Epson PF10 problems
dave04a at dunfield.com
Thu Dec 22 17:03:16 CST 2005
> Other (related) things that I am looking for....
> 1) The plastic ROM carriers. These are plastic mouldings that you put a
> DIP-packaged EPROM into, then crimp the pins over. The same carriers were
> used in the Tandy M100, and I think 24-pin versions were used in that
> Panasonic hand-held machine that gets mentioned here. I need the 28 pin
> ones, I think Molex once made them.
Don't have any spares unfortunately - but FWIW, I believe it is possible to insert
ROMs without them (not great, but possible). I believe I have seen a reference to
this somewhere on the web.
> 2) Is the PX4 technical manual on the net anywhere (I've found the PX8
> one already). The thing I need most at the moment is the pinout of the
> cartridge connector. I have a 3rd party 512K (!) RAMdisk module there
> which doesn't seem to work.
I'd be interested in any of this info as well.
> The ROM sits in the second half of the address space (it's an 8K ROM,
> 27C64, and it's enabled when A15 is high. It's ghosted 4 times). If this
> is like a 68xx, I would expect vectors at the very top of the address
> space, with the highest one of all to be the reset vector MSB first.
> This ROM contains what looks like code in the first half or so. Then a
> large block of FFs. And then the vectors. The very top one is 'E000'
> which would point to the first byte of the ROM. Most of the others are
> EExx, again in the 'code-like' part of the ROM.
I agree - this sounds like a 68xx architecture.
> > If you can get the exact CPU type, I may have a disassembler that will
> > let you peek into the startup code a little better.
> It's an HD6303X. I can look up all the letters (things like the clock
> rating) if you need them, but that should be enough. In any case, writing
> a disassembler is not going to take me too long if I need to do it.
I don't have a Hitachi data book handy, although I know there are some
"somewhere" in the workshop - I'm guessing that this is a second-source
of a Motorola 6803, which is essentially a ROMless 6801, which is a
slightly enhanced 6800.
If all of the above it true, I can give you both an assembler and disassembler
(runs under any DOS compatible environment) for the 6801 which should
cover the instruction set. Let me know if you want them and I'll send by
> Fortunately I do have an EPROM emulator. This is a good idea, well worth
> trying. Next thing is to get out the datasheets and find the opcodes for
> jmp and nop ;-)
Assuming it is a 6801/03 compatible CPU:
E000 7E E0 00 2 JMP *
E003 01 3 NOP
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
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