Hadware ignorant question - Jasmin / Microdisc

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Symoon
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Hadware ignorant question - Jasmin / Microdisc

Post by Symoon »

As far as I understood, there's a 8Kb ROM in the controller cards of Jasmin and Microdisc systems.
My question is: apart from this, are the controller cards different?

Would it be possible to have only 1 controller card and swap the ROMs to have the two systems?
Or even better, switch from one ROM to the other?
Simple curiosity.
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Re: Hadware ignorant question - Jasmin / Microdisc

Post by polluks »

Also the FDC registers are mapped at different addresses...
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Re: Hadware ignorant question - Jasmin / Microdisc

Post by Dbug »

They have different versions of the disk controller chip, they also use different registers for the interface I believe.
The bottom line is, it would be possible to abstract that very easily in software, so a Sedoric that runs on Jasmin is doable with some patching, but the low level code that access the hardware is different.
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Re: Hadware ignorant question - Jasmin / Microdisc

Post by Symoon »

Ok thanks. So anyone willing to have Jasmin and Microdisc drives in a single PC case will have to install both controllers, and up to 8 floppy drives ;-)
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Re: Hadware ignorant question - Jasmin / Microdisc

Post by Dbug »

Symoon wrote:Ok thanks. So anyone willing to have Jasmin and Microdisc drives in a single PC case will have to install both controllers, and up to 8 floppy drives ;-)
I guess technically it would probably be possible to make a system where the same 4 drives are connected to both disk controllers with some kind of switch on the flat cable :)
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Re: Hadware ignorant question - Jasmin / Microdisc

Post by Symoon »

You're right, though I just wondered if the Jasmin system is not limited to 2 drives. Not sure about this.

EDIT: just checked, it's four for Jasmin too \o/
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Re: Hadware ignorant question - Jasmin / Microdisc

Post by Godzil »

I'm not sure Jasmin+Microdisc will work flawlessly side by side. Anyway you will need a special DOS that will manage both.

If I remember correctly, the Jasmin need a precise IRQ handler, where the microdisc can be a bit more slowly, and so on.
Same, I'm not sure there is a way to know if the IRQ come from the Microdisc or the Jasmin...
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Re: Hadware ignorant question - Jasmin / Microdisc

Post by Symoon »

To me the idea was just to choose, either Jasmin, etiher Microdisc (with a switch, connecting the 4 drives to one or the other controller card), then boot.
Having both together... Didn't even think of that ;)
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Re: Hadware ignorant question - Jasmin / Microdisc

Post by jorodr »

I thing it's possible if manage IO signal - to go to Jasmin or to Microdisc. The question is if you want to make new controllers or you have both. If you have them I thing it's not difficult to build, but if you not, I don't know if it's possible to build new Jasmin, because of the PAL program. We have the schematics, but is there anywhere PAL content? If there is I thing it's not impossible to build dual controller. I thing to move my Microdisc compatible controller:

http://forum.defence-force.org/viewtopic.php?f=9&t=953

to CPLD somewhere in the future. Then it's not impossible to add Jasmin content.
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