Chema wrote:I think there were more than just two versions of the v1.1 ROM. Must have a look in my old files. Anyway, I do have one of the earliest versions (I think it is the v1.1a) and cumulus works quite nicely; except for the fact that I have to reboot a couple of times for it to start working properly (sometimes even the Cumulus itself hangs), and the problem I experience with the keyboard on some games from Twilighte.
However, indeed the changes were mostly on the tape loading routines (V1.1a still checked for parity errors, while v1.1b and c just ignored them). I don't think this should interfere with the Cumulus. At least not in the way that it cannot boot the DOS. But who knows.
I tried to make a small program to test the behaviour of the Cumulus vs the emulation of Microdisc. It measured the read/write errors to disk and overlay ram and I got none in all the attempts. I also tried to measure the reading/writing times, but I failed to do it properly so I have no reliable results. However it seemed to me that the timings where quite different in the real machine and in the emulators, and what seemed more interesting, in the real machine they seemed to vary quite a lot.
I don't know how Cumulus emulates the read/write operations, and also don't know if these varying timings may produce some kind of side effect. Anyone studying the firmware can bring some light to this?
I am not aware of version other than 1.1a and 1.1b of the Atmos ROM, but if you suspect you have another version, dumping the ROM is the only way to be sure. With the cumulus it will become easy to dump the ROM to a floppy and get it back on the PC, without even the need to unmount the ROM
When I speak about rework is the hardware changes done to an Oric, they could be multiple, like the official one on the reset line, tape or video output, or more "custom" like some changes on Phi2 on some OricFrance build device.
It is really important to know how and what your oric have inside, because anything could have an impact on the memory bus and the expansion bus.
Replacing the DRAM is one of thoses changes of course