New to RC2014.....

215 views
Skip to first unread message

Michelle Lawson

unread,
Nov 6, 2025, 4:40:07 PMNov 6
to RC2014-Z80
.... but not to the Z-80 world. My first Z-80 was back in the late 70s, and I have a couple sitting around the house that I still use. That said, the RC2014 system looks interesting. I've been lurking about looking at some of the products, and trying to figure out the best way to start dabbling.... So, I kinda came up with a wish list of sorts...

1. A standard bus config should be enough for what I want to do
2. A Z-80 CPU card with an onboard clock (saw one on Tindie)
3. 64K should be plenty for what I have planned, assuming I can find a way to make the first 8K take ROM.
4. A serial card that uses the 85C30 dual UART. I already have a few of those, and pretty familiar with the code they require
5. A printer interface would be of use as well
6. As would a card to take a CF Card or similar IDE type device

All I can think of at the moment, but hey, it's a buss, so always able to take more goodies.... Hugs

Alan Cox

unread,
Nov 6, 2025, 5:59:34 PMNov 6
to rc201...@googlegroups.com
Yep you end up then needing a bus extender to get 15+ slots 8)

Of your hardware all of it exists off the shelf except I think the 85C30 as the current multiport serial are either Z80SIO, 16x50, or a mix of 2691 derived parts. 

The 512K RAM/ROM will let you put 16K ROM anywhere you want and RAM banks similarly on 16K boundaries. The standard ROM and RAM setup gives you 8K (configurable) actually ROM that can be paged out and RAM that fills the rest of the 64K.

There's a 3rd party RC2014 printer port that's good enough to run things like ZIP drives as well as printers.

Tadeusz Pycio

unread,
Nov 6, 2025, 6:13:06 PMNov 6
to RC2014-Z80
85C30 SCC modules are also available, but in the form of Gerber files and for the more advanced RCBus bus. The presented model can use IM2 interrupts.

scc22.jpg

Michelle Lawson

unread,
Nov 6, 2025, 6:16:55 PMNov 6
to RC2014-Z80
Yep, I was not able to find any boards to support the 85C30, but this looks very promising. Where might one go to find more out on this board?

Tadeusz Pycio

unread,
Nov 6, 2025, 6:30:30 PMNov 6
to RC2014-Z80
The creation process is described here, and I will endeavour to upload the production files to my Github in the near future.

Michelle Lawson

unread,
Nov 6, 2025, 7:12:43 PMNov 6
to RC2014-Z80
Well, I think I have a good start to a base system. Once I get an idea about the serial card Tadeusz is developing, I think this will work out great. So, please take a look at my lineup and feel free to point out anything I have overlooked. Looks like I'll be ordering stuff soon I suspect. I do need to hunt down a couple of protoboards that have a 'pad-per-hole' config though, and any other cool things that might be worth adding.

SC141 Modular Backplane Kit for RC2014/RCBus-40pin
https://www.tindie.com/products/tindiescx/sc141-modular-backplane-kit-for-rc2014rcbus-40pin/

SC601 Z80 CPU Module Kit for RC2014/RCBus-40pin
https://www.tindie.com/products/tindiescx/sc601-z80-cpu-module-kit-for-rc2014rcbus-40pin/

SC606 Real Time Clock Kit for RC2014/RCBus-40pin
https://www.tindie.com/products/tindiescx/sc606-real-time-clock-kit-for-rc2014rcbus-40pin/

64k RAM Module
https://z80kits.com/shop/64k-ram-module/

SC145 Compact Flash Kit for RC2014/RCBus-40pin
https://www.tindie.com/products/tindiescx/sc145-compact-flash-kit-for-rc2014rcbus-40pin/

MG014 Parallel Port Interface- Designed for RC2014
https://www.tindie.com/products/mrgelee/mg014-parallel-port-interface-designed-for-rc2014/

Tadeusz Pycio

unread,
Nov 7, 2025, 2:09:29 AMNov 7
to RC2014-Z80
The set presented is incomplete; the ROM module is missing. Personally, I would choose a backplane with 80-pin slots, e.g. SC709 or SC710, which offer greater development possibilities and ensure full compatibility with 40-pin modules.

