Z80-MBC2

Strider · Post by **Strider** » Sun Jun 26, 2022 10:48 pm

I have been seriously looking at building a Z80-MBC2 to play around with for a few different reasons.

I never had the opportunity to really play with CP/M, and I always wanted to.

It's an inexpensive "retro" computer you can build yourself.

It just looks like a lot of fun to play around on.

Watching Adrian's SWTPC 6800 videos rekindled my interest in computers of that style and era, and the Z80-MBC2 is cheap modern "DIY homebrew" way for me to have some fun and scratch an itch I have had for some time.

Yes, you can do it in an emulator, but this is one case where having actual hardware, getting to put it all together yourself, just makes more sense to me. I mean, I like to build things, so why not?

My question is, has anyone here built one yet? If so, what do you think?

If not, do you plan on it?

I know @BruceMcF mentioned the Z80-MBC2 a while back.

I have everything downloaded, the PCB's are on eBay for $9. Or I could order a set of 5 of PCBWay for under $20 if I really wanted to, but, I don't really need 5 boards.

I already have most of the supporting electronics and connectors, and tracking down the necessary ICs is pretty simple. The only things I need to figure out yet are the RTC, USB serial, and SD modules.

Any suggestions? ?

UPDATE: I'm documenting the full build on my blog! https://theclassicgeek.blogspot.com/

kelli217 · Post by **kelli217** » Mon Jun 27, 2022 7:37 pm

Just a few months ago I was looking at the RC2014 project. It's very similar.

Strider · Post by **Strider** » Mon Jun 27, 2022 8:12 pm

On 6/27/2022 at 2:37 PM, kelli217 said:

Just a few months ago I was looking at the RC2014 project. It's very similar.

I was looking at the "Classic II" version. I really liked the "out-of-box" support for MS Basic, and the $85 price for the full kit isn't all that bad in my opinion. In fact, I am still considering it, but the Z80-MBC2 crept to the top of the list becasue I already have most of the parts, and the ICs are still pretty cheap and easy to find. I can build the thing easily and cheaply, then maybe look into something like the Classic II if I like the Z80-MBC2.

Like I said, this is all to scratch an itch I never got to scratch, I don't want to spend too much time and money on it until I know what I'm getting into.

Also, truth be told, this is something to keep me busy until the X16 becomes available in a form I can get my hands on, something to play with. ?

BruceMcF · Post by **BruceMcF** » Sat Jul 02, 2022 9:49 pm

On 6/27/2022 at 4:12 PM, Strider said:

I was looking at the "Classic II" version. I really liked the "out-of-box" support for MS Basic, and the $85 price for the full kit isn't all that bad in my opinion. In fact, I am still considering it, but the Z80-MBC2 crept to the top of the list becasue I already have most of the parts, and the ICs are still pretty cheap and easy to find. I can build the thing easily and cheaply, then maybe look into something like the Classic II if I like the Z80-MBC2.

Like I said, this is all to scratch an itch I never got to scratch, I don't want to spend too much time and money on it until I know what I'm getting into.

Also, truth be told, this is something to keep me busy until the X16 becomes available in a form I can get my hands on, something to play with. ?

I still harbor hopes of trying to do a "CP/M User Box". It would not be BASED on the Z80 MBC2, but the Z80 MBC2 might be an excellent starter project to get my feet wet before trying to hammer out anything of my own. I might even pursue it in two stages -- a 4MHz breadboard version and then a faster PCB version.

Strider · Post by **Strider** » Sat Jul 02, 2022 10:14 pm

On 7/2/2022 at 4:49 PM, BruceMcF said:

I still harbor hopes of trying to do a "CP/M User Box". It would not be BASED on the Z80 MBC2, but the Z80 MBC2 might be an excellent starter project to get my feet wet before trying to hammer out anything of my own. I might even pursue it in two stages -- a 4MHz breadboard version and then a faster PCB version.

I am actually doing a bit of shopping around right now for two different projects, one of them being the Z80-MBC2, I pretty much have my heart set on building myself one. You'll have to let me know how yours goes.

