emulatorII-list

Hi all,

there were no news from me for a long time, as I'm always busy doing
other things.

Disassembling of both ROM nearly finished. Main ROM does contain
memory and peripherial init, disk I/O, some serial port stuff (see 1st
request below) and a really big (for ancient times) table of initial
data for all devices in the system. Scanner ROM holds all I/O stuff as
described in the service manual and some system init, too.
Interesting solution for system init: Main CPU and Scanner CPU start
async, Scanner CPU turns LEDs on and waits for Main CPU. Only if Main
CPU passes the peripherial init, it signals Scanner CPU. Scanner CPU
then turns off LEDs and just displays "Insert diskette". That's how
the system assumes everything is ok, a reason for defect memory not
detected, as the main CPU only fills memory with 00 without really
checking.

As the ROM holds only basic functions, everything else is done via the
overlays from any diskette. That leaves some perspective to play
around :D. I finally received my Catweasel board, so next thing
is to write a char reader to dump the disks to PC and start analyzing
them.

After that: Proof that external device or software in fact is taking
full control over EII and controls everything like EII itself would
do, by dumping communication on the serial port. If it does like this,
as I assume from the code I've seen so far, the EII can be controlled
by any device with a serial port interface :-) (Assuming you have all
neccessary port interfaces and some code to come...). I always thought
that it must do so, because that's the only explanation why SDII and
the external CD-ROM (on the other port) did work at all.

Now for my requests:
1. Does anybody have ROM images earlier than the ones available here?
Please provide them, it could help a lot. The main ROM still contains
the remains of the serial monitor mentioned in the service manual,
only some bytes at the beginning are NOPed out and it will RET
immediately. I suppose it was used by setting the NMI to it to debug
the system.

2. Can anybody make a portlist from the schematics? I tried myself,
but my knowledge (and my rooms walls) is not big enough to draw it out.

3. Does anybody know a serial port monitor for PC (Linux or Win) that
only records signals coming in, without caring for any protocol? I
used to do it with my old NEC serial linemodem analyzer, but it only
outputs to its CRT, which does not help much.

That's all for now,
Hoschi