Re: Copying ROMS ?

Nope! No manufacturers mark. Only the numbers given beow and a date
code like A27 119.

But like I said, I have two HX-20. One has the BASIC ROMs, the other
has 27C64 EPROMs. I just can't read the BASIC ROMs into my Data I/O
PROM Programmer. Not sure of family/pin code. I have tried all of
the 8K codes, with no luck.

I also tried swapping them (not sway :-) but there appears to be
something else at play here that I'm not familar with. When I pull
all of the BASIC ROMs, the system still runs BASIC (with no ROMs at
all). Only way I can see this is if there was some code pulled from
ROM and resident in the HX-20. Epson did this with the PX-8 but
there is no mention in the manual and I can't force a reload.

I'm asking some HX-20 experts but have not heard back yet.

> Is there a manufacturers mark on these ROMs? Is it possible they are
> Motorola? Motorola had some ideas about Eprom/Rom compatibility that
> wasn't shared by Intel and others and Motorolas' design did not catch
> on. Motorola was (it seems) more aligned with TI in those days (both
> from Texas?) and were also making 2564's that have a different select
> pinout than 2764s. Do the 2764 Eproms work in the board that has these
> mystery ROMs?
>
> On another note, I hope it isn't too hot where you are - you mention
> swaying the ROMs and I'd hate to think you were succumbing to the
> weather... ;-) Heatstroke? (going back into hiding...)
>
> John:-#)#
>
> At 08:12 AM 22/06/2002 -0700, Mike Davis wrote:
>
>
> >Like I said below:
> >EPSON BASIC1R0 M64020AA
> >EPSON BASIC1R0 M64021AA
> >EPSON BASIC1R0 M64022AA
> >EPSON BASIC1R0 M64023AA
> >
> >The other writing is simply date code information.
> >
> >The thing is, like I have said, I have a 2nd HX-20 that has 27C64s
> >installed. So, I was going to copy the BASIC to 27c64s and use in
> >the 2nd unit to have a BASIC machine.
> >
> >Someone suggested that the masked ROMs might have some sort of
> >special non-standard select method within the ROMs. But if that was
> >the case, the 27C64 wouldn't work, unless there was some difference
> >in the board (No PALs on this board). I'm going to disassemble it
> >today and see if the 2nd unit has some rewired ROMs.
> >
> >But, I have a 2nd problem that I'm trying to work off of this board.
> >I pulled the BASIC ROMs from the 1st unit and performed a hard reset,
> >clearing RAM. Still ran BASIC and the monitor program that were
> >supposed to be in ROM (ROMs were completely out of the system).
> >
> >I was going to simply sway ROMS and see if they worked in the other
> >system but for some reason, the systems behave the same, regardless
> >of which set of ROMs is in either machine.
> >
> >I thought perhaps the program is loaded into resident memory but the
> >manuals don't mention this and I don't know how to force a reload. I
> >know their other machine, PX-8, behaved this way.
> >
> >
> > > Is there any common numbering on the masked parts that might give
> > > a clue as to what they REALLY are?
> > >
> > >
> > > Mike Davis wrote:
> > > >
> > > > That was the first thing I tried. It read in all blank. That
> > > > is the problem that I'm trying to resolve.
> > > >
> > > > > If 2764s are known to work just read the ROMs as 2764s.
> > > > >
> > > > >
> > > > > Mike Davis wrote:
> > > > > >
> > > > > > I have verified that I can read and write other 27c64s and I
> > > > > > also tried swapping ROMS however there is another small
> > > > > > glitch.
> > > > > >
> > > > > > Apparently the HX-20 runs the programs out of RAM. I guess
> > > > > > it loads from PROM and runs from RAM. I removed all of the
> > > > > > BASIC ROMs and performed a hard reset and when it comes
> > > > > > back, it's still running BASIC, without the BASIC ROMs even
> > > > > > installed. Wierd!
> > > > > >
> > > > > > I have looked through the manuals to try and find a way to
> > > > > > force a reload but no go (so far). I might try removing the
> > > > > > internal batteries and see what happens.
> > > > > >
> > > > > > The manual also mentions that one can use 27C64s in the
> > > > > > HX-20. There may also be one other thing that is causing the
> > > > > > problem. I am trying to read the ROMS using family/pin codes
> > > > > > for other ROMS. I don't find that part number and have
> > > > > > tried a number of other 8K ROM fam/pin codes and none give
> > > > > > me anything but blank loads.
> > > > > >
> > > > > > Perhaps that is part of the problem?
> > > > > >
> > > > > > Mike
> > > > > >
> > > > > > >
> > > > > > > Verify that you can read another 2764 (incase you have
> > > > > > > reader problems).
> > > > > > >
> > > > > > > Can you swap the 2764 for the Masked ROMs & work without
> > > > > > > changing jumpers/settings/wiring?
> > > > > > >
> > > > > > > I see there are a few HX-20 collectors on the net, they
> > > > > > > may be more informed.
> > > > > > >
> > > > > > > Kev
> > > > > > >
> > > > > > > >
> > > > > > > > I think I understand what you are saying. I'm sure they
> > > > > > > > are Masked ROMS or at least that would make sense. They
> > > > > > > > are a 4 chip chipset with numbers: EPSON BASIC1R0
> > > > > > > > M64020AA to M65023AA.
> > > > > > > >
> > > > > > > > The thing is however, that in identical machines, the
> > > > > > > > other EPROMS are 27C64 so the pinout would seem to have
> > > > > > > > to be the same or the EPROMS would not work right in the
> > > > > > > > other identical machines, would they?
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > >
> > > > >
> > >
> > >
>
Received on Sat Jun 22 09:46:14 2002