[sebhc] Trying to get NetPC 3.4 running ...

Dwight K. Elvey dwight.elvey at amd.com
Mon May 3 11:18:13 CDT 2004

>From: "Scott LaBombard" <labomb at rochester.rr.com>
>Too many mailing lists ... too little time ... sorry folks. I posted
>this to the wrong list ... Jack asked me to leave it for a couple
>of reasons ...read on:
>I've been giving some thought as to the possibility of having
>an equivalent to NetPC for the H8. For those of you who may
>not know what NetPC is ... it essentially allows access from
>a Swtp system to disk images that reside on a PC. The access
>is done in such a way so as to make the images appear as real
>disks to the Swtp (running Flex as the operating system). The
>approach is implemented over a serial port ...a piece of code
>runs on both ends of the connection.
>It would seem that there would be a way to take advantage of
>the H8 simulation work that has been available for some time
>to implement a NetPC capability for H8. Specifically, we should
>be able to use a stripped down iteration of the simulator to handle
>the disk image IO. Instead of having a full simulator that accepts
>disk related commands from the console (and that has a full GUI),
>it would accept disk related commands via the serial port (sent
>from the H8 while booted in HDOS, or perhaps even CP/M).
>I know that Dwight and others have done some work in this
>area ... any comments?

 I'm not at all familiar with the NetPC 3.4 methods. I do
understand the concepts. For the most part, access to disk
routines is through the jump tables but some software also
look at some of the system variables to understand various
disk status.
 The stuff I wrote was just specifically to transfer images
and to allow one to bootstrap a machine without having
anything other than a serial cable, blank disk and a PC.
 Still I don't believe that any of the applications talk
directly to the 8250 or 179? chips used for disk interface.
This means that almost any kind of software emulation could
be done. Using the parallel port is always possible. I made
my own parallel printer port for my H89 and added my own
driver. The serial port is still the most common port used.
It may not be the fastest but it is the most universally
 As for returning values from unknown ports, the value
0 it the least likely. For machines with Z80's one would
expect one of two values to be returned. It would either
be an echo of the port address for an unterminated bus
or $0FF for most terminated or with standard TTL type

>----- Original Message ----- 
>From: "Scott LaBombard" <labomb at rochester.rr.com>
>To: <sebhc at sebhc.org>
>Sent: Sunday, May 02, 2004 12:01 PM
>Subject: [sebhc] Trying to get NetPC 3.4 running ...
>> Hi folks,
>> As the subject indicates ... I've been attempting to get NetPC 3.4 up
>> and running on a recently restored Swtp S/09 system. NetPC starts
>> up and displays the 'NetPC driver version 3.4' banner ... and then it
>> sits for a minute or so (presumably trying to connect) and then times
>> out with 'Can't sync serial transfer!'.
>> Here are the system specifics (intentionally verbose):
>> * The S/09 has an MP-09A that is configured for extended addressing
>> and SBUG 1.8. The system is currently configured to run at 1mhz.
>> * Installed boards include the MP-ID board, an MP-S2 with only a
>> single port installed on IO port 0 (console), an MP-S2 with both ports
>> installed on IO port 1, and two MP-L2 dual port parallel boards
>> installed on IO ports 2 and 3. In addition, there is a DMAF2 disk
>> controller, connected to the Swtp dual 8" drive cabinet. For memory,
>> it has the Swtp SMS3509 memory system (with the SMS3509C
>> controller card, and one SMS3509A 128k memory array card).
>> * The operating system is Swtp's flavor of Flex, version 2.7:3.
>> * The PC side is a Thinkpad laptop with DOS 6.3 installed. I use
>> this system as a 'console' (running term emulation) for most all of
>> my vintage systems. I'm using a standard DB9-DB25 serial cable.
>> I'm connecting the PC to the dual MP-S2 at IO port 1. I've
>> modified acia.txt to use port A on the MP-S2:
>> aciac equ $E010
>> aciad equ $E011
>> I've also tried $E014,$E015 with the PC connected to port B. I've
>> also tried adding the 6850 uart initialization code to acia.txt (even
>> though it is in netdrv.txt already). Last, I also tried just using a three
>> wire connection (pins 2,3, and 7) ...all with no luck.
>> The dual MP-S2 has been verified functional installed at IO slot 0
>> and connected to a console.
>> The config.txt file on the PC side is set for 9600 baud, the MP-S2
>> is configured for 9600 baud (strapped). Debug is on in config.txt...
>> no messages are generated when I run netdrv.bin on the S/09. I've
>> tried both 'slow' and 'fast' configurations. NetPC initializes just fine
>> on the PC.
>> Also, netdrv.txt was assembled on the S/09 itself using asmb.cmd.
>> No assembly errors were generated.
>> I imagine that I'm missing something simple here ... any suggestions
>> would be most welcome. Thanks ...
>> Regards,
>> Scott
>> --
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