The other project is building a DOS/Win95 "retro" computer for some old school fun, with some modern amenities like using an IDE SD adapter instead of a HDD and a floppy emulator (maybe). ?

BruceMcF · Post by **BruceMcF** » Sun Jul 03, 2022 2:19 am

On 7/2/2022 at 6:14 PM, Strider said:

I am actually doing a bit of shopping around right now for two different projects, one of them being the Z80-MBC2, I pretty much have my heart set on building myself one. You'll have to let me know how yours goes. ...

If I am still in my current situation of working hard for long hours to help save up money to build a house, any hardware project is "not now". However, if I land a teaching position out of state where I am coming back to home base on the weekends and vacations, then I could be looking for something for weekday evenings this coming September, and will surely share whatever I find out (whether successes or 'successes at finding out what doesn't work') in these forums.

Strider · Post by **Strider** » Wed Aug 24, 2022 5:30 am

I just ordered the Z80-MBC2 and uTerm VGA Terminal PCBs on eBay, and an RTC on Amazon. I have most of the necessary resistors, capacitors, and connectors on hand, I just need to track down the ICs and everything else. ?

https://www.ebay.com/itm/283494335966

https://www.ebay.com/itm/283877042508

https://www.amazon.com/dp/B07Q7NZTQS/

Tatwi · Post by **Tatwi** » Wed Aug 24, 2022 7:59 pm

TTY only graphics, no sound... So close man, so close!

The X16 is over-engineered, "too much" really. There's something to be said about a ZX Spectrum with a faster CPU, more RAM, and SD card storage - Would it be amazing? No. Does it need to be? No!

If someone made rudimentary graphics and sound for the Z80-MBC2, along the lines of the ZX Spectrum, then it would be an ideal little retro computer to do retro things with. Something between "too much", "not enough", and "the Colour Maximite is weird".

Strider · Post by **Strider** » Wed Aug 24, 2022 8:58 pm

For me, the attraction is the fact I never really got to mess with anything like this, I started on a TI-99/4A and moved right into Commodore from there. I never went back far enough to mess with this sort of computer.

I watched Adrian Black's video series on the SWTPC and it hooked me. I just loved how it all worked, the raw nature of it, and this is a way for me to play around with a modern incarnation of something right out of that era. Plus, the Z80 isn't something I got to really use either. It all just sound like fun to me, as does building it.

I also think building something is just as fun as using the final product, that's why I want the X16 in a kit "DIY" form.

?

Tatwi · Post by **Tatwi** » Wed Aug 24, 2022 11:12 pm

On 8/24/2022 at 4:58 PM, Strider said:

I also think building something is just as fun as using the final product, that's why I want the X16 in a kit "DIY" form.

Can't argue with that!

On 8/24/2022 at 4:58 PM, Strider said:

For me, the attraction is the fact I never really got to mess with anything like this, I started on a TI-99/4A and moved right into Commodore from there. I never went back far enough to mess with this sort of computer.

Software wise, no one needs real retro computer to have an authentic TTY experience, because almost any keyboard/screen combo can be attached to perfect software emulation on the other end. Using CP/M while sitting a real DEC VT-100 would feel very retro even if the OS is provided by a dusty old PC that's aging gracefully under a desk 500 miles away. It's for this reason that I feel the "human interface devices" are more important for the overall retro experience than the computing circuitry, with the only exceptions being if one wishes build, modify, or study the hardware. For instance, I don't generally use VICE on my desktop, because it just feels like I am using my desktop, because... I am using my desktop. Now if I invested in a Commodore monitor and a Keyrah for my VIC20, I'd be happy to use VICE in that setup, because it would feel like I am using a VIC20/C64 (especially if I tortured myself by using a tape deck too lol).

Anyway, I encourage you to consider the ways you can fully immerse yourself in the era to get the most out of the experience. An old looking screen, an old feeling keyboard, a few vintage magazines and books, the oldest coffee mug you can find, and your phone shoved to the back of a drawer where it can cease to be a yammering naggy-pants for an hour... Maybe a stale ashtray for maximum authenticity... Live the dream, man! ?