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MP/M & CP/NET [message #9394] Sun, 21 November 2021 04:15 Go to next message
tapy is currently offline  tapy
Messages: 17
Registered: June 2021
Junior Member
Hi all,
I would like to present my challenge I set myself to celebrate the 40th anniversary of MP/M II and CP/NET release. To realize my idea I used popular RC2014 kits, as a CP/NET network server I used Z180 computer working under MP/M, while the client stations are typical Z80 kits. On the client side CP/NET was loaded from CP/M v2.2 and on diskless computers with CP/NOS. As a network controller I used COM20020 working in Arcnet standard, in the physical layer RS485 driver - SN75176. The use of this archaic standard was dictated by the desire to preserve the "spirit of the times" so as not to use contemporary solutions using microcontrollers superior in performance to the entire network to support the TCP/IP stack and Ethernet. At the moment the whole thing is up and running, but I still need to add code to support frames longer than 252 bytes. I'm not entirely satisfied with the results as I had to give up using interrupts for incoming packets as MP/M randomly crashed during heavy disk usage by requesters. It is possible that this is due to my misunderstanding of the operation of the rather peculiarly programmed Arcnet controller, or that MP/M quite often disables the interrupt system during its operation. I will continue to work on this problem, as using interrupts is more "elegant" than using polling for incoming packets. I think I'll get this project out to the community by this anniversary.

Tadeusz Pycio

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Re: MP/M & CP/NET [message #9395 is a reply to message #9394] Sun, 21 November 2021 08:29 Go to previous messageGo to next message
just4fun is currently offline  just4fun
Messages: 273
Registered: May 2017
Location: Dark side of the Moon
Senior Member
Interesting...
Re: MP/M & CP/NET [message #9397 is a reply to message #9395] Sun, 21 November 2021 08:52 Go to previous messageGo to next message
tapy is currently offline  tapy
Messages: 17
Registered: June 2021
Junior Member
Here is a short video showing network disk and file operations under MP/M. The top half is two MP/M consoles, the bottom left is CP/NET running under CP/M, and the right is a diskless station with CP/NOS. Sorry for the quality, the video should be viewed on screens over 20", but I don't feel like becoming a youtuber. Ultimately, as a CP/NET server, the MP/M system will support a single console.
Re: MP/M & CP/NET [message #9410 is a reply to message #9397] Tue, 23 November 2021 15:45 Go to previous messageGo to next message
tingo is currently offline  tingo
Messages: 114
Registered: February 2017
Location: Oslo, Norway
Senior Member
Nice! Thanks for doing this and making the video. Very interesting.

Torfinn
Re: MP/M & CP/NET [message #9451 is a reply to message #9410] Sat, 04 December 2021 08:15 Go to previous messageGo to next message
tapy is currently offline  tapy
Messages: 17
Registered: June 2021
Junior Member
I've made MP/M for Z180 available, I'll try to make all CP/NET available in the near future, the network card has been already here for some time. I have been interested in the CP/NET development of Douglas Miller and would like to give it some attention, so there may be a slight delay.
Re: MP/M & CP/NET [message #9453 is a reply to message #9451] Sat, 04 December 2021 11:21 Go to previous message
wsm is currently offline  wsm
Messages: 232
Registered: February 2017
Location: AB, Canada
Senior Member
FYI: If you're trying to get Doug's CP/NET working and need a simple Z180 board, he has one of my MinZ-U boards which he has up and running via serial over USB. They're available <here>.
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