Metku.net

MetkuMods
It is currently 23.10.2018 08:52

All times are UTC + 2 hours [ DST ]




Post new topic Reply to topic  [ 2 posts ] 
Author Message
PostPosted: 09.07.2009 13:00 
Offline
Regular Modder
Regular Modder

Joined: 02.11.2006 19:30
Posts: 249
I just got new programmer / debugger for my AVR -chips and my microcontroller / -processor interest became stronger again. Had little break from programming, but now I've started it again. I remembered that I have some pcb's with z80-stuff on them. Dad brang one device from his job with him, because they were going to throw it away, but dad knew I'd like to see what it "has eaten". I powered that device up and it seemed to work, I cycled through the menus and such. I think it was thrown away because it's used with old technology.
So... I just desoldered those z80-stuff from the boards and results are in the attachment. There are parallel and serial i/o -, counter / timer -, rom -, eprom (?) -, modem - and ram chips. Unfortunatelly CPU chip itself was already been disassembled and therefore it can't be used anymore.
I also got one chip from the memory cartidge... Seems to be all-in-one chip propably; has internal 8k rom and some ram, two uarts etc etc.

I've been trying to find out how to actually program these (the hardware stuff is what I haven't found out yet). First, where the program has to be programmed? In that rom-chip? That's my ques, but I've been browsing different projects and many times they are only talking about eprom programming and programmers (few guys have provided links to programs with their projects and they are eprom programmer programs).


Hommasin juuri uuden ohjelmointi- / debuggauslaitteen AVR-piireille ja tämä mikrokontrolleri/mikroprosessori kiinnostus yltyi. Tuossa oli pientä taukoa, kun oli kirjoitukset ja kaikkea muuta kiirettä, mutta nyt olen taassaanut ujutettua mikrokontrollerihommat jokapäiväiseksi aktiviteetiksi. Muistin että minulla on pari piirilevyä joilla on jotain z80-tavaraa. Isä toi joskus töistään romulavalta erään laitteen, joka kotona testatessani toimi ihan hyvin; selailin valikoita ja vikoja ei näkynyt. Laite on sellainen, ettei sillä yksityishenkilö tee mitään, joten purkuunhan se meni. Todennäköisesti se oli heitetty pois vanhentuvan tekniikan takia.
Äsken juotin irti nuo z80-rojut levyiltä ja liitetiedostossa on tulos. Siinä on rinnakkais- ja sarjaliikennettä varten piirit, laskuri / ajastin piiri, rom ja ram piirit, mahdollisesti UV:lla pyyhittävä eprom piiri (jokin UV:lla pyyhittävä se on... dataläpysköitä en ole vielä löytänyt) ja olipa vielä modeemipiirikin (äkkiseltään vaikutti olevan sarjaporttin kautta toimiva, "helposti" käytettävä). Valitettavasti itse prosessori on avattu ja siten toimintakunnoton.

Mitenkäs näiden z80-prosessorien ohjelmointi... Mihin se ohjelma sitten pistetään? Rom - piirille? Toisaalta voisi olla myös eprom, koska se oli ainoa piiri jossa oli erillinen kanta (=helppo irroittaa ohjelmoitavaksi...ihan vain arvaus). Monissa projekteissa puhutaan epromin ohjelmoinnista ja projektien tekijöiden antamissa linkeissä näkyy toisinaan ohjelmointiohjelmia ja nekin ovat epromin ohjelmointiin.



Sitten vielä pieni toivomus: Olisiko kellään jäänyt nuoruuden leikeistään ylimääräistä z80 prosessoria, jonka olisi halukas lahjoittamaan?

Jotain kysyttäviä asioita kuitenkin unohtui ja tekstissä on todennäköisesti paljon virheitä sekavuudesta puhumattakaan. Eiköhän näillä kuitenkin mennä nyt tällä kertaa.


Attachments:
File comment: z80-stuff
z80 004.jpg
z80 004.jpg [ 126.2 KiB | Viewed 1435 times ]
Top
 Profile  
 
PostPosted: 01.08.2009 22:46 
Offline
Regular Modder
Regular Modder

Joined: 02.11.2006 19:30
Posts: 249
Ok, so programs can be programmed to eprom (or other memories, but eprom keeps the data until it's erased, even after power goes off). There are 10+ pins for addres and 8pins for data. By using one dedicated pin, one can control when byte in datapins (d7,d6...d0 = **h) is programmed to addres, which is choosed by addres pins (a0, a1 etc). And if I remember right there is pin or two that needs to be controlled to indicate when chip is in programming mode. Programming can be made manually, using switches / keybad with decoder or with some kind of programmer, which takes in bytes with fe. serial port and decodes those bytes and programs them to the memory.
It would be kinda messy to use individual switches for every data and addres pins, so there are two ways left: programmer or keypad with decoder... If I have to start making something just for programming the memory, I could make programmer with atmega8 or something. It might actually be easier, than making decoder for keypad.

Atmega8 with serial input and multiplexer seems to be great way to start this project.

I got "all" the parts I need already (got the processor already, thanks to Gemis (if I remember that name right, have to check that out in irc some day), but haven't actually done any hardware or software. Software will be easy. In computer, reading the hex file and sending bytes through serial port to atmega8 which will set outputs pins accordingly and switching the controlling pin. Then atmega would do it backwards: read the bytes from eprom, send them to the computer and compare is it what was written there.
Hardware would be even easier, just normal serial link between atmega and computer, lots of wires between atmega and (multiplexer and) eprom.

After graduating from high school, it seems like I have less time to play with electronics, even though I don't have job or anything...:)


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 

All times are UTC + 2 hours [ DST ]


Who is online

Users browsing this forum: Exabot [Bot] and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group