1Mb kickstart ROM in A600 possible?

[Turran]

Greetings.

Short question, does the A600 support 1Mb kickstarts?

Long question: I've been making my own roms for a little while and following mfilos excellent guides ( http://mfilos.blogspot.se/p/guides.html ), this has been successful in my A1200 and A4000 with 3.1 roms with updated scsi.device and a full 3.9 rom with BB4 + updates.
All good.

I figured I'd do a 3.1 kick with updated scsi.device for my A600 but I can not get it to work when I go from 512Kb to 1Mb rom.

If I make a normal 3.1 512Kb kickstart rom it works fine.
If I move to a 1Mb rom the amiga 600 does not give any picture.

I follow the guides of course. Putting exec_40.10(A500-A600-A2000) at the top, followed by 1MB_ROM
I include all files but workbench.library (does not fit with updated scsi.device).

For the extended rom I just put:
romheader
DummyCDstrap
workbench.library_40.5

All the same as I've done with the A1200 and A4000, except the files are of course from a A500/A600/A2000 kickstart rom.

In Remus, I run the Make_1MB_ROM and select A500/A2000 so that I get one 1Mb kickstart file instead of a HI and LO one.

The 1Mb kickstart file works fine in WinUAE with a A600 configuration loaded. I just load it in the eeprom burner, perform a byte swap and burn it. No picture in real A600.

Any clues? =)

[Arnie]

I tried this with a 27c800 & 27c160 and I couldn't get it to boot, just got the kickstart screen. I gave up in the end.

[Turran]

I cant even get to the kickstart screen, thats why I'm extra curious =)

[Toni Wilen]

Include first 16 bytes or so (preferably in hex) of both roms.

WinUAE does not emulate initial program counter exactly because there are bad custom roms made only for emulation and I don't want to break them

[Turran]

Here are a few =)

Normal 512Kb 3.1 rom. Works in WinUAE (and burning later)


The same Normal 512Kb 3.1 rom, byteswapped and burned. Works in real amiga.


1Mb 3.1 rom, Works in WinUAE.


The same 1Mb 3.1 rom, byteswapped and burned. Does NOT work in real amiga 600.

[Toni Wilen]

EPROM size? 1M or 2M? Attach also start of second 512k ROM (at the middle of 1M rom image)

[Turran]

EPROM 27C400 (4Mb?!)

There is no second rom as this is a A600 (only one slot), however, before merging into 1Mb rom:

Standard 512kb rom, not byteswapped:


Extended 512kb rom, not byteswapped:

[Toni Wilen]

I meant virtual second 512k rom (512k extended + 512k normal).

Both looks fine too. (EDIT: I read 4M, not 4Mb, never mind..)

[Turran]

Hrmp. Weird then.

For fun I made a 3.9 rom as well, same as for A1200 but source files from A600 3.1 kick rom of course. It wont start with that either.

Also tried a standard 3.1 512Kb rom that works and made a 1Mb rom out of it. No go on that either.

Not the end of the world. Guess I'll stick to a non modified 3.1 512Kb rom then. Thanks for looking into it Toni =)

[Toni Wilen]

Originally Posted by Turran

HAlso tried a standard 3.1 512Kb rom that works and made a 1Mb rom out of it. No go on that either.

Do you mean you took non-modified 512k 3.1k rom image, did "copy /b original.rom + original.rom 1m.rom", byteswapped it and it didn't work?

[Turran]

Nope. I meant I took a normal 512k 3.1 rom, RomSplit it into files and created two 512k roms, merged together into one file (same procedure as when you create 1Mb roms for A12000 etc) in remus, byteswapped it and it didnt work.

I could try and copy two together as well. If that does not work, something is a miss with my A600 and it does not like 1Mb roms at all.

[alexh]

Originally Posted by Turran

EPROM 27C400 (4Mb?!)

27C400 is 4Mbits which is 512K Bytes.

You need a 27C800 (8Mbit) to store a 1M Byte ROM.

[Turran]

Oh right! That would explain it. hehe. I was sure 27C400 stored 4 MegaByte. Foiled again! Why did the burner not complain then. Weird.

http://www.sanitaryum.com/wp-content...iled-again.jpg

[RedskullDC]

Hi Turran, et al.

Originally Posted by Turran

Oh right! That would explain it. hehe. I was sure 27C400 stored 4 MegaByte. Foiled again! Why did the burner not complain then. Weird.

http://www.sanitaryum.com/wp-content...iled-again.jpg

Your software probably just wrote the first 512KB out to the 27C400?

If that's the case, your 68000 would just see an endless loop when it executes the code at $00000002 (when the OVL signal is active):

4E F9 00 F8 00 02; JMP $F80002.

Which is pointing back at itself once the OVL signal is disabled

I've just uploaded a file to the zone you may find useful.
In EXCEL format (sorry).
Just some notes I made while working on the forthcoming FlashROM project for the 600/1200 ...

Cheers,
Red

[Turran]

Very interesting. Thanks a bunch !