On Wed, May 6, 2009 at 4:29 PM, Nicolas Welte <no_spam@x1541.de> wrote:
> Hi,
>
>> What's the story on the fancy Welte board? Is it still available, either
>> built or PCB and logic?
>
> The 6540 and 6550 adaptors are available as PCB only or DIY kit with all parts. But they work only in the video part of a 2001 board, because they don't decode the chipselect lines. In the video circuit, RAM and ROM are always enabled.

Now that I'm home, I went through my bin of surplus C= dealer chips
(15 years ago I bought the entire service department of a dealer that
was closing) and unfortunately did *not* find the parts I'd hoped to
find.  I have a few original PET BASIC and Kernel ROMs, but no video
SRAMs.  It looks like I'll have to consider a set of those boards.  I
wish I'd known a couple of years ago when I made my last PETRAM order.

> I have the universal 6502 RAM/ROM expansion board (aka PETRAM) which goes into the 6502 socket of a 2001 PET, and it can be used to replace all 6540 ROM and 6550 RAM. Unfortunately, I am out of stock with this PCB, and my next reorder depends on my completion of another unfinished project, so I can get better prices for the PCBs by bundling the PCB order.

I already have three PETRAM boards, so I doubt I'll be placing an
order soon, but I still have enough PET gear that I can see wanting
another PETRAM or two down the line.

I wish I hadn't sold my intact 8K PET - it had bad socket disease with
the main memory sockets - something the PETRAM is perfect for.

-ethan


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