CodeWalrus

Development => Hardware => Topic started by: Keoni29 on February 27, 2015, 08:02:09 pm

Title: Z820 - Z80 computer
Post by: Keoni29 on February 27, 2015, 08:02:09 pm
Original post: http://8times8.eeems.me:81/blog/index-beta.php?thread=16

This afternoon I started building this z80 computer. It will run at 20MHz, have 128K of ram and 8K of rom. The operating system will be stored on an external medium such as floppy disks.
https://www.youtube.com/watch?v=6uHxDewYHNQ
Title: Re: Z820 - Z80 computer
Post by: Snektron on February 27, 2015, 08:11:58 pm
Awesome *.* shouldve called the M80 though :P
I want to try to make my own 8-bit computer one day too, seeing your awesome projects >.>
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on February 27, 2015, 11:39:27 pm
It's more of a project name. The computer will get a proper name once I come up with a catchy one.
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on February 28, 2015, 12:43:57 am
Lol it has less ROM than the TI-81 :P (the 81 had 32K). Nice by the way, and good to see you managed to get a Z80 clocked at 20 MHz. :)
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on February 28, 2015, 03:48:59 pm
aeTIos gave me this z80 a while ago.
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on February 28, 2015, 04:45:12 pm
Ah that's cool of him ^.^
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on February 28, 2015, 05:09:37 pm
Just bought a bunch of parts. I got a 20MHz crystal, a bunch of capacitors and a connector for the floppy drive. I don't know which floppy drive controller I will use yet.
Title: Re: Z820 - Z80 computer
Post by: aeTIos on February 28, 2015, 07:31:32 pm
Cool to see that you can finally get that thing to do something ^.^ It's a bunch more useful for you than for me in any case :P
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on February 28, 2015, 07:50:42 pm
OMG where did you get those? O.O
Title: Re: Z820 - Z80 computer
Post by: aeTIos on February 28, 2015, 08:30:28 pm
Free sample from Zilog :P
Title: Re: Z820 - Z80 computer
Post by: Duke "Tape" Eiyeron on February 28, 2015, 08:34:10 pm
Seriously? Could i have one?
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on March 01, 2015, 12:12:12 am
Just ask and they ship em to ya.
Title: Re: Z820 - Z80 computer
Post by: Duke "Tape" Eiyeron on March 01, 2015, 01:22:40 am
Hell yeah, could you tell me where I could ask and what I could ask, please? :D
Title: Re: Z820 - Z80 computer
Post by: Juju on March 01, 2015, 02:12:06 am
Free samples? I should get this breadboard to use one of those times.
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 01, 2015, 05:58:10 am
Wait are you serious? O.O

If I get into electronics I hope I remember :P
Title: Re: Z820 - Z80 computer
Post by: Snektron on March 01, 2015, 10:36:50 am
i was actually thinking of building something myself, so im interested too o.o
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on March 01, 2015, 02:44:22 pm
The z80 I have comes in a plcc package which means you need a plcc to dip converter to fit it on a breadboard. I have not checked if zilog still makes the dip-style z80's (they probably do)
Title: Re: Z820 - Z80 computer
Post by: Snektron on March 01, 2015, 02:59:20 pm
On the site i was looking at they sold DIP 28 and DIP 40 actually, though they were only 6 Mhz ones
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 01, 2015, 05:11:04 pm
I am curious if Zilog will continue making 6 MHz CPUs in the near future with the TI-83+ slowly being phased out? I don't know if it will disappear from North America but I think it's only a matter of time.
Title: Re: Z820 - Z80 computer
Post by: Snektron on March 01, 2015, 07:52:41 pm
i don't think they're going to stop anytime soon, but meybe they'll just make less
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 01, 2015, 11:12:49 pm
I am curious about what else than TI calcs use a Z80, though.
Title: Re: Z820 - Z80 computer
Post by: Snektron on March 01, 2015, 11:33:54 pm
A Gameboy :P
also i heard it's the best sold cpu ever so yeah
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on March 01, 2015, 11:46:01 pm
Zilog sells all kinds of cpus and microcontrollers, but everyone just wants a z80 :P
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 02, 2015, 04:31:12 am
Seriously though, imagine if CodeWalrus decided to make its own gaming device or computer :P
Title: Re: Z820 - Z80 computer
Post by: Juju on March 02, 2015, 05:05:26 am
I found the free samples (https://www.samplecomponents.com/scripts/samplecenter.dll?ZILOG)~ Along with a Captain Zilog comic book (http://www.zilog.com/captain_zilog/)? o.o

