Problems burning Kickstart

[elements]

Anyone have a good seller for eeproms 27C400; 27C800 with 105ns to share?

[supaduper]

I have used these and they were fine
https://www.aliexpress.com/item/4001...30f01802bZGjrJ

[Elmo Putney]

Has anyone considered using EEPROM's instead of EPROMS to replace the kickstart chips?

Something like this:

https://www.mouser.co.uk/datasheet/2...2C-2584985.pdf

I've not looked carefully, but first scan would suggest maybe it could replace a 27C400. Surface mounted on a carrier PCB could be a nice low profile solution and no more faffing with UV erase. What am I missing?

[jlin_au]

Originally Posted by Elmo Putney

Has anyone considered using EEPROM's instead of EPROMS to replace the kickstart chips?

A commercial version is available from GGLabs (see https://gglabs.us/node/2067).

They are also available in GGLABS eBay store: search for "GGLABS F2R16" on eBay.

[Nbdy]

Hi,

Question : have 27c800 eproms ... A1200

So I can add 1MB files in eprom ... split it ... byte swap them ... double them ... burn them ...

Did someone manage to do that with 47.102 ROM's ???

Should I put the latests libs and devices in it ???

[Jope]

You can make 2MB ROMs with those. 27c400s are enough for 1MB ROMs.

[Nbdy]

Is there any tut how to make the 2MB ROM's ...

What to put in any sugestions ???

[thebajaguy]

Each ROM in a 16-bit (single ROM) configuration is a 512K bank. You burn your choice of kickstart to each bank, and you select your banks by keeping the pins for the upper address lines high or low.

Same applies for the dual-ROM systems, but you must split the image properly, then burn the half-images into the proper banks.

It gets more complicated if you play with the second $E00000 extended range options, as you have to make 2 banks appear in the native 512K of each high and low ROM.

[bluewizard]

I have a Phonesoap UV Phone "cleaner" and was wondering if anyone has been successful in getting this type of device to erase 27C400 EPROMs?

I feel like I am missing something with the UV light type or what will really erase the EPROM.

[demolition]

Originally Posted by bluewizard

I have a Phonesoap UV Phone "cleaner" and was wondering if anyone has been successful in getting this type of device to erase 27C400 EPROMs?

I feel like I am missing something with the UV light type or what will really erase the EPROM.

Quote from hackaday.com:

I used a “PhoneSoap” UVC phone sanitizer to erase an EPROM in just about 20 minutes. You should be able to find those easily nowadays.

[bluewizard]

I found one that I had bought a while ago that I forgot about. A PhoneSoap GO worked with some caveats.

I had to set the window area right over the light. It also took close to an hour to fully erase the EEPROM but it did work.

Anyway thank you for the quick response!

[Elmo Putney]

Sorry if this has been covered before, I did a quick search but no obvious/immediate answer:

If I read a rom from my Amiga (in this case a 27c400) and save it, do I still need to byte swap before flashing to another blank rom?

-My assumption is not, because I'm just replicating the bits, bytes, words, nibbles and nobchops.

[Jope]

No need to byte swap when copying existing physical ROMs.

[Elmo Putney]

Thanks Jope as I thought

[3VILC]

Good afternoon team. After reading through all this information as well as others, I'm still having issues burning kickstart roms. I'm using a T48 programmer with the correct adapter, and 27C800 EPROMs as they were cheaper and more readily available when I ordered some.
If I burn DiagROM duplicated into both halves of the ROM, works fine, if I read the original 1.3 mask ROM from the machine and make that into 1mb and burn it, also works. Yet if I try to burn the 3.2 ROMs as provided on the CD all I get is a red or sometimes yellow screen (have tried in 2 different machines), if I byteswap a 3.1 ROM image and burn that, only get a black screen.
Am I making some rookie mistake
Have tried tying unused pin1 to ground that also makes no difference

[Elmo Putney]

This I assume is on a single rom machine?

The .bin files on the CD are already byte swapped. If you read back the rom in the burner and do a file compare is it the same as the .bin file?

[3VILC]

Yes sorry should've mentioned, A2000 target machine and an A500 rev 6a for testing, so single rom machines. Yup, chips verify fine after burning. I'm absolutely baffled haha. Hence I'm certain I'm making some rookie mistake.
And correct yes, not byteswapping the 3.2 file, but have tried both ways with 3.1 and 3.2. Will do some more experiments tomorrow maybe I just have a heap of bad chips.

[Elmo Putney]

When pin 1 isn't grounded did you leve it floating? It should probaby be tied to gnd or vcc but never floating.

Did you flash KS3.2 in both upper and lower 512k of the rom so it's duplicated - that way pin1 A18 wont have any effedct either way

[3VILC]

Correct yes, A18 shouldn't be floating really but for testing should be ok as long as both banks are the same. But I tried grounding it anyway just incase. (I had been thinking of retrofitting the 42pin sockets and connecting A18 to use custom kickstarts, but I would like to know I can make a normal kickstart work first).
So yes, I have been duplicating the rom into both halves, with the EpromTool program from here, and manually in the programmer software once I worked out how to do it. I do have the chip that I used to copy a 1.3 rom which worked, blanked and set aside, since I know this chip "works"

[Elmo Putney]

So perhaps the clue is that 1.3 roms are 256k, diagrom (if I remember) is even less perhaps 128k but duplicated in the download (I need to check that), but when you move to 512k it falls over. Perhaps your A17 pin is not making contact? (pin 2). Check it back to the cpu with a meter.