Anybody use one of these SC131 CP/M systems

[alank2]

I just built one of these and this thing is really cool. I ended up with black case and white front/back panels. Everything needed came to run it I didn't need the serial cable/adapter so it cost me $66 + $8 shipping and came in 8 days from the UK to the US.

SC131 – Z180 Pocket Computer

SC131 is a pocket-sized Z180 RomWBW CP/M computer. SC131 – Description SC131 – Assembly Guide SC131 – Circuit Explained SC131 – Firmware, RomWBW SC131 – Firmware, SCM …

smallcomputercentral.wordpress.com

SC131 Pocket-sized Z180 RomWBW CP/M computer kit by Stephen C Cousins on Tindie

Pocket-sized retro computer in a small case running RomWBW CP/M

www.tindie.com

 

[durgadas311]

I went the SC203 with RC2014-bus route:

SC203 RCBus Modular Z180 Computer Kit by Stephen C Cousins on Tindie

Complete kit of parts to build a Z180 computer system designed for RC2014

www.tindie.com

But also got this very groovy ultra-mini:

MinZ-U - Z180 System at 33 or 36 MHz with 512 KB by Circle M Systems on Tindie

Z180 System at 33.333 MHz or 36.864 MHz with 512KB RAM and USB for power and serial ports

www.tindie.com

Did work on these to run "CP/M" with only a serial port (no local disks), by booting them into CP/NOS (CP/NET "Network Only System" - diskless). The MinZ-U provides full handshake on the second serial port, so in that case I could run CP/NET and the console separately. For the SC203 (proof of concept for running CP/M on a CPU, 64K RAM, one serial-port) used a special CP/NET server mode and multiplexed console and CP/NET traffic over a single serial port.

 

[alank2]

The kit was great; it had everything needed except solder.

That MinZ is cute!

 

[durgadas311]

Yes, Steve Cousins does great work.

 

[kurt_kayger]

Hi,
where can I find the adapted cp/net version?

greeting
Kurt

For the SC203 (proof of concept for running CP/M on a CPU, 64K RAM, one serial port) used a special CP/NET server mode and multiplexed console and CP/NET traffic over a single serial port.

 

[durgadas311]

As I was just doing a POC, I didn't really make a formal product out of it. The server part is released at https://github.com/durgadas311/cpnet-z80 specifically https://github.com/durgadas311/cpnet-z80/blob/master/contrib/CpnetSerialServer.jar and documentation https://github.com/durgadas311/cpnet-z80/blob/master/doc/CpnetSerialServer.pdf (look for "Console Mode" for details on this particular use case, and properties named "cpnet_console_*").

The client side, however, is in https://github.com/durgadas311/minimalCPM which is not made into a general-purpose product.

Let me know your particular hardware and ROM, and I can try and put together what you need. If you are running CP/M on local ramdisk/romdisk, it is a different setup than if you need to boot directly from ROM into CP/NOS.

 

[kurt_kayger]

Hi, thanks for the offer.
I use the SC126.

Kurt

 

[durgadas311]

Hi, thanks for the offer.
I use the SC126.

Kurt

OK, but are you running any additional hardware like local disk storage? Are you using RomWBW or SCM? Are you booting into CP/M or do you need to network boot directly from ROM?

There are some cases where it becomes difficult or impossible to use CP/NET over the console serial port, such as RomWBW versions of CP/M where the console port is under total control of RomWBW. For my experiment, I created my own, minimal, ROM code that boots over the console (neither SCM nor RomWBW). I did add a network boot command to RomWBW (not sure if that's in your version), but it uses the WizNET Ethernet module, not serial port. I have a "network loader" program that runs under CP/M (and layers CP/NET on top), but that has problems with RomWBW taking over the console port.

The second serial port doesn't work well for CP/NET because it has no handshake lines for flow-control, at least on these systems (the MinZ-U added CTS to the second serial port).

Do you have the capability to burn your own ROMs? Or do you have methods that you've used to download programs into your system? We'd need a way to get the right code onto your system, either by adding it to existing CP/M images or changing the ROM code.