I am using the 1.0.005, POST runs correctly,
reports the correct clock rate and the correct SRAM size, it
just seems to not want to write to NVRAM and there is no
activity from the floppy, it also reports no boot disk. I
was hoping that it would be something simple like an
incompatible chip, but, I guess I have a hardware problem to
debug!
Thanks!
Dan
Dan,
The 80188 and 80C188 are slightly different chips. The
80C188XL, I am pretty sure is compatible with the AMD
N80C188-25 chip that Andrew distributes. I have also tested
the Intel N80C188, no suffix. It is a lower clock rate. The
design speed of the board was 16Mhz (32Mhz oscillator);
without the 4MEM board, the lone board has been run by both
Sergey and me at 25Mhz (50Mhz oscillator).
The board revisions are printed on the SBC-188 CPU board:
00.4 -- the earliest -- needs several updates
(Update-2010-10-25.txt)
1.0.005 -- the version 1.0 board -- has all the
revisions
The 00.4 is printed near pins A32,B32,C32 of the ECB
connector.
The "rev 1.0.005" is printed in the middle of the board.
The 00.4 board can be updated to 1.0.005 by installing all of
the h/w mods, including adding a chip to the FDC logic.
Jumper settings may also affect proper operation of the
board. J8 (1-2) is the critical one. The schematic has a
table of jumper settings for the various size and type of ROM
chips.
BIOS037 does a P.O.S.T. (power on self test) of memory when it
starts. It should correctly report the size of the SRAM chip
you are using. It should also report the CPU clock rate
accurately.
--John
On 07/09/2011 09:45 PM, Dan Werner wrote:
Now that the pace at work is slowing down to a "normal" level, I am
trying to get caught up with the current state of all of the
boards. While I am focusing on 6802 FLEX, I am currently waiting on
parts, so I decided to get my SBC-188 working. It does appear to be
working somewhat, but it has some sort of IO problem (no floppy
activity of any kind, and it does not seem to be storing the NVRAM
correctly).
So I thought I would start by making sure that the 80c188XL-20 chip
that I am using is compatible, and to ask which chip others are
using? I am using BIOS37 and the V1 board.
Thanks!
Dan Werner
--
You received this message because you are subscribed to the
Google Groups "N8VEM" group.
To post to this group, send email to n8...@googlegroups.com.
To unsubscribe from this group, send email to n8vem+un...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/n8vem?hl=en.
--