Re: ssm aio interface

[David Wilson <mcs6502@gmail.com>]

On Jan 31, 5:36 am, "Michael J. Mahon" <mjma...@aol.com> wrote:

> > it uses a 6550 uart i have found out cables from the asio board will
> > also work and these were also made by a company called transend
>
> That's good news.  I had completely forgotten about the 6550, which I
> assume has the same bit rate generator as the 6551.  If there are
> any differences in the control registers or behavior, then it may
> not work with ADTPro.

According to what I have found, the 6550 was a 1k x4 RAM chip - eBay
has some for sale as item # 250359789899. Does it perhaps have the
Motorola 6850? I know many 65xx parts are equivalent to 68xx eg 6820
and 6520 but I don't remember the 6550 being one.

The 6850 is a 24 pin ACIA with only 3 speeds selectable on chip - /1
(isosynchronous), /16 and /64 (asynchronous).