Fernando Carolo

unread,
Nov 7, 2025, 3:36:45 AMNov 7
to rc201...@googlegroups.com
Another small suggestion, Michelle: the SC145 is based on an older design and is known to have issues with some CF cards.

Steve Cousins has two newer modules based on a design from Tadeusz Pycio that fixes the timing issues between the Z80 bus and the cards, the SC604 (for the standard RC2014 bus) and the SC729 (for the 80-pin RCBus). I strongly recommend getting one of the new designs.


On Fri, Nov 7, 2025 at 7:09 AM Tadeusz Pycio <ta...@wp.pl> wrote:
The set presented is incomplete; the ROM module is missing. Personally, I would choose a backplane with 80-pin slots, e.g. SC709 or SC710, which offer greater development possibilities and ensure full compatibility with 40-pin modules.

--
You received this message because you are subscribed to the Google Groups "RC2014-Z80" group.
To unsubscribe from this group and stop receiving emails from it, send an email to rc2014-z80+...@googlegroups.com.
To view this discussion, visit https://groups.google.com/d/msgid/rc2014-z80/69d4bb78-ce30-4e39-b5f3-e5b6f3919a8cn%40googlegroups.com.

Michelle Lawson

unread,
Nov 7, 2025, 6:35:49 AMNov 7
to RC2014-Z80
Thank you all. I have updated my config to use the SC709 & SC729. But, if changing to the 80 pin motherboard, should I consider any other changes to the other cards to be 80 pin as well? As to the question of a ROM board, I had planned on using NVRAM devices instead of actual SRAM chips. That should work fine I'd think for my initial thought of building this system as sort of an appliance with a specific use. But; thinking cap on now, what if I wanted to run CP/M 2.2 on it, and have my 'appliance' code just be a CP/M 2.2 program? That would work too and then begs the question; what would need to change in my configuration to support booting and running CP/M 2.2?

Wayne Warthen

unread,
Nov 7, 2025, 11:31:13 AMNov 7
to RC2014-Z80
On Friday, November 7, 2025 at 3:35:49 AM UTC-8 Michelle Lawson wrote:
As to the question of a ROM board, I had planned on using NVRAM devices instead of actual SRAM chips.

I don't think NVRAM would supplant the need for a ROM board.  There are only 32 bytes of NVRAM and it is not usable for bootstrapping.

Thanks, Wayne

Michelle Lawson

unread,
Nov 7, 2025, 11:58:24 AMNov 7
to RC2014-Z80
Ahh, I have 32Kx8 NVRAM in another project ( M48Z35-70PC1 ) that works great as part of a RAMdisk I use on another CP/M 2.2 machine I have. But, at the same time, I am starting to gravitate to having the RC2014 machine I want to put together, run with CP/M 2.2 as well. So, I guess I will tweak some things so I can run that OS. Thanks

Wayne Warthen

unread,
Nov 7, 2025, 12:07:38 PMNov 7
to RC2014-Z80
On Friday, November 7, 2025 at 8:58:24 AM UTC-8 Michelle Lawson wrote:
Ahh, I have 32Kx8 NVRAM in another project ( M48Z35-70PC1 ) that works great as part of a RAMdisk I use on another CP/M 2.2 machine I have.

My mistake.  I was assuming you were referring to the NVRAM found in the standard RC2014 RTC board.  Now that I say it, I realize you didn't have that board included on your list.

-Wayne

Michelle Lawson

unread,
Nov 7, 2025, 12:28:19 PMNov 7
to RC2014-Z80
I do have this RTC board listed though:
Michelle

Steve Cousins

unread,
Nov 7, 2025, 2:35:23 PMNov 7
to RC2014-Z80
I'd suggest starting with a full set of known working modules and supporting software/firmware. This would allow you to get an initial system up and running without the unknowns of unproven hardware and software. Once you have a functioning system it will be easier to add new module designs, both the hardware and its support software.

