KS ROM sizes

[Generale]

Hi there. Just asking about the size of the different verions of the KS roms.
First: Is it true that 1.x and 2.x are 256k and 3.x is 512k? This is what I have been told, but my ks rom images are all 512K with no sign of padding at the end.

Second:
Are the KS ROMS 16 bit? Which would mean that ks 1.x and 2.x are 256Kwords = 512kbytes?

I'm just asking this because I don't know and it's been bothering me.

[Linchpin]

AFAIK all roms are 512k.. its just that some are 2x256 and the others a 1x512... but im prolly wrong :-D

[mjg59]

2.x and 3.x are both 512K. 1.x are 256, but repeated again in the next 256K of address space. UAE dumps often end up as 512K as a result.

On 16-bit machines, the ROMs can be accessed 16 bits at a time. However, they're still 256 kilobytes long. On 32-bit machines, they're split into two chips. Each can be accesed 16 bits at a time, allowing for the transfer of 32 bits of data in a cycle. This doesn't alter their length.

[Generale]

Righto.
So the KS roms on the 16 bit machines are 16 bits wide and totalling to 256kb for 1.x and 2.x but 512kb for 3.x.

Hmmmm...Don't mind me. Just thinking....If some individual happened to have a couple of 8 bit flash roms, a new KS could be created if every second byte were burned to one rom, and every other to the second. Simple circuitry to attach.... Cough. Not that I'd consider something like that. Especially for patching the ROM.

[bloodline]

Generale wrote:
Righto.
So the KS roms on the 16 bit machines are 16 bits wide and totalling to 256kb for 1.x and 2.x but 512kb for 3.x.

Hmmmm...Don't mind me. Just thinking....If some individual happened to have a couple of 8 bit flash roms, a new KS could be created if every second byte were burned to one rom, and every other to the second. Simple circuitry to attach.... Cough. Not that I'd consider something like that. Especially for patching the ROM.

No...

1.x = 256Kb

2.x and 3.x = 512kb


Some Roms are on a single 16bit chip (for the 68000 machines), and some are on 2 16bit chips accessed as a single 32bit chip (for the 680x0 chips).

[Generale]

hehe. Oops. Yeah. Sorry. I wasn't looking as hard as I should have been. Still, there's no reason why I..I mean someone couldn't use 2x8 bit in parallel as a 16 bit is there? I can't see one.

[bloodline]

Generale wrote:
hehe. Oops. Yeah. Sorry. I wasn't looking as hard as I should have been. Still, there's no reason why I..I mean someone couldn't use 2x8 bit in parallel as a 16 bit is there? I can't see one.

You could do that, providing the votages match that of the 16bit one.

[Doobrey]

Generale wrote:
Still, there's no reason why I..I mean someone couldn't use 2x8 bit in parallel as a 16 bit is there? I can't see one.

Nope, no reason.. it`s exactly what RedSkull did ..have a look on aminet for kf500.lha
 I did the same thing myself using 2x16 bit flashs on my A1200.

In fact, why not just get a 16bit flash and save yourself a load of soldering?

Ooh, and just to be completely retentive,
 The CD32 is a 32bit machine(duh!) but uses a single 512x16 rom (1MB)

[cartmanau]

While we are on the topic of KS ROMs, what flash chip is compatible with the MX23C4100?

[Generale]

What voltages are the bus/roms operated at normally?

Tried finding 16 bit roms. I swear, all the useful things are made hard to get for australians. Might as well say my idea while I'm here...

I have 2x4mBit(512k)x8bit Flash ROMs.
I had a realisation.
It would be perfectly feasible to put a couple of KSs on the roms, like 2 and 3. I've been trying to think of a valid reason to keep 1.3, but I can't think of one. Anyway, they could easily be switched with an addressline.

 The closest I could find on Aminet was DC-KF500.lha Is this it?

[Generale]

cartmanau wrote:
While we are on the topic of KS ROMs, what flash chip is compatible with the MX23C4100?

It really depends on what you mean by compatible. Do you mean capacity/data width/pinout compatible?

[cartmanau]

@Generale
I agree, everything in AU is a pain in the a$$ to get. You want to live in the country (esp. with our old and mutual friend normie closing down )

The ROMs are operated at 5V in an Amiga.

The DC-KF500.lha package is the guide on putting flashes into an A500.

When i mean compatible, I guess I mean the same size and package (if the package isnt the same or is hard to get then that could probably be modded as long as it works).

[RedskullDC]

cartmanau wrote:
@Generale
I agree, everything in AU is a pain in the a$$ to get. You want to live in the country (esp. with our old and mutual friend normie closing down )

The DC-KF500.lha package is the guide on putting flashes into an A500.

Not exactly true.

www.futurelec.com based on the NSW Central coast keeps all kinds of esoteric flash chips.

I'm planning on updating my DC-KF500 package at some point soon with A1200/A4000 circuits.
Just ordered a couple of SMD 2MB 16bit wide flash chips from Futurelec to play with.

Will be able to hold a few KS images which can be swtich selectable.

Cheers,
Red @ Digital Corruption

[RedskullDC]

Oops,

That link should have been:
http://www.futurlec.com/

Red

[bloodline]

RedskullDC wrote:
Just ordered a couple of SMD 2MB 16bit wide flash chips from Futurelec to play with.

Will be able to hold a few KS images which can be swtich selectable.

Don't flash chips usually work at 3.3 Volts?