ASCI u68 (SystemX)
scaron at umich.edu
Fri Oct 16 13:34:55 CDT 2015
There has to be some support for it in the ROM ... otherwise it won't do
anything ... and may in fact cause the system to behave strangely (having
an uninitialized ACIA just sitting there on the bus) ... I'm fairly new at
writing assembly code but I found it was a few hundred lines of code to
implement a simple little monitor that could read strings from a serial
line and echo them back (on 6502, for comparison's sake). I guess since
this is a pre-built board, not something you made from scratch, this may
have already been done for you :O If the board looks OK ... no shorts, etc
... might as well power it up with a tty and see what happens! Assuming
there is an ACIA on board and it's wired to that port ...
On Fri, Oct 16, 2015 at 2:27 PM, Brad <unclefalter at yahoo.ca> wrote:
> Many thanks. I'll take a quick look online just to see if I can save you
> the trouble. I'm surprised at how little documentation there is for this
> As a general rule, does anyone know -- if you have a single board computer
> like this with serial connector, is that 'live' all the time? Or do you
> usually have to invoke a program in order for a terminal to connect to it
> and use it?
> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of
> drlegendre .
> Sent: Friday, October 16, 2015 11:06 AM
> To: General Discussion: On-Topic and Off-Topic Posts <
> cctalk at classiccmp.org>
> Subject: Re: ASCI u68 (SystemX)
> The Heathkit ET-3400 (another SBC trainer) also used the M6800 CPU. Now I
> realize that the two machines probably have fairly different ROMs, but
> otherwise some of the 3400 materials / programs should cross-over to the
> u68. It might even simply be a matter of translating ROM calls..
> Anyway, I have a full set of docs for the ET-3400. If you're interested, I
> can find a way to get a copy to you.
> On Fri, Oct 16, 2015 at 11:16 AM, Brad <unclefalter at yahoo.ca> wrote:
> > Hey guys,
> > Posting this to various forums in the hopes of finding someone in the
> > know
> > -
> > I have this ASCI u68 system (6800 cpu) that I understand was used in
> > educational environments. I kind of have it running but know little
> > about assembly language programming, etc. Or the unit itself. Have
> > any of you ever messed with these? It looks like it has a serial
> > connector on its mainboard.. was trying to figure out a way if I could
> > patch it to one of my terminals.
> > Also trying to find some simple 6800 assembly programs/routines to
> > test it and see if it really works properly. There is an MC6821S chip
> > on it (there are three of them actually) and one in the middle is
> > marked 'BAD'. I understand those handle peripherals.
> > I'd also heard rumours there was a second board available for these
> > that gave them BASIC. I've never seen such a board for sale anywhere
> > - wondered if anyone had seen one in the wild.
> > Brad
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