Anyway, you should post a guide on how to order those free samples and pick the right ones.
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 02, 2015, 05:43:58 am
Lol those comics were kinda unexpected :P. I wonder if they are any good?
Title: Re: Z820 - Z80 computer
Post by: Duke "Tape" Eiyeron on March 02, 2015, 07:29:40 am
Quote from: Juju on March 02, 2015, 05:05:26 am
I found the free samples (https://www.samplecomponents.com/scripts/samplecenter.dll?ZILOG)~ Along with a Captain Zilog comic book (http://www.zilog.com/captain_zilog/)? o.o

Anyway, you should post a guide on how to order those free samples and pick the right ones.


They lost a so-good visual pun there! See, Captain Zilog and his Chip-munk sidekick! :trollface:
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 02, 2015, 05:13:12 pm
Oh wow, those puns XD. I wonder if one of those comics involves a battle against ARM and 68K nations or something? :P
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on March 02, 2015, 10:47:26 pm
AVR does have a super hero of their own...
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 03, 2015, 12:10:54 am
AVR Man vs Captain Zilog :P
Title: Re: Z820 - Z80 computer
Post by: Duke "Tape" Eiyeron on March 03, 2015, 06:16:13 am
Each one must gather INTELligence from the other side to win the Dual(core) sided war.
Title: Re: Z820 - Z80 computer
Post by: aeTIos on March 03, 2015, 06:16:38 am
Quote from: Juju on March 02, 2015, 05:05:26 am
I found the free samples (https://www.samplecomponents.com/scripts/samplecenter.dll?ZILOG)~ Along with a Captain Zilog comic book (http://www.zilog.com/captain_zilog/)? o.o

Anyway, you should post a guide on how to order those free samples and pick the right ones.

It's ages ago since I ordered that sample, I don't even exactly know how to order them anymore, will look into that (and order another one, I guess?). And yeah that Cpt. Zilog book is pretty cool :P
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on March 03, 2015, 06:55:47 am
This is intel's super hero:
(https://codewalr.us/proxy.php?request=http%3A%2F%2Fi.ytimg.com%2Fvi%2FlGn6XImwVD4%2Fmaxresdefault.jpg&hash=4ee471e74a9efc1f20c28b48569d52dd)
I wonder what ST, TI and Microchip are going to come up with.
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 03, 2015, 03:30:53 pm
This better be a mage, because I don't think he'll stand a chance against Captain Zilog :P


If TI gets a Superhero it will probably behave erratically at times, because of bugs, and probably be cheap in production because TI will have done everything to keep production costs to a minimum. :P
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on March 03, 2015, 08:05:20 pm
I got the serial output to work with the PC16552D UART chip. There were some dodgy solder joints that caused problems with it, but I tracked them down and resolved the problem.

It prints characters at 960 Bytes/second right now, but it can go up to 125kByte/second.
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on March 04, 2015, 08:02:57 am
I ported the bootloader I made for the cbs6000 to z80 asm. It works great :D
Source can be found here: https://github.com/keoni29/z820
Title: Re: Z820 - Z80 computer
Post by: Snektron on March 04, 2015, 08:07:42 am
Quote from: Keoni29 on March 04, 2015, 08:02:57 am
I ported the bootloader I made for the cbs6000 to z80 asm. It works great :D
Source can be found here: https://github.com/keoni29/z820


"Error: does not execute properly" ? :P
Anyway nice progress :D
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on March 04, 2015, 11:12:51 pm
Yeah I should get rid of that :P That should have been taken down after I fixed the bug.

