[comp.sys.ibm.pc] Baby Blue CoProc question

go@orstcs.cs.ORST.EDU (03/17/87)

[ Feed me Seymore! ]

I ran into a strange problem with the BREAK=ON command in config.sys.
Recently I obtained an old Baby Blue Z80 co-processor card for
the PC bus and thought it would be fun to bring it up.  (Microlog
is defunct now (I think), or I would ask them.)

After plugging in the board into my 4.77/8 Mhz Clone and making sure
that the clone speed was 4.77 Mhz (Baby Blue has Z80B -- max 6 Mhz)
I fired up the test program.  TESTZ80 says everything is fine.  Great,
ready to roll!.

I tried to run their sample "sample.cpm" after "binding" the emulator
file to it and, although it runs, it terminates with an MS-DOS
"internal stack error: system halted" message.  After much messing
and disassembling of programs later, I find that if I remove the
"BREAK=ON" line from my config.sys file, it runs and terminates fine.
Other Z80 CP/M programs seem to run fine now too.

Configuration:

	MS-DOS 3.2 (Yes, I know it has bugs...)
	640K main memory.
	8088-2 (standard "Turbo" clone)
	AST Six-pack with 1Meg "above board"
	Herc-compatible graphics at B000:0, etc.
	Baby Blue at E000:0 (their standard address)
	WD Disk controller+ST225

Turning off the drivers for the AST board and removing ANSY.SYS
doesn't change anything -- the only thing affecting operation is
the BREAK=ON.  Anyone have any ideas?  What strange things could
this rather simple-sounding command do?  The Baby Blue software
DOES NOT have any TSR's or fancy stuff that I can tell.

Mail to me -- this is probably too esoteric for the net.

Gary Oliver
...!hp-pcd!orstcs!go