrown down" to me

I'll get to work on a 2MB Kickstart design to suit the A1200!

Will do one for the MX29F1615 at first, since I have a few here.
Since they come in 42pin DIPs, they are also likely to suit those people who aren't keen on soldering 48pin TSOP packages to the adapter boards.

Will only require relatively simple changes to support the 29F800/29F160 chips. Software algorithms look pretty similar.

Cheers,
Red

[hooverphonique]

Originally Posted by Toni Wilen

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

By this you mean that the ROMEN signal isn't asserted for writes to rom regions?

[kipper2k]

Originally Posted by RedskullDC

Hi mfilos, kipper2k, Hooverphonique et al.


Sounds like a "gauntlet being thrown down" to me

I'll get to work on a 2MB Kickstart design to suit the A1200!

Will do one for the MX29F1615 at first, since I have a few here.
Since they come in 42pin DIPs, they are also likely to suit those people who aren't keen on soldering 48pin TSOP packages to the adapter boards.

Will only require relatively simple changes to support the 29F800/29F160 chips. Software algorithms look pretty similar.

Cheers,

Red

Thanks Red, that sounds great. I have found the AMD 1mb and 2mb chips for $1 each so i am going to buy them. I have no problem making these for people that would want them.

[SpeedGeek]

Originally Posted by Toni Wilen

Gayle based Amigas have 2M support built-in, extra 1M region at 0xa80000 - 0xb7ffff.

A word of caution here. The address space $A00000-B7FFFF is reserved for Zorro2 I/O space in big box Amiga's. So BridgeBoards, Picasso2 in segmented mode, Retina Z2 and some other Zorro2 I/O cards will use this address space!

So as long as you don't plan on using any Zorro BusBoards or Tower kits which provide Zorro expansion capabilities you should be OK with your small box Amiga's.

P.S. I suspect these Zorro BusBoards would generate an /OVR signal to disable Gayle from using this address space on small box Amiga's.

[Toni Wilen]

Originally Posted by hooverphonique

By this you mean that the ROMEN signal isn't asserted for writes to rom regions?

Yes, ROMEN stays inactive.

Originally Posted by SpeedGeek

A word of caution here. The address space $A00000-B7FFFF is reserved for Zorro2 I/O space in big box Amiga's.

Bigbox Amigas don't use Gayle

[mfilos]

Gief A600 1MB ROM flashable module pl0x!

[SpeedGeek]

Originally Posted by Toni Wilen

Bigbox Amigas don't use Gayle

It's also true that small box Amiga's don't have a Buster chip... but that didn't stop 3rd party developers from providing Zorro expansion bus solutions for the small box Amiga's!

[kipper2k]

I made a couple of changes, i added a switch option for A18 so that people can either add a switch on the board to toggle upper and lower area of Memory using A18 or they can run wires to the case.

So for example, using the 1mb flash, people can select the upper or lower 512k area of memory for different Kickstarts. This does not solve the onboard flashing but its progress



Here's a pic of the design.

[phipscube]

Great stuff, I like that you included the resistor for switching in +5v to A18 (R6) onboard just eliminates the need for more external components and makes installation easier, which is nice.

[kipper2k]

I ordered the boards and also the 1mb and 2mb chips, i was wrong about the price on the 2mb chips, the correct ones (she incorrectly gave me quote for 40pin version) for the 2mb chip were $3.00, still, i think an excellent price.

The resistor size on the board i believe (according to majority voice) is 4.7K. I reckon seeing as it is Christmas and mail is gonna be busy it will take about 3 weeks before i get everything i need to get started.

[Amiga1992]

So,m I got a bit side-tracked and confused there. Will this work with a piggybacked real kickstart and will we be able to flash from within the AMiga, or not?

[kipper2k]

Originally Posted by Akira

So,m I got a bit side-tracked and confused there. Will this work with a piggybacked real kickstart and will we be able to flash from within the AMiga, or not?

ATM, this is strictly an externally programmed replacement kickstart chip, hopefully with a little external logic and software it can be programmed internally. I think Toni and Red are looking at the software and any extra jumper connections. Don't forget though, that an initial image needs to be on the chip in order for the amiga to boot. I assume it may be possible to create a non copyrighted kickstart that could be used with a boot disk that contains your KS file, but i could be wrong

[phipscube]

4.7k is the generally favoured value, yes

[Toni Wilen]

Originally Posted by kipper2k

ATM, this is strictly an externally programmed replacement kickstart chip, hopefully with a little external logic and software it can be programmed internally.

I don't want external logic, I want all-in-one solution + empty socket on top for original ROMs (or second backup flash). Anything else is not good enough for me

Currently design matches not that useful (for me) "Epsilon" adapter, sorry.