Re: C64 IEEE interface

Date: Wed, 05 Nov 2014 19:11:01 +0100
Message-ID: <>
Hallo Steve,

> I have two of these interfaces but not sure if they work or not.

I have two that don't work :( I would expect at least a start up 
message but nothing at all.

> ... plus the VIC-20 IEEE cart.

I have this VIC-20 cart, two C64 an one VIC-20 DAMS carts, and four 
carts containing a EPROM, 6821, 74LS245 and a 7417. Of those four 
6821 carts three didn't work: two because of a non-standard EPROM, 
one because of a brooken switch. All three worked fine with the 
EPROM of the first one.

> Do you have some sort of project in mind?

A member of our club bought a 8250LP and wanted to connect it with a 
C64 but didn't succeed because of a brooken interface. And I wanted 
to help him.
Instead of using the EPROM on one of those carts, I want to have a 
Kernal with a built-in IEEE driver: the main reason I asked how I 
could check my Kernals without RS-232 and Cassette interface. And 
IMHO it would look great to use an original C64 cart. So I wanted to 
implement the routines of the original EPROM into the Kernal. But 
someone took a lot of effort to make sure it is very very hard to 
disassemble the bloody thing :( That's why I asked if the job 
already has been done. 

FYI: I disassembled and commented 95% of the 6821 interface 
disassembled a great part of the DAMS one and I'm also busy with 
IEEE Kernal of the 64'er project from October 1985. I also made 
schematics of the DAMS and 6821 interfaces. If interested, as ausual 
everything is for free!

I want to be able to mix IEEE and IEC devices. And that just NOW 
pops up in my mind: if possible in combination with JiffyDOS (which 
means I have even more work to do). 
On possebility is to reserve a byte and using the bits to tell what 
device is or isn't IEEE. Another possebility, first check if a IEEE 
device is present and when not, assume it is IEC.
Any ideas or comments are welcome!

Kind regards / Met vriendelijke groet, Ruud Baltissen

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Received on 2014-11-05 19:00:03

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