KimCard - KIM-1 6502 Single Board Computer Emulator

[petersieg]

Hi. I located the githup repository, with pcb (eagle) files and source.
In the eagle files, no values are given for:
R1..R8 - its for the 7-segment led's, therefore I assume 220 ohm?
R13 ..R18 - its for the transistor basis - I assume around 1k?
I think R20 ..23 are not needed right now?
Transistors Q1 ..Q6 are any standard PNP type?
And the 7-segment displays.. is that KCSA3? Source to them? Compatible types? (It's common anode)

I might order one KimCard-r3 pcb for myself..

Just downloading atmel studio 6 (have just used 4.18 for atmega1284p, atmega328p etc.)

Peter

[matseng]

In the revision 2 of the board I used very small thru-hole NOS 7-segment displays, but since they are hard to find I've changed them to modern smd displays instead. They are standard Kingbright KCSA03-101, I got a bunch of them from my local Element/14Farnell.

For the rev2 board I used 68 ohm for display current limiting transistors R1-R8. (Remember we're running at 3.3 volt and multiplexing the displays)

The base resistors R13-R18 I used 2k2, and the PNP transistors are just a standard jellybean part. I just grabbed some from my parts drawers, they're probably an smd version of BC549.

The USB resistors R22/R23 might be left out but I'm usually put 22 ohms there out of habit.

The i2c pullups R20/R21 are required - I actully had to patch them there on the rev2 board since the internal pullups in the xmega is not enough for the i2c bus. I used 3k3 but 4k7 should be ok as well.

Studio 6 takes a while to get used to, I've been a long time 4 -user but I'm now slowly warming up to 6.

If you want to solder one up and play with it while I finalize the rev 3 board I can send you a rev 2 pcb and the displays for free. (but it needs to be patched with the i2c pullups and make the ugly patch for the usb connector)

[matseng]

There are two versions of the xmega32chip.

atxmega32A4 (with internal usb and crypto engine)
axtmega32D4 (no usb, no crypto)

The A4 can't be exported outside USA without an export license

So I connected the usb data-lines both directly to the xmega (in case of A4) and to a PT201 usb/i2c bridge chip that can be used if only the D4 chip is available.

But the PT201 might become necessary when using the A4 as well since the program space in the xmega32 is only 32 KB and a huge chunk of it is used by the emulator so the firmware for usb might not fit there...

[petersieg]

Yes! To get a r2 pcb with the hex displays would be just great! Many Thanks!

---

Does that mean, I should not yet make a r3 board?

---

I build the KimCard project and got a hex file under simulator subdirectory..?
I that the one to use? Can't get it to place it under release subdirectory..

---

I have just ordered a avrispmkII compatible programmer for 20€..

---

Best regards,
Peter

[matseng]

I'll download the code from github for a clean test and see what's up with the simulator vs. release issue.

Meanwhile PM me you address and I'll drop it in the mail tomorrow.

[petersieg]

Jup. Should have my address by now (PN). Have also ordered some other parts.. might need to check on LDO, if same pinout etc.
Also could not yet get max1555.. Ordered atxmega32a4.

Peter

[matseng]

I just arrived in Hong-Kong for the Global Geek Asia tour in HK and Shenzhen, so I won't be home until next Friday. I'll post it to you then.

[petersieg]

Hi.

Sounds like a lot of fun to travel to HK and a geek show ;-)
When you are back, maybe you could give me the manufacturer and exact type of the r2 7-segment through hole displays with common anode. I will try to locate them also here in Germany (or some shops outside).

(But please send them also together with the r2 pcb, so at least I have enough to get one r2 board working).

The max1555 is available at de.mouser.com, but since this one is only for lipo charging etc. I might skip it for the time being.

Thanks, Peter

[matseng]

I actually brought a KimCard-r2 and my AVR Dragon with me so I could hack on it while I'm here. :-)

The displays are TDSR 1153 http://www.aet.com.pl/Portals/0/ZelNet_ ... SR1150.pdf

I'm thinking of possibly changing the MAX1555 to a more modern and common charger for the r3 boards...

[simpleavr]

hello,

just read this thread via the blog entry. i am also interested in retro-computing (my 1st computer is one of the early 6502 sbc, an ohio superboard 2).

i am also working on a similar project and thought may be some of u are interested. it's based on the $4.30 ti launchpad and is very compact.

paradiso ui boost

there are no active components on the design (except led modules), leds are driven directly by the launchpad, as well the tactile buttons are scanned.

currently it does a LMC (little man computer) emulation and i am about to finish a msp430 assembler / disassembler (one pass).
it got a minimal monitor to allow for programming editing, 32 segments of 256 bytes of flash are allocated as program storage.
there is may be about 128 bytes of RAM available to execute programs.

i also thought of emulating other CPUs but as the launchpad is not very powerful (i am using a msp430g2553), it will require additional components (like spi ram, etc).


below is a video showing entering and executing a LMC program.

http://youtu.be/HNK9imVcz_E

hope u enjoy.

[matseng]

Nice project... The Ohio Superboard looks a bit familiar, I think the hobby computer shop that I was hanging around at in the late seventies hand one of those, but I'm not 100% sure. But they definitely had an Exidy Sorcerer and a Imsai 8080 and some other S-100 bus computers...

The LMC is really a "blast from the past", I haven't read about that for a long time. I think I have to make an emulator for that on my board as well. Hm.... It would be fun to do that emulation inside the KIM-1 emulator. An emulator inside an emulator - Inception!

[petersieg]

@matseng: Do you have received my address? Send it twice now..?

@simpleavr: Do you have a web space with more information (firmware; schematic; eagle files; sourcecode; examples; etc.). I think I still have 3 of those TI lauchpads lying around.. ;-)

Peter

[matseng]

Yup, got your address now. I'll post the envelope tomorrow....

[simpleavr]

@peterseig
i am still working on the write-ups and such. this project is intend to be entered in a "project of the month" contest in 43oh.com. i will make available the full project with proper write-ups in a week of so. i will provide a short link here if mateng don't mind. i had no intention to hijack this thread. just thought i had a similar project that would like to share, may be contribute to the topic.

if u can't wait, there is a skimmed down source file that contains the ascii art schematic here http://forum.43oh.com/topic/2891-paradi ... ge__st__20

[simpleavr]

Nice project... The Ohio Superboard looks a bit familiar, I think the hobby computer shop that I was hanging around at in the late seventies hand one of those, but I'm not 100% sure. But they definitely had an Exidy Sorcerer and a Imsai 8080 and some other S-100 bus computers...

the superboard 2 is closer to apple 2 in that it got full keyboard and video out instead of hex display / keypad. i had my hands on a microprofessor (the pre-acer acer made them) and that hex display setup got me into programming. it is really simple and straight forward so i always want to re-produce that type of setup. i know about the kim-1 but never touched one. i guess back then w/o internet we all got our feeds from byte / radio electronics / circuit celler articles.

The LMC is really a "blast from the past", I haven't read about that for a long time. I think I have to make an emulator for that on my board as well. Hm.... It would be fun to do that emulation inside the KIM-1 emulator. An emulator inside an emulator - Inception!

i actually don't know about LMC back then, only recently and i found it simple enough so i tried and implement this 1st before digging into other emulations. i do think its very useful (although not practical) in explaining assembler / machine code concepts. appreciate your sharing of your work.