I am busy writing a monitor program which allows me to poke around in memory and debug stuff. I based the monitor off the one I have on the cbs6000 computer.
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on March 05, 2015, 11:28:56 pm
I finished porting the monitor and it works great! It's just like the one on the CBS6000. I learned a lot about the z80 in the process.
Source can be found here: https://github.com/keoni29/z820/blob/master/mon.asm
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 06, 2015, 06:40:10 am
(off-topic: Your avatar is scary and reminds me of AVGN :P)

Also good job. :D By the way, as you work on this computer and learn about the processor, did you gain some interest in learning TI-8x ASM as well? :)
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on March 06, 2015, 07:03:35 am
I have done a bit of asm programming for the cse in the past, but not much else yet.
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 06, 2015, 07:10:17 am
Oh wait you did CSE stuff? I totally forgot. By the way do you like the language or do you prefer higher level ones?
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on March 06, 2015, 10:14:23 am
Depends on the task at hand. When I need to do stuff close to the hardware I prefer using asm. When stuff gets more complex I usually move on to C, but sometimes I just work with asm to keep things consistent.
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 06, 2015, 05:19:47 pm
What about games? (Eg something like Herocore or Zelda)

Also I wonder how fast would such game be on your computer :P
Title: Re: Z820 - Z80 computer
Post by: Keoni29 on March 06, 2015, 09:44:33 pm
That depends on the screen I guess.
Title: Re: Z820 - Z80 computer
Post by: Snektron on March 06, 2015, 09:57:33 pm
Quickly! use a HD 4x4 pixel screen!
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 06, 2015, 11:56:56 pm
An rpg with a 3x3 screen would be possible. :P (Illusiat 1 style)
Title: Re: Z820 - Z80 computer
Post by: Snektron on March 06, 2015, 11:59:34 pm
That would be quite a fun challenge actually :o
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 07, 2015, 04:20:26 am
Indeed. That said, it doesn't necessarily have to be on Keoni's computer. It could just be a maze game that mimics a 3x3 screen on any platform. Maybe a mini-contest :P
Title: Re: Z820 - Z80 computer
Post by: Snektron on March 07, 2015, 12:51:52 pm
A screen shader that turns everything into 3x3 pixels *.*
also "mini" contest, i see what u did there (https://codewalr.us/proxy.php?request=http%3A%2F%2Fwww.myfacewhen.net%2Fuploads%2F3749-i-see-what-you-did-there-no-text.png&hash=06e759756f9a9bfd385f9aa5d23cd470), but that's indeed something we could maybe do
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 07, 2015, 06:57:18 pm
By turning wverything into 3*3 pixels do you mean that makes the screen look more pixelated or do you mean that it zooms in?

And lol no pun was intended but I just saw it now O.O
Title: Re: Z820 - Z80 computer
Post by: Snektron on March 07, 2015, 07:04:40 pm
Pixelated, yes, it wouldn't een be that hard :P
Title: Re: Z820 - Z80 computer
Post by: DJ Omnimaga on March 07, 2015, 07:09:58 pm
It depends. It might be slow on some calcs if the routine has to pixelate the screen every frame. I once made such routine in Axe and it slowed things down quite a lot.

On the HP Prime, on the other hand, it's a piece of cake:

(https://codewalr.us/proxy.php?request=http%3A%2F%2Fimg.ourl.ca%2F%2Fssballfadein.gif&hash=b88c46d9720ca3ce849c26ae65003245)

We should probably get back on-topic, though. :P
Title: Re: Z820 - Z80 computer
Post by: Snektron on March 07, 2015, 10:25:46 pm
I actually meant a pc shader, but axe would probably be quite fast too