Removed the JP1 jumper, and put it back on while the machine was on (to erase the ROM??).
You only need to do that if the contents of the XT-IDE ROM are stopping the computer from booting.
And at address E000 I find something with "ROMDOS 1.0" in it's description... probably the DOS 3.31 ROM?
Yes.
So this probably interferes with flashing?
I can't see how.
The only implication I can think of is that an XT-IDE starting address of E0000 won't work (due to address conflict).
Any ideas? I should think a successful flash at CC00 should mean the BIOS should be available
Depends how the verification is done.
A example. A verification after each block write is susceptible to the following problem.
Step 1. Write "ABCDE" to block 0
Step 2. "ABCDE" read back from block 0 - verification good
Step 3. Write "FGHIJ" to block 1
Step 4. "FGHIJ" read back from block 1 - verification good
Step 5. Write "LMNOP" to block 2
Step 6. "LMNOP" read back from block 2 - verification good
Step 7. Write "QRSTU" to block 3
Step 8. "QRSTU" read back from block 3 - verification good
Verified okay, but it turns out that there is an addressing error - bit 2 stuck low.
So when the data is viewed, what is seen is
Read of block 0: "LMNOP" <---- Bad ("ABCDE" initially written but later overwritten by step 5)
Read of block 1: "QRSTU" <---- Bad ("FGHIJ" initially written but later overwritten by step 7)
Read of block 2: "LMNOP" <---- A read of block 2 is actually reading block 0
Read of block 3: "QRSTU" <---- A read of block 3 is actually reading block 1
XTIDECFG verified the ROM contents after it was written,
Is that verification done after each block write, or done after the entire file is written?
That's a totally separate issue to ROM content.
I know that the ST11 worked, and that certainly suggests that a ROM at C8000 is called.
You could 'ram that home' by the process I posted at post #34