4MB of CHIP - is it possible?

[JackTheKnife]

I have ICD AdRAM 540 with 4MB of RAM and A500 rev.5 w/ Super Agnus. I can ease do 1MB CHIP + 3MB of the rest, but is there any way to mobo mod to allow recognize whole 4MB as CHIP mem?

[Zetr0]

alas no,

the best you can do after upgrading the Agnus, Denese etc is 2MB of ram, thats the maximum that the 8372b and 8375 Agni can do.

[JackTheKnife]

Strange, but one dude on Polish Amiga Forum was asking about running Kickstart 3.1 with 4MB Chip (he has A500 rev.6).

Anyway I have Super Agnus but I do not remember version of "her" and Denise. I will check after I will back home.

[alexh]

Unless he has a modified MiniMig or WinUAE he's mistaken / lying.

He may have 4Mbytes of RAM but it will be 2MB Chip and 2MB FAST.

No existing Amiga chipset can access more than 2Mbytes of Chip RAM

Also you cannot use a 2Mbyte SuperFat Agnus with a rev.5 A500 without an extra bit of hardware, a MegAChip or MultiMegi etc. (a board with the Agnus + 1Mbyte RAM on it which plugs into the Agnus socket and clips to a few chips)

[JackTheKnife]

Here is the question from Polish Amiga Forum:

When I burned Kickstart 3.1 and 2.04, the machine didn't start. Instead of picture of flying diskette I had the black screen. I waited for 5 minutes, but no result... But paradox: when I burn Kickstart 1.2-1.3, the machine starts well. I think, that problem goes from additional chip mem. I have revision 6A and 8 chips of ram. I have changed JP7A and JP2. Workbench see RAM well, but when i reset my Amiga, it is Guru Meditation. After click picture appears (Insert Workbench 1.3). Who can help me?

So how he did this? And can anybody help him? He is using AT49F040-70 EPROM

Back to my situation with AdSpeed. Does AT49F040-70 will work with 14MHz A500 or it is too fast EPROM?

[alexh]

His problem is that his kickstart is too big (512Kbytes) for his motherboard without modification. OR his EPROM is too slow just like yourself. He certainly doesn't have 4Mbytes chip RAM it is impossible.

[yaqube]

Originally Posted by JackTheKnife

So how he did this?

He didn't.

I have revision 6A and 8 chips of ram.

He said he had 8 DRAM IC's (that's 1 MB) on his motherboard, not 8 MB of chip memory.

Cheers!

[Hungry Horace]

Originally Posted by alexh

OR his EPROM is too slow just like yourself.

comeon alexh, just because you're better informed on hardware matters than most, is there any real need for that sort of comment?

i admit, it did tickle me, but show a bit of love at xmas man

[alexh]

I meant "yours". This was a fault he's been experiencing.

[BYTEMAN]

Originally Posted by alexh

His problem is that his kickstart is too big (512Kbytes) for his motherboard without modification. OR his EPROM is too slow just like yourself. He certainly doesn't have 4Mbytes chip RAM it is impossible.

Excuse me, but it was I. (excuse me for my poor English ). Please, explain me what modification I need to do with my board. I use KickFlash-500 device.

Best regards, Alexander.

[Doobrey]

Originally Posted by Sasha

Excuse me, but it was I. (excuse me for my poor English ). Please, explain me what modification I need to do with my board. I use KickFlash-500 device.

Your Rev 6A should take a 512KB ROM without any mods, and the 70ns flash is easily fast enough to use. I'd say the problem is in the way you built the KF-500.

Short answer:
Since it works with KS1.3(256KB) but not 2.x or 3.x(512KB) I'd look again at A17 on both Flash chips, it should go to pin 1 on the original ROM socket on a Rev6 board, and NOT on pin31 as the old Rev5's had it.

Boring answer:
Pin 31 on Rev6 is tied to +5v(to put '8/16 bit ROMs into '16 bit output mode'),so hooking A17 to it would result in you being limited to 256KB ROMs.. so when you wrote the 2.x or 3.x ROM image the lower half of the image got overwritten by the upper half.. result= black screen as the CPU gets stuck in an endless loop.

[BYTEMAN]

@Doobrey: Thank you, I will check this. I can explain my problem more exactly only in Russian (excuse me).

Я узнал от бывшего владельца Амиги, что кикстарт 2.04-3.1 работал только при замкнутом JP2 (нижние 2 контакта, когда активировано только 512к Chip Ram). Возможно, что из-за этого у меня есть проблема со сбросом компьютера. I think, this information will be useful.

[prowler]

Originally Posted by Sasha

Я узнал от бывшего владельца Амиги, что кикстарт 2.04-3.1 работал только при замкнутом JP2 (нижние 2 контакта, когда активировано только 512к Chip Ram). Возможно, что из-за этого у меня есть проблема со сбросом компьютера.

Hi Sasha,

It's good to have you aboard.

I have a suggestion for when you are struggling to explain yourself other than in Russian.

I have just copied your Russian text from above into the "Translate a block of text" panel at the Babel Fish translator:
http://babelfish.altavista.com

Then I selected 'Russian to English' as from and to languages, and then clicked the 'Translate' button.

The following text was given as the translation:
"I learned from owner [Amigya]'s that been, that [kikstart] 2.04-3.1 worked only with locked JP2 (lower 2 contacts, when activated only 512[k] Of chip Of ram). It is possible that because of this i have a problem with the discharge of computer.",
which I copied back here.

With a bit of tidying up this would give you a much better message with which to get a quick response here.

Try it yourself next time.

Good luck.

[BYTEMAN]

Ok, thank you.

[prowler]

Originally Posted by Sasha

Ok, thank you.

You're most welcome.

[kolla]

Originally Posted by prowler

With a bit of tidying up this would give you a much better message with which to get a quick response here.

Or better yet - post both, on the not so odd chance that someone who actually do know russian is also reading. Not that I put myself in that group... yet

[JackTheKnife]

I can read Russian too