With that in mind I think a 68B50 ACIA serial module or a Z80 SIO/2 serial module would be a good addition to your list. Standard RC2014 compatible firmware and software is available for both of these options. You would also need a means of adding standard RC2014 compatible firmware. ie. a ROM module compatible with your chosen RAM module, or a module containing both RAM and ROM.

I do have a very basic 85C30 serial driver in SCM but it is not included in the RC2014 builds.

Steve

Wayne Warthen

unread,
Nov 7, 2025, 2:40:03 PMNov 7
to RC2014-Z80
On Friday, November 7, 2025 at 11:35:23 AM UTC-8 Steve Cousins wrote:
I do have a very basic 85C30 serial driver in SCM but it is not included in the RC2014 builds.

A SCC (8530) driver was just added to RomWBW development snapshots.  It is currently only enabled for S100 systems where I had an 8530 to test with.  But the driver should be OK for other systems with just config changes. 

Thanks, Wayne

Michelle Lawson

unread,
Nov 7, 2025, 3:34:38 PMNov 7
to RC2014-Z80
Well, first, thank you all for all your help. It's looks like I'll be getting most of the hardware from 'Steve's House of Fine Computers'..... From what I have gathered from you all, how does this updated System BOM look for running CP/M 2.2? I can use the ACIA interface for the console/terminal and add the 85C30 boards at a later date as they will be used with code I write to run under CP/M...

From what I have been reading, I 'think' these are compatible. Hopefully I get this noodled out in time to put under the tree.... Thanks

Spencer Owen

unread,
Nov 7, 2025, 3:48:18 PMNov 7
to rc201...@googlegroups.com

I know I am coming in a bit late on this, but as Steve says, going for a complete set of known compatible boards is a good base for developing your own hardware or software.

Obviously I am biassed, but as you were asking about RC2014 kits, I would suggest the RC2014 Pro (https://z80kits.com/shop/rc2014-pro/) or maybe the RC2014 Zed (https://z80kits.com/shop/rc2014-zed/). Apart from the parallel port I think these tick your boxes.

Spencer

--
You received this message because you are subscribed to the Google Groups "RC2014-Z80" group.
To unsubscribe from this group and stop receiving emails from it, send an email to rc2014-z80+...@googlegroups.com.

Steve Cousins

unread,
Nov 7, 2025, 6:08:06 PMNov 7
to RC2014-Z80
Michelle, your latest list would make a working system and everything should be compatible.

However, I think there are substitutions worth considering.

I think I'd select SC602 instead of SC714. SC602 has two Flash ROMs selectable with a switch. Typically, one contains RomWBW and the other contains SCM. As a development platform you could build your own firmware in one Flash ROM while keeping a 'standard' working system in the other ROM - available at the flick of a switch.

You could use SC604 or SC613 instead of SC729. The 600 series are 40 pin modules while 700 series are 80 pin modules. All three are essentially the same electronics, so it's really more a cosmetic choice in the case of the CF modules. Spencer's CF module is another option which is functionally equivalent.

Earlier you mentioned wanting 8k ROM, and presumably 56k RAM. It should be noted that SC602 and SC714 only offer 32k banks, so the system resets with 32k ROM from 0x0000 to 0x7FFF, and 32k RAM from 0x8000 to 0xFFFF. Any 32k block from the 512k RAM and 512k ROM can be software switched into the bottom 32k of the Z80's memory map. Spencer's RC2014 ZED memory module is more flexible with 16k banks. Neither support 8k banks. If you really want 8k/56k split then Spencer's Paged ROM and 64k RAM modules, as used in the RC2014 Pro, are the only option available as kits (I think). This combination supports traditional CP/M but tops out at 64k RAM, so it will not run RomWBW.

If you want to implement your project as a CP/M application then the ROM size issue is likely irrelevant as the application will be loaded into RAM by CP/M. Pretty much any CP/M compatible system in the RC2014/RCBus ecosystem should allow you to do this. You could use a traditional 64k CP/M system, such as the RC2014 Pro, or a RomWBW hosted CP/M system, such as the RC2014 ZED.

