Commodore IEC interface for the Oric

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Bacon
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Commodore IEC interface for the Oric

Post by Bacon » Fri Aug 18, 2006 11:13 pm

Has anyone thought of making an Commodore IEC (serial) interface to connect a Commodore disk drive to the Oric? I don't know much about electronics, so I may be completely wrong here, but it seems to me that it wouldn't be very hard to make a small board with a modified ROM and a DIN socket and connect it to the BUS expansion. It has the same interface chip as a VIC-20 (the 6522 VIA) with all the lines available on the expansion port.

You could then replace the tape routines with the disk routines from the VIC-20, making it compatible with most existing software. A switch could be installed on the interface board to swith out the modified ROM and use the normal ROM when you need tape access.

IMHO this would make sense for those of us who don't have an Oric disk drive, since they seem to be hard to get, while Commodore disk drives are readily available (although very slow :? ). You could even connect it to a PC running C64HDD.
Bacon
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Dbug
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Post by Dbug » Sat Aug 19, 2006 11:13 am

Well, this definitively sounds like a good idea.
I'm not an hardware guru, but sure it could be nice :)

Now of course there would be the problem of operating system compatibility, and doing disk based demos that would work on microdisc as well as on C64 drives could be an interesting programming challenge :)

Bacon
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Post by Bacon » Sat Aug 19, 2006 1:00 pm

My thinking was that you could replace the cassette routines with the VIC-20 disk drive routines, so that the Commodore drive would look like a tape player to the Oric/Atmos BASIC, i.e., you'd use CLOAD and CSAVE to load and save to/from disk. It wouldn't work with custom tape routines of course :?

Making it compatible with microdisks would be even nicer, but that would be a harder challenge, I'm sure.
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Post by Dbug » Sat Aug 19, 2006 1:11 pm

Well, I sure want to keep the cload/csave code, it's what I use for all my small tests, using "tap2cd" to transfert programs between PC and Oric. That's the fastest way to do it.
There are probably other parts of the ROM that can be removed without too much harm - like the handling of specialy formated tape files.

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