testing a Dual Rom

[ceedy]

I Have cococted a Dual Rom from MyKickstarts according to Zetro's excellent guide, sent it all off to the orient and got back 2 27C800 roms.

But only the WB 1.3 works the 3.1 is blacker than black screen wise..

Is there any sneaky way to test the combined Rom before burning ??,
just so I don't get the same result next time ?.

Chris

[mfilos]

There are several reasons that you could get that incident.
I had the same issue on my A600 but it turned out my 3.1 kickstarts wasn't the correct. Also the speed of the EPROM is important.
I had same issue in an AMD 27C400 that I tried on an A500 and a normal 3.1 kickstart that only gave black. After burning it on a Toshiba 27C400 it worked like a charm.... Go figure :S

Also, have you doubled the 1.3 Kickstart (since it's 256KB)?
You need to just:
C:\> copy /b kick13.rom+kick13.rom+kick31.rom DualKick.rom
...and then Byteswap the image in an programmer and burn.

Then you need to raise EPROM's Pin 1 and tie it to either GND (for lower bank = 1.3 Kickstart) or +5V (for upper bank = 3.1 Kickstart).
If you put it on a 3way switch... make sure that Pin1 goes to Middle Switch Pin while the other Switch pins go to +5V and GND and you're set

[ceedy]

Originally Posted by mfilos

There are several reasons that you could get that incident.
I had the same issue on my A600 but it turned out my 3.1 kickstarts wasn't the correct. Also the speed of the EPROM is important.
I had same issue in an AMD 27C400 that I tried on an A500 and a normal 3.1 kickstart that only gave black. After burning it on a Toshiba 27C400 it worked like a charm.... Go figure :S

Also, have you doubled the 1.3 Kickstart (since it's 256KB)?
You need to just:
C:\> copy /b kick13.rom+kick13.rom+kick31.rom DualKick.rom
...and then Byteswap the image in an programmer and burn.

Then you need to raise EPROM's Pin 1 and tie it to either GND (for lower bank = 1.3 Kickstart) or +5V (for upper bank = 3.1 Kickstart).
If you put it on a 3way switch... make sure that Pin1 goes to Middle Switch Pin while the other Switch pins go to +5V and GND and you're set

Yup done all that.. did 2 different sessions, grabbed the roms twice , Combined files twice with the 2 different ( all winuae tested) rom grabs..

I followed zetro's guide exactly , doubled up the 1.3 to get correct file size. and its all went ok .. with no errors or problems reported ,

but both eproms give the same result.. 1.3 ok 3.1 black ?? ..

That's supposing the codes were burnt ok before sending to me ??.

I'm Just asking if I can do extra checks & I can avoid buying a programmer ( altho' would love to ).

I will check the eproms wen I get home to see what make they are, they are 100ns devices as I recall .

thanks for the reply

Chris

[kipper2k]

whats the link for Zetr0's guide ?

[Zetr0]

I has a guide?

sweet!


@Ceedy

Which 3.1 ROM image did you use?

if you used a hacked or cloanto ROM image, these wont directly work on a native Amiga.

As our good friend mfilos has pointed out, you need to split both ROM's

I am suspecting that the 1.3 ROM has the added extra of IDE compatibility thus is larger than the standard 1.3 of 256KB

Both ROM files need to be split odd and even and then doubled up for both chips, you will need to ensure that when the Upper half of the chip is not selected that it is Grounded and when selected there is a hold of +5v with a 4k7 resistor to +5v

[kipper2k]

Originally Posted by Zetr0

I has a guide?


sweet!

haha, i thought i would have found it by now

[mfilos]

Check your PM Ceedy mate

Btw I made a small guide here as well along with schematic...
http://www.amibay.com/showthread.php...884#post143884

[ceedy]

Originally Posted by kipper2k

haha, i thought i would have found it by now

ah well you see you just haven't understood the special code i was using..

Zetro via the enigma = kipper2 ... obvious init !! ..


Groveling X 10 to kipper2 for the cockup !!

chris ( its the age! that does it! )