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Re: [N8VEM-S100:3631] Re: Run of Dual CF-Card/Hard Disk IDE S-100 Boards



David -

The "power up" default seems to be Drive "A". If I run the MYIDE (single drive version) I can access/format/read/write drive "A".

If I use the rom monitor to switch to Drive "B", then run the MYIDE (single drive version) I can access/format/read/write drive "B".

If I use the drive select code I sent along I can switch from "A" to "B", but not back again. If I then "Break" back to the monitor I can output 00H to 34H, reselecting "A" without any problem and it will work fine with MYIDE as drive "A".

Why I can change "A" to "B" with the software, but not "B" to "A" is confusing. Why it works fine in the monitor is even more strange.

I'm wondering if the ADC SuperSix doesn't completely decode I/O addresses, or maps things differently when the ROM is enabled??

- Gary

On 5/11/2014 3:43 PM, David Fry wrote:
Hi Gary,
Just to clarify, You saying that once Drive 'B' is selected you are unable under the software to switch back to Drive 'A'.

Do you mean you are unable to read the Drive 'A' CF card after switching back to Drive 'A' or does the drive select LED not change from 'B' to 'A' ? Afterall the drive select mechanism is just a D type flip flop mapped to a port !!
I cant see anything leaping out at me from your code snippet.
Regards
David Fry