[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [N8VEM-S100:6409] Re: IMSAI 8080A CPU board help.


That is really really weird!  I am going to assume you are moving the Shadow ROM kill jumper right? And you have the 8212 chip for the output port installed (IC-J5)?

At this point, I would hook up the analyzer and watch the activity on the bus...   If you are in the neighborhood, you can drop by and we can swap chips to see if there's something intermittent about one of them?


Date: Sun, 22 Feb 2015 12:40:59 -0800
From: litte...@gmail.com
To: n8vem...@googlegroups.com
Subject: Re: [N8VEM-S100:6409] Re: IMSAI 8080A CPU board help.

Update !

With only the CPU board  <no prop i/o> I am able to boot/load the monitor and CP/M
using v1.2 firmware and related files.  I'm not familiar with the monitor syntax.  Is this
a common monitor program ? I'd like to know how to use it..  Otherwise I can load
CP/M and get the a> prompt. A "dir" command gives me one file MON-32K.COM.

Also, as mention in another thread, I was having an issue using v2.3 and a memory
error.  I did the test Josh had recommended to Jeff to test the lower RAM chip with the
command R 00 7F.  It took a bit but ran and passed.  I switched the two memory chips
and they all passed.

At this point I want to 'assume' my hardware is good, but my setup doesn't like v2.3 yet.

On Saturday, February 21, 2015 at 10:52:17 PM UTC-6, litterbox99 wrote:

I'm now using a comm port on the CPU board (w/HyperTerm & WinXP) & (The Console I/O) on the other.
They echo/mirror each other for key press & screen, but it still won't respond to anything but < R >
for the Ram test that fails @042A


----- Original Message -----
Todd, The firmware outputs to both the 8250 UART port 0 on board (I/O 20h) and to the Console I/O board at I/O 00h.
It will also accept any input from either console. If you connect them both, then you'll see a duplicate.
I was thinking of writing a seek and employee routine that would send messages to a range of I/O address and scan them all for a response ie, "Press <CR> to continue", but the variations were endless and such programming would take too much time. So I just hard coded support for the CONSOLE IO to the routines that already work with the on board uart.

Cheers, Josh

You received this message because you are subscribed to the Google Groups "N8VEM-S100" group.
To unsubscribe from this group and stop receiving emails from it, send an email to n8vem-s100+...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.