Search found 156 matches

by mikeb
Mon Feb 10, 2020 5:52 pm
Forum: Demos
Topic: Real Time 3D example
Replies: 26
Views: 2023

Re: Real Time 3D example

Very nice demo -- now, if only there was a way to synchronize two Orics together, both running the same code, with same source data, but rendering from slightly different points of view (left, right), you could do a true 3-D display, one for each eye ... Oh wait ... http://forum.defence-force.org/vi...
by mikeb
Mon Feb 03, 2020 6:23 pm
Forum: Operating systems
Topic: Is BD-DOS lost to time?
Replies: 26
Views: 1072

Re: Is BD-DOS lost to time?

non-cable bit of a Byte Drive 500 to find out what's meant to be selectable from the machine — e.g. is there a side toggle? Is there a double-density toggle? From the article above, it seems the COB interface board for Oric is just there to provide an Oric (Atmos) specific boot ROM/hardware logic/W...
by mikeb
Sat Feb 01, 2020 8:41 pm
Forum: Operating systems
Topic: Is BD-DOS lost to time?
Replies: 26
Views: 1072

Re: Is BD-DOS lost to time?

Here is how the "Hybrid" cable looks: Well thanks for digging that up -- and "Yuck!" :( "revolutionary advance in the world of home computing" -- more like annoying retrograde step to prevent it ever being understood! Looks like both sides have COB (chip on board) under epoxy blobs, like used on di...
by mikeb
Fri Jan 31, 2020 5:25 pm
Forum: Hardware hacks and extensions
Topic: Securing sources of (official) Oric chips
Replies: 12
Views: 2437

Re: Securing sources of (official) Oric chips

Dbug wrote:
Thu Jan 30, 2020 8:35 pm
I'm now waiting for a few more chips (rams, 6502, soundchips, capacitors and tension regulator)
Sounds like you have a rare early clockwork version of Oric there ... :)
by mikeb
Thu Jan 30, 2020 5:43 pm
Forum: Operating systems
Topic: Is BD-DOS lost to time?
Replies: 26
Views: 1072

Re: Is BD-DOS lost to time?

possibly I'm wrong about the function of _both_ $311 and $317. $0310-$03FF is definitely going to be I/O to the disk hardware. Beyond that, ? If someone has a proper schematic of this board, then what the addresses do can be derived from the schematic, otherwise it's either guesswork or relying on ...
by mikeb
Tue Jan 28, 2020 9:34 pm
Forum: Operating systems
Topic: Is BD-DOS lost to time?
Replies: 26
Views: 1072

Re: Is BD-DOS lost to time?

0400 2C 11 03 BIT $0311 ; Unknown purpose. 0403 2C 17 03 BIT $0317 ; Unknown purpose. The comment from @iss relating to the other BIT instructions is a good observation, and it's always interesting when tricks like that slide into assembler :) The above two however I would say are NOT used to "hide...
by mikeb
Sun Jan 19, 2020 6:59 pm
Forum: Technical questions
Topic: ULA versions
Replies: 10
Views: 470

Re: ULA versions

You think they made millions of ULAs? Well, not literally ... but as no-one counted them at the time, can you prove otherwise ;) I don't know what the total production run was of all Oric-1 16k, 48k, ATMOS, all the derived machines being built in Europe, plus the mountain of chips lurking around Bu...
by mikeb
Sat Jan 18, 2020 5:57 pm
Forum: Technical questions
Topic: ULA versions
Replies: 10
Views: 470

Re: ULA versions

Would they have produced a new generation of ULA for the Atmos, or just continued with the same ones? They may have sent out for more batches, to keep up with production volumes, as 83 rolled into 84, but I don't think they changed the design internally. Oric to Atmos was: Better case and keyboard,...
by mikeb
Fri Jan 17, 2020 5:20 pm
Forum: Technical questions
Topic: ULA versions
Replies: 10
Views: 470

Re: ULA versions

No idea :)

I'd say that the photograph is from the underside of the chip. Turn your ULA over and have a look at what's written there ...
by mikeb
Thu Jan 16, 2020 5:47 pm
Forum: Technical questions
Topic: ULA versions
Replies: 10
Views: 470

Re: ULA versions

I was looking at a few of the motherboard photos, and ULA chips and ebay, and I was wondering if there was a difference between the various revisions. From what I've seen, we can find the following: - HCS 10017 | CDI-8B | 6809 ? - HCS 10017 | CDI / 8F | 8350 - HCS 10017 | CDI 8F | 8422 - HCS 10017 ...
by mikeb
Tue Jan 14, 2020 7:08 pm
Forum: Operating systems
Topic: Sedoric's TAKE command, help required...
Replies: 10
Views: 460

Re: Sedoric's TAKE command, help required...

>How did the 6502 designers miss the bug where addresses wrap around incorrectly (due to NOT incrementing the high byte) where things straddle a page boundary (effectively reading 0x5FF and 0x600 really reads 0x5FF and 0x500) ? :) Isn't this a feature - e.g. you might use it with zero-page shadow m...
by mikeb
Mon Jan 13, 2020 6:26 pm
Forum: Operating systems
Topic: Sedoric's TAKE command, help required...
Replies: 10
Views: 460

Re: Sedoric's TAKE command, help required...

how could this have been missed, and why has it never been removed? Sounds like an off-by-one error in dealing with the fact you've overshot 255->256 bytes, and the maths has compensated twice somewhere (as simple as a carry-bit set when ALSO adding 1 to the High byte, e.g.) Things like that are mi...
by mikeb
Sun Jan 05, 2020 7:03 pm
Forum: Technical questions
Topic: New Oric Project. The OriClone-1
Replies: 9
Views: 496

Re: New Oric Project. The OriClone-1

Also, why did they go with a 7905!!? The 7905 has a lower overhead (difference between the input and output voltage), which means it can still deliver 5v at a lower input than a 7805 would. So they stuck it in the ground leg, and regulated that instead of the +5v rail. The only time this causes a p...
by mikeb
Sat Dec 28, 2019 6:14 pm
Forum: Technical questions
Topic: Different tape input sound volume
Replies: 8
Views: 850

Re: Different tape input sound volume

One possibility -- check the Official "Oric Service Manual" for the various "mods" (resistors, capacitors) that need strapping on/moving around, some of which are to do with tape loading reliability. Maybe the difference is with/without these mods?
by mikeb
Thu Dec 26, 2019 6:31 pm
Forum: Demos
Topic: Real Time 3D example
Replies: 26
Views: 2023

Re: Real Time 3D example

jbperin wrote:
Wed Dec 25, 2019 11:10 pm
But I was ignoring that the TWO first columns was condamned. Thank you so much !!
I give you this commit number : 81eea6fbe4bcb190b69514f762495b7daba8d298
Glad that sorted it :)

Mike.