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I was playing around, again, with my Z80/8088/PropIO/4MB/PC-AT board set and
I still really can¹t get it working properly. I have gone over the boards
and I¹m pretty sure that there aren¹t any soldering issues. I¹ve also
re-flashed the ROMs just in case. Z80 version is 4.8. 8086 version is
10.33a. I will say that I¹ve never had a problem with the Z80 board in my
old configuration of a legacy 8-bit serial card and CompuPro 64k RAM board.

Here are some of the oddities I¹m seeing:
* When doing a memory map from the Z80, the ROM is shown as all ³p² except
for the xxFx address which is a ³.². For RAM, it does show ³R². It doesn¹t
matter where I locate the ROM. SoŠ
D000 R R R R R R R R R R R R R R R R
E000 p p p p p p p p p p p p p p p .
F000 R R R R R R R R R R R R R R R R
* In the 8086 monitor, if I use the ³R² command, it goes into lala land when
printing the flags, printing a continuous stream of ³0² after half of the
flags are printed
* In the 8086 monitor, if I use the ³A² memory map command, I get something
that looks like a map, but I get addresses like 00000,00000,80000,C0000 and
then each line is a mix of R and p. Finally it goes into lala land at the
end, continuously printing spaces.
* The RTC on the MSDOS board will not store the date/time and it returns
garbage when using the monitor commands which read them. I¹ve swapped the
chip and the battery is installed. As an example time ³25:06:00² and date
"20<7/26/14². It appears that the clock isn¹t running and can¹t be set.
I reduced the system to the PropIO, 4mb RAM and Z80 card so I could test the
RAM (at least the first 1mb) using a combination of the N and J commands. It
reported bad memory in each segment in the E000-EFFF range. This corresponds
to where my monitor resides in the first 64k, so maybe this is expected
behavior. No other memory errors were reported. I¹d have to say that the
first 1MB is probably OK

So that leaves the 8088 or MSDOS boards as being the problem. Since the
monitor anomalies occur without the MSDOS board, it has to be a problem with
the CPU card.

John, by chance do you have one of the 8086 cards for sale?  Maybe I¹ll
start from scratch using the 8086 card.

Rich

--
Rich Cini
Collector of Classic Computers
Build Master and lead engineer, Altair32 Emulator
http://www.classiccmp.org/cini
http://www.classiccmp.org/altair32


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