Re: Working Commodore LCD emulator & specification is available now

From: Gábor Lénárt <>
Date: Wed, 29 Jan 2014 11:58:18 +0100
Message-ID: <>

On Wed, Jan 29, 2014 at 09:40:02PM +1100, Daniel O'Shea wrote:
> On 22/01/14 02:16, Gábor Lénárt wrote:
> >Now after about a month of work, I have my own more-or-less working
> >Commodore LCD emulator (currently written in JavaScript) and some kind of
> >specification I managed to collect or find out myself, etc etc. Of course
> >the emulator itself is far from being really good, but still it's a start.
> Decided to investigate the non-working MAME / MESS Commodore LCD
> emulator that you mention on your site, and it looks like there has
> been a considerable amount of work done on it since the last
> official MAME build:
> Mostly as recent as this last week! I downloaded / compiled the
> latest source and the Commodore LCD emulator is now working very
> nicely... apart from the available ROM files it also requires an
> lcd_char_rom file, found the file here:

It's possible. More people (so, more than one) sent me private mails about
the mame/mess (with its LCD emulation in a "non-working-yet" state), and I
tried to help them.  Probably this caused the progess you could notice in
the previous weeks :)

As far as I know, there is no "official" character ROM image for the
Commodore LCD yet on the net.  What I used in my emulator is a dirty trick:
as I've found some kind of (upper case only) charset in the kernal ROM image
(I guess it was not the one used by the LCD controller though, but for other
purpose like rendering characters in gfx mode, or whatever - as the LCD
controller use character ROM which is not accessible by the CPU - as far as
I know, again), I've patched that to form the alternate charset (relocating
upper case chars) and use some random internet resource with 6*8 lower case
characters.  Probably that file is like this, at least I also had discussion
about the method in private mails (and I also documented the method that on
my site). I am not sure though.

The best would be to have to original charset ROM, no doubts. As far as I
know Mike Naberezny is again on the project to get that, in addition to his
nice move in the past to get the ROM images I use now in my emulator too :-D
Thanks for that, and I'm especially sorry that I forgot to mention his name
on my pages on the start, it seems I missed the story of the ROM images, or
at least forget (because the story itself felt familiar after we had some
discussion on the topic with Mike - and the "best": I have even linked his
blog without noticing that I should drop a thanks to him as well). 
Hopefully nobody thought too much that I want to keep not to give credits to
him by intent. Hopfully this issue has been resolved for now, and no bad
feelings left.

I would have loved to help mame/mess project on the CLCD emulation directly,
but after getting the info it's mostly C++ I gave up (I hate C++, impossible
to learn for me because of some unknown reason, I've tried multiple times
during the years - surely it's me, not the language ...).  So at least I try
to help indirectly, of course.

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Received on 2014-01-29 11:01:05

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