RomWBW is fantastic. I think everyone should have this in their collection of RC2014 style retro systems. RomWBW's 512k ROM has everything you need to get started.

I think I've just made the selection process more complicated!

Steve

Michelle Lawson

unread,
Nov 7, 2025, 10:00:13 PMNov 7
to RC2014-Z80
I think at this point I'm leaning toward the RC2014-Pro kit. A question though; can the serial outputs be connected through an RS232 convertor (MAX232A or SP233A) to connect to PuTTY on a standard serial port (assuming that port works at 115K)? I'm leaning this way, because it is enough to get a base system up and running without too much of an issue, then I can add other boards as needed in the near future. And I guess I just go order it right from the web-link as well. Thanks

Phillip Stevens

unread,
Nov 7, 2025, 11:16:09 PMNov 7
to RC2014-Z80
I’d suggest to add the USB adapters from Spencer to your order too. The normal “Arduino” FTDI adapter has /DTR connected, which doesn’t allow the hardware flow control to operate. Spencer’s version has /RTS connected.

Also if you want to play with old IDE (PATA) hard drives make sure to add a Hard Drive Module from Spencer’s z80kits site to your RC2014 Pro.

I’d suggest using CP/M-IDE to drive the Pro with 64kB RAM. It is easier to use than the default build because it uses normally formatted (FAT) drives, and supports effectively unlimited* CP/M drives stored on the disks.

Cheers Phillip

*FAT supports up to 65,000 files per directory. 

Steve Cousins

unread,
Nov 8, 2025, 4:40:08 AMNov 8
to RC2014-Z80
I started with the RC2014 Pro. I wanted to design my own system but decided to start with known working hardware in order to develop my firmware (SCM). If I was starting today I would probably have gone for a RomWBW compatible system.

If a system can run RomWBW then with suitable software/firmware it can also run traditional CP/M 2.2 without using RomWBW's HBIOS. For example, with SC602 the SCM firmware includes a CP/M loader to boot CP/M from a CF card and configure the memory as a flat 64k RAM. I've not tested it but I believe it will also work on the RC2014 ZED system.

Your choice of software development tools might also influence your hardware selection.

Spencer Owen

unread,
Nov 8, 2025, 2:05:54 PMNov 8
to rc201...@googlegroups.com
On 08/11/2025 03:00, Michelle Lawson wrote:
> A question though; can the serial outputs be connected through an
> RS232 convertor (MAX232A or SP233A) to connect to PuTTY on a standard
> serial port (assuming that port works at 115K)?

Yes, any of these serial TTL / FTDI modules can be connected through a
MAX232 adapter, like the cheap modules on eBay with 9 pin D socket on them.

The RC2014 Pro has a dual clock module, which means that the second
serial port can be clocked at a slower speed than the rest of the board.
So even if you're connecting to an older terminal that doesn't support
115200 baud then you can just run that at a lower speed.

Spencer

Michelle Lawson

unread,
Nov 8, 2025, 4:32:00 PMNov 8
to RC2014-Z80
Fantastic, thanks. The size of this system (physical) will fit nicely into a box I made for another project that I banished. It has way more power that I will need, but..... And I found a pad-per-hole protoboard i want so I can test out some ideas. And I think the app I want to use it for, will work just fine running under CP/M 2.2. A side question though; how many disks is the CF card partitioned into?

Basically, this is going to be running all the time, acting as a 'server' for my other CP/M machines, along with a monitor of the AC power and alert my Dell servers to shutdown when power is lost. I will set this up so it runs on battery power when the power goes off as well. This is gonna be sweet! Thanks everyone.

Also, I have no Git presence, and everything I have done elsewhere (HW & SW) I let anyone have if they want, so..... The code is all Z-80 mnemonics and the hardware I do on KiCAD. 
Reply all
Reply to author
Forward
0 new messages