Search found 98 matches

by ThomH
Thu Apr 26, 2018 8:40 pm
Forum: Technical questions
Topic: 8DOS: overlay RAM control?
Replies: 3
Views: 48

Re: 8DOS: overlay RAM control?

I guess the engineers at Pravetz really internalised the idea of soft switches! So you can put almost any other Apple II card into the other slots and expect to be able to talk to it? Was there any software support for that? Presumably subject to limitations, which I would guess(?) to include: the 2...
by ThomH
Thu Apr 26, 2018 6:29 pm
Forum: Technical questions
Topic: 8DOS: overlay RAM control?
Replies: 3
Views: 48

8DOS: overlay RAM control?

Documentation seems to be extremely slender on 8DOS, so here's what I currently think I know. From iss I've learnt the fundamentals necessary to support 8DOS v1: the boot ROM is visible from $320 to the end of that page; and the Disk II controller registers are exposed from $310. Per the Fastload so...
by ThomH
Thu Apr 26, 2018 2:35 pm
Forum: Emulators
Topic: JOric
Replies: 51
Views: 1743

Re: JOric

I'd also vote in favour of maintaining the proper aspect ratio, especially when you consider the pixel densities of modern Android devices, and the direction that pixel density continues to head. In Clock Signal I apply a discreet lowpass filter to suppress some of the resulting aliasing; have you c...
by ThomH
Wed Apr 25, 2018 9:08 pm
Forum: Operating systems
Topic: FastBoot/FastLoad on Pravetz 8D/Disk II
Replies: 27
Views: 1342

Re: FastBoot/FastLoad on Pravetz 8D/Disk II

The emulation in Oricutron is very far from perfect, I added it to be able to run DOS-8D and some interesting old software and until now there was no demand for something better, but this will change and I think to add NIB support, which will provide as side effect the possibility to use any interl...
by ThomH
Thu Apr 05, 2018 3:49 pm
Forum: Emulators
Topic: Oricutron and Mac Sierra and High Sierra
Replies: 15
Views: 1798

Re: Oricutron and Mac Sierra and High Sierra

and you can virtualise old versions of OS X going back to 10.4 which was the first version on this side of the Intel transition. In my (somewhat limited) experience, running OSX in a VM was good enough for normal applications, but it gave terrible performance for games or anything relying heavily o...
by ThomH
Thu Apr 05, 2018 3:01 pm
Forum: Emulators
Topic: Oricutron and Mac Sierra and High