FAT formatted SD-card interface for Micro-KIM with tape emul

Talk about your Micro-KIM

Postby vbriel » Jan Fri 30, 2009 8:55 pm

Hi Dex,

Great idea, I'll have to look at the code if I can grab a few minutes. Just glancing, the MMC2IEC is I2C, correct. A000 is perfect place for the DOS because the 32K RAM card is 2000-9FFF. And the 6522 at C200, I guess this all just works out using the Multi I/O board, what luck. Guess we should make an adapter for the Micro-KIM to Apple 1 slot interface?

Do you have have the 6522 connected yet? Do you need any schematics or anything else?

Something to remember, when the jumper is on for the onboard memory decoding, the memory is shadowed every 8K. So, 0000-1FFF is the same as 2000-3FFF (not my design, talk to Chuck Peddle). If you want to use the Multi I/O board, you will have to make some new memory decoding design. I did this for the 32K RAM chip and that is why you remove the jumper when you install the 32K RAM.

Vince
User avatar
vbriel
Site Admin
 
Posts: 1184
Joined: Jul Tue 19, 2005 12:10 pm
Location: Ohio

Postby hanso » Feb Sun 01, 2009 6:04 am

vbriel wrote:.... Just glancing, the MMC2IEC is I2C, correct.
Vince


Its not I2C, its IEC, a serial form of IEEE.
All peripherals made by Commodore, after the PET and such, were intelligent serial IEC devices. Disks, printers. A bit slow due to a bug in the 6522 serial shift out implementation.

The MMC2IEC is open hardware and software. The SD2IEC is a successor (also open hardware and software) which can be bought assembled, but is identical for this purpose.

To DEX: great idea. I have a Commodore 1541 connected to my KIM-1 via the same adapted SYM--1 sources. Works fine, and fast enough. I never found time to reroute the cassette routines to the IEC disk drive, I just replaced the I/O in the programs (Micro Ade, KB9 basic).
The MIcro-KIM does not have a 6522 (and it really needs a 6551 ACIA too) yet, so I an quite interested in your experiments.

Your design for a 6522/EEPROM needs some address decoding I assume?
A few 74ls138/139 could be all you need.
Would be nice to see how the 32KRAM decoding works, Vince did not publish the circuit diagram yet.
hanso
 
Posts: 71
Joined: Sep Sat 22, 2007 12:35 pm
Location: Weesp The Netherlands

Re: FAT formatted SD-card interface for Micro-KIM with tape

Postby chassum » Mar Sun 03, 2013 5:31 pm

I realize this thread is _very_ stale, but I am interested in the prospect of using an sd card as a drive for the Micro-KIM. Has anyone actually done this? I would (probably) use FIG-forth as the OS. Any pointers would be very much appreciated.
User avatar
chassum
 
Posts: 23
Joined: Apr Mon 23, 2012 1:53 pm

Re: FAT formatted SD-card interface for Micro-KIM with tape

Postby vbriel » Mar Wed 06, 2013 10:16 pm

Actually it is possible with the Propeller microcontroller. I have written firmware that allows the Propeller to act as RAM to the 6502 so you can read/write memory and that can be used to read/write to a disk image or file of some type. Since there was no OS disk controller that I'm aware of for the KIM-1, there is nothing to emulate, only create :)

Vince
User avatar
vbriel
Site Admin
 
Posts: 1184
Joined: Jul Tue 19, 2005 12:10 pm
Location: Ohio

Re: FAT formatted SD-card interface for Micro-KIM with tape

Postby chassum » Mar Thu 07, 2013 7:36 am

Sounds very interesting. Is this something you are going to productize? I had been looking at something like this:

https://www.adafruit.com/products/254
User avatar
chassum
 
Posts: 23
Joined: Apr Mon 23, 2012 1:53 pm

Re: FAT formatted SD-card interface for Micro-KIM with tape

Postby vbriel » Mar Thu 07, 2013 4:46 pm

No, this is just a level converter breakout board, what I want to do is a full interface. So, you can say, address it to address B000, or something like that. Have one memory location be a command register like read or write byte, the other location will be the data address, just like on a disk controller. I'm working on something very similar to this right now so I may have something later to post online about it.

Vince
User avatar
vbriel
Site Admin
 
Posts: 1184
Joined: Jul Tue 19, 2005 12:10 pm
Location: Ohio


Return to Micro-KIM General Discussion

Who is online

Users browsing this forum: No registered users and 1 guest

cron