Problems burning Kickstart

[alexh]

Some Amiga's cannot take 512Kbyte chips without hard modification.

[alexh]

Some Amiga's cannot take 512Kbyte chips without hard modification. Rev6.0a should be fine though, I am sure it was 5.x

[TheCorfiot]

Originally Posted by alexh

Some Amiga's cannot take 512Kbyte chips without hard modification. Rev6.0a should be fine though, I am sure it was 5.x

A500 Rev 5.x need a soldered wire link and a pin left out of the socket on the new ROM.

Rev 6 onwards need no mod to the ROM (Or A2000 Rev 6 onwards)

TC

[caver99]

right, ok, i now have winhex, i am lookinag at putting 1.3, 2.05 and 3.1 onto a single chip, what would be the best chip, which pins do i need to switch and how the hell do i do this bit switching in win hex,
Oh and Hello everyone!!!

[alexh]

Helps if you tell us what Amiga it is for. 16-bit (A500/A600/CDTV/A2000) or 32-bit (A1200, A3000(T), A4000(T), CD32)?

You'll almost certainly need 27C800 (two for 32-bit)

They are 1Mbyte each and so can hold two (512Kbyte) Kickstarts (16-bit Amiga's) or a pair can hold four kickstarts (32-bit Amiga's).

If you need more then you'll need 27C160 chips.

Toni Willen's CDTV once used a 27C160 chip with four kickstarts.

[Toni Wilen]

CD32

CD32 is a special case, it has only single 16-bit ROM. (cheap...)

what would be the best chip

1 EPROM (16-bit) and 4 Kickstarts = need at least 27C160.
2 EPROMs (32-bit) and 4 Kickstarts = 27C800 (27C160 works too)

68000 based Amigas: 150ns is ok. 68020+, need 120ns or faster.

[caver99]

Sorry, i have both an A1500(A2000) and and A1200.
Its the A1500 that i would like to put the multi kickstart into.

[caver99]

so how do i do a byte swap?

[coze]

you can do at willem program (load rom, action - swap byte)

[Gavilan]

Guys, im following this very interesting thread...being totally newbie with this issues...where do you buy the 27C800 and all the other chips? Is there any website to buy online? Because in my country its impossible to get them...and how much do they cost??

and going deeply into the multikickstart rom..how difficult is to build one for an Amiga 1200 or A600?

Has anybody done such an experiment before? How does it work?
Where can i get more info on the subject?

Kind Regards
Sebastian

[rkauer]

Sebastian!!!!

Welcome, mate!

You can find those little babies on Ebay.

IC-China is the regular seller. Just beware that commonly 1 in every 4 chips are defective (at least!). But they are dirty cheap, and so are the postage costs.

[amigamaniac]

You can buy blank UV erasable EPROMS from me if you like. I have LOTS of them available. They are refurbished, but in as new/mint condition. Details and photo are on my website http://www.amigamaniac.com

If you want 27C400 EPROMS, these are a substitute. If your EPROM programmer can program 27C400 EPROMS, these will work 100%. I know because I have backed up all versions of my original (1.3, 2.05 & 3.1) KS ROMS onto three of these.

Nathan

I have just read this thread today with great interest. I have an Amiga 3000 with a 6.1 rev motherboard and also bought a set of 3000 3.1 roms off ebay. of course they dont work. it had the original roms in U182, U183 which are 27C200 128x16. No rom tower in this unit. The ones I got off of ebay are Toshiba TC574200 256 x 16 roms. They are labeled for sockets U180, U181. Nothing but a black screen with these. Have twiddled all the jumpers for speed, etc. Question is how can I make these work - assuming they are programmed correctly.

[Vars191]

You must have bought them from the same place I did
Same result
Please HELP

[Vars191]

what eprom do you use for a 3000t and 3000

[alexh]

Originally Posted by mikef

Question is how can I make these work - assuming they are programmed correctly.

The 27C200 (which are EPROMs not ROMs) and TC574200 (also EPROMs) are pin compatible so either

a) You've got them back to front, swapped round
b) They are not programmed correctly

I favour (b)

[amigamaniac]

@alexh

You seem to be quite expert on all things Amiga :-) So the ROMS/EPROMS used by the A3000 and A4000 are the same part/compatible with the other Amiga's? I know that they have their own specific KS ROM image/data, I'm just asking if the parts are the same/pin compatible I suppose.

What about programming the EPROMS for A3000 & A4000, would it be the same process for programming the two EPROMS for A1200? Again, I know? that the three 32-Bit Amigas have their own unique KickStarts, and are not interchangable with each other.

I have successfully backed up my A1200 ROMS also (besides A500 & 600), so it is not a difficult process :-)

Nathan

[alexh]

Almost all Amiga's support the 27Cx00 chips.

SOME early A3000's need a ROM TOWER to use 27Cx00 chips

27C200 = 256Kbytes each
27C400 = 512Kbytes each
27C800 = 1024Kbytes each

KS1.3 = 256Kbytes
KS3.1 = 512Kbytes

16-bit Amiga's need 1 chip. 32-bit Amiga's need 2 chips.

Examples:

A500,A600, B2000, CDTV KS1.3 = 1 x 27C200
A500,A600, B2000, CDTV KS3.1 = 1 x 27C400

A1200/A4000 KS3.1 = 2 x 27C200

You can use bigger EPROMS than you need i.e. you can use 2x 27C400 EPROMs with A1200/A4000 but 50% of each will go unused. You could even wire up a switch to the appropriate address pins and have a KS switcher.

I personally only ever buy 27C400 chips.

If you are going to make KS3.9 EPROM's for A1200 I'd be curious to know if you can successfully 2x27C400 chips working with expanded 1Mbyte images using later exec's. I've read/heard rumours about people successfully making it work but never seen the process from start to finish.

If you could go through step by step with Doobrie's tools (ROMSplit & Remus) explaining exactly what files inside kickstart you were upgrading and to what version etc. I'd find it very very interesting.

[Toni Wilen]

Originally Posted by alexh

If you are going to make KS3.9 EPROM's for A1200 I'd be curious to know if you can successfully 2x27C400 chips working with expanded 1Mbyte images using later exec's. I've read/heard rumours about people successfully making it work but never seen the process from start to finish.

ROM maps like this: (tested with 2x27C160, left side is single ROM address, multiply by two to get "real" address)

1M

00000 - 3FFFF = 000000 - 07FFFF (chipram overlay)

00000 - 3FFFF = E00000 - E7FFFF
40000 - 7FFFF = A80000 - AFFFFF
80000 - BFFFF = B00000 - B7FFFF
C0000 - FFFFF = F80000 - FFFFFF

512K

00000 - 3FFFF = 000000 - 07FFFF (chipram overlay)

00000 - 3FFFF = E00000 - E7FFFF
40000 - 7FFFF = A80000 - AFFFFF
00000 - 3FFFF = B00000 - B7FFFF
40000 - 7FFFF = F80000 - FFFFFF

NOTE: Blizzard maprom enabled = Only F80000-FFFFFF available)

[amigamaniac]

@alexh

Thanks for the speedy reply :-) I have a 512k KS 3.9 ROM image, which I programmed to two of the ROMS I have/use/sell. As you would know, they are 100% pin compatible with the 27C400. I used the method outlined in this very thread - with WinHex. Like it instructed in this thread, I just fill the other half of the EPROM with the same data. Anyhow, the 3.9 EPROMS worked just fine in my A1200. The KS 3.9 image also worked just fine in WinUaE. I also have KS 3.5 I think, but I'll have to look on my other PC to be sure.

It sounds like the ROMS/EPROMS? bought from ebay were either programmed wrong, or the people that bought them need a ROM tower. If they are original, then it is a ROM tower issue more than likely. A3000 seems to be a PITA when it comes to upgrading ROMS. I also read somewhere that some A3000's wont take 3.1 ROMS no matter what. I can't see that being true though. Anyhow, for those two unlucky people, if they are EPROMS (looks like it from the photos), I am more than happy to erase them and re-program them for free. Of course you would just have to pay for postage ;-) I would program them using exactly the same method I use for A1200 ROMS (but with the A3000 3.1 image of course - which is NOT the same as the A1200 3.1). I can't see why it would have to be done in a different way. But maybe I am wrong? Has anyone ever backup up their 27Cx00 ROMS for an A3000? Or can confirm that the A1200 method works?

Nathan