[comp.os.cpm] Need help with brain-damaged bdos.

simon@ms.uky.edu (George Simon) (07/12/88)

Help!!!
	I have a z80 cpm box at work that has problems, and I'm looking
	for ideas to improve it a little.  If it were up to me, I'd
	replace it with a Pc, but for several reasons, we need to continue
	to use it.

	The version of cpm that it is running seems to be < 2.2, and 
	the bdos seem to be brain-damaged.
	(1) There is no escape code to position the cursor, however 
		calling the bios CONOUT routine to print a 0x18 with the 
		row/col in HL does the job.  (don't even ask how I found
		this out!)
	(2) Bdos function 6 (direct console i/o) does not exist, but 
		the corresponding bios calls work ok.  Other bdos calls 
		may be ok, but I trust the bios much more.  The bdos also
		refuses to return the version#.
	
	The computer itself is a Videoplan form Kontron Electronics 
	(in Munich & California), has 1 Z80-sio, 1 ctc, 2 pio's (keyboard 
	& printer) and a WD1771-B01 floppy controller (single density). 
	The motherboard is a (4mhz?) KDT rev. IV.  If anyone from Kontron 
	is reading this, and has any docs on this board, please send me 
	e-mail.

	Even its disks are strange - single density, 35 tracks x 2 sides, 
	and 16 sectors/track yielding about 138K per disk.

	I've been thinking about getting Z-cpr to replace the bdos/ccp,
	but I'm not sure if it would even install in such a brain damaged
	system.  I have no hardware or software docs on this machine, but
	I have found all of the port#s for the sio/ctc/pio's, and can
	probably find the floppy controller and video (Motorola 6845L) if
	needed.  

	Anyone got any other ideas?  I'd love to be able to do double-density,
	but I don't know if the WD1771 can do this.  I have heard that 
	Z-Cpr 3.4 is self-installing, but it may have problems here...
	I have managed to get kermit running, but I'd like to get turbo
	pascal or a c-compiler working.  Respond via e-mail, or post it
	if you think others would be interested.
							Thanks in advance,
								Simon.

<-------------------------------------------------------------------------->
<---   Simon Gales@University of Ky 	     (606) 257-3597/254-9387 	--->
<---            [ simon@ms.uky.edu ]  |  [ simon@UKMA.BITNET ]          --->
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mwilson@crash.cts.com (Marc Wilson) (07/13/88)

In article <9936@e.ms.uky.edu> simon@ms.uky.edu (Simon Gales) writes:
>Help!!!
>	I have a z80 cpm box at work that has problems, and I'm looking
>	for ideas to improve it a lit
>
>	The version of cpm that it is running seems to be < 2.2, and 
>	the bdos seem to be brain-damaged.
>	(1) There is no escape code to position the cursor, however 
>		calling the bios CONOUT routine to print a 0x18 with the 
>		row/col in HL does the job.  (don't even ask how I found
>		this out!)
>	(2) Bdos function 6 (direct console i/o) does not exist, but 
>		the corresponding bios calls work ok.  Other bdos calls 
>		may be ok, but I trust the bios much more.  The bdos also
>		refuses to return the version#.

     What you are describing sounds very much like CP/M 1.4.  It implemented
neither the BDOS 6 call, nor the BDOS 12 call ( well, it *did* do BDOS 12,
but it used it for something else ).

     As for trusting the BIOS, watch out.  There are differences between the
2.2 BIOS and a 1.4 BIOS.

>	The computer itself is a Videoplan form Kontron Electronics 
>	(in Munich & California), has 1 Z80-sio, 1 ctc, 2 pio's (keyboard 
>	& printer) and a WD1771-B01 floppy controller (single density). 
>	The motherboard is a (4mhz?) KDT rev. IV.  If anyone from Kontron 
>	is reading this, and has any docs on this board, please send me 
>	e-mail.
>
>	I've been thinking about getting Z-cpr to replace the bdos/ccp,
>	but I'm not sure if it would even install in such a brain damaged
>	system.

     I can almost guarantee that you won't be able to install the Z-System
on this machine.  You need a 2.2 system for that.  NZCOM will probably
blow up if you try to use it.  Save your money.

>
>	Anyone got any other ideas?  I'd love to be able to do double-density,
>	but I don't know if the WD1771 can do this.

     I know that the 1770 can, but it needs external help.  How do I know
this?  This computer right here ( Ampro LB/Z80 ) uses the 1770.  Pick
up the data sheets on the chip from Western Digital.  They've always been
most helpful when I've spoken to them.

     Good luck!

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Marc Wilson
     ARPA: ...!crash!mwilson@nosc.mil
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     INET: mwilson@crash.CTS.COM
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

dg@lakart.UUCP (David Goodenough) (07/27/88)

From article <9936@e.ms.uky.edu>, by simon@ms.uky.edu (George Simon):
> Help!!!
> 	The version of cpm that it is running seems to be < 2.2, and 
> 	the bdos seem to be brain-damaged.
>
> 	(2) Bdos function 6 (direct console i/o) does not exist, but 
> 		the corresponding bios calls work ok.  Other bdos calls 
> 		may be ok, but I trust the bios much more.  The bdos also
							    ^^^^^^^^^^^^^
> 		refuses to return the version#.
		^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This may be part of your problem: function 12 (0xc) in V2.0 and higher
gives back the version number - V1.X does not: it appears that you have
a very early version. To verify this try some tests of the random access
routines: if they fail you almost certainly have a pre 2.0 bdos.
 	
> 	Anyone got any other ideas?  I'd love to be able to do double-density,
> 	but I don't know if the WD1771 can do this.  I have heard that 

Sadly the 1771 only talks single density, and I don't know if the 1791 /
1793 would be a dropin replacement.
-- 
	dg@lakart.UUCP - David Goodenough		+---+
							| +-+-+
	....... !harvard!cca!lakart!dg			+-+-+ |
						  	  +---+

mlinar@eve.usc.edu (Mitch Mlinar) (07/29/88)

In article <187@lakart.UUCP> dg@lakart.UUCP (David Goodenough) writes:
#From article <9936@e.ms.uky.edu#, by simon@ms.uky.edu (George Simon):
## 	The version of cpm that it is running seems to be < 2.2, and 
## 	the bdos seem to be brain-damaged.
##
## 	(2) Bdos function 6 (direct console i/o) does not exist, but 
## 		the corresponding bios calls work ok.  Other bdos calls 
## 		may be ok, but I trust the bios much more.  The bdos also
## 		refuses to return the version#.
#		^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
#
#This may be part of your problem: function 12 (0xc) in V2.0 and higher
#gives back the version number - V1.X does not: it appears that you have

True, but still usable as is.  In CP/M 1.3 and 1.4, it was not *intended* to
return the version number, but rather some obscure disk function like "unload
heads" or something like that.  The function *is* supposed to return A=00,
which lets you know it is earlier than CP/M 2.x or MP/M.

# ## 	Anyone got any other ideas?  I'd love to be able to do double-density,
# ## 	but I don't know if the WD1771 can do this.  I have heard that
#Sadly the 1771 only talks single density, and Idon't know if the 1791 /
#1793 would be a dropin replacement.

David is correct about the single-density 1771; also, the 1791/1793 is NOT a
drop in replacement.  You need a bit of external clock/data separation
circuitry to run double density as well as a higher clock rate to the chip
itself (2 MHz instead of 1 MHz).  Potentially some major board work here...

I missed out on the earlier conversation, so don't know what system you have
and if there is some adapter kit sold for your machine.

-Mitch