DiagROM for ST

[terriblefire]

not sure how your setup is working but I had to byteswap the rom image to get it to work on the Amiga. My ST setup has hi and lo roms.

[PaulJ]

I'm burning the file as is into a 16 bit eprom. I do the same for TOS which I have compared to. Both files have the text readable which means both files are not byte swapped. I have done a byte swap and attempted execution with the same results. Out of curiousity what did you use to assemble the code? This is really strange..has to be something stupid...

[terriblefire]

It was assembled with vasm. The code is assembly anyway.

[terriblefire]

Try using the rom with Hatari before going any further

[PaulJ]

Good idea, I'll give it a try.

[PaulJ]

Hmmm.. didn't expect that... works fine with Hatari.. well at least I know I'm working with a functional image... and good hardware.. hmmm guess I'll have to figure this one out.

DM.jpg

[PaulJ]

Exxos, out of curiosity does your fast rom adaptor have the high byte in the most significant byte of the word? Guess its time to try 8 bit roms.

[exxos]

Exxos, out of curiosity does your fast rom adaptor have the high byte in the most significant byte of the word? Guess its time to try 8 bit roms.

Low bytes are first. So it goes LO HI LO HI. Nothing has been swapped out with them.

[PaulJ]

Yes, that what I would expect.

The actual memory dump from DiagROM on Hatari looks just like the image which I would expect.

DR2.jpg

Just looked through my roms for a 128k, 256k 120ns or better and came up short. Only roms I found were 200ns. Don't think that will cut it. Have to put some on order.

[PaulJ]

Problem solved, had 2 HN27C4096 120ns eproms I got off eBay from China. One died in September last year. With the remaining chip it came down to the swapped byte image I tried in the bad half of the eprom rom over and over. It was programmed on two differient eprom programmers with no faults but the upper half of the eprom will not boot any image. Swapped bytes in the lower half and it work.. All this because I didn't want to make a first attempt in a one burn only chip. Shesh!!!

Thanks