Oric Hardware Programming How-To
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plus Data Sheets
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The ULA as viewed by Michael Brown
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(also in ascii format with figures in Xfig
or
Postscript format. And an history
too)
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Oric Schematics
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Oric Motherboard, parts 1
and 2
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Microdisc controller, parts 1
and 2
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Telestrat's motherboard pictures
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parts 1 and
2
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The hardware page !
Picture gallery
of Oric computers for the 3rd Millenium
DIY serial interface
Here is a serial interface that you can build yourself, it uses only 4 chips !
It is compatible with the microdisc controler, and it uses the $031C-031F
address range like on the Telestrat. The diagram is
here, and the connection list
here.

A simple cable to catch the vertical retrace signal !
If you have developed games on the oric, you know that moving objects smoothly
on screen is not easy because you don't have any way to synchronize with
the CRT and so your objects are subject to flicker. Well, just build a
two-headed cable from your existing RGB cable, with only one wire to solder
from the SYNC pin of the RGB DIN plug to the TAPE IN pin of a new tape
DIN plug, et voilà ! Then, every vertical retrace pulse will generate
a corresponding interrupt thanks to the VIA (CB1 flag). New demos are going
to show the benefits of this simple wire, and some people are patching
old games to remove the flicker.
An interface to standard
Apple2 disk controllers
Yes, thanks to George Dramcheff from Bulgaria, you have the opportunity
to connect an Apple2 disk controller to your Oric. The interface is easy
to built, just have a look at the
schematics George sent me. If you are desperately looking for a disk
controller, it might be easier to find one for the Apple2 and to build
this interface. However, if you are looking for a genuine Oric disk controller,
of course it's not the same thing. Here are the pros and cons of this interface
:
pros: it allows you to read Apple2 disks, this is great if you have
Apple2 disks and want to have a try at porting some software from the Apple2.
The interface has few components, it might even be simplified/enhanced.
Apple2 disk size is 5"1/4, that's easier to find than 3" disks.
cons: you can't read Oric or PC floppy disks with it (Apple2 disk
controllers use GCR encoding, not MFM), and standard Apple2 drives are
single-sided (a standard 5"1/4 Apple2 disk has a formatted capacity of
140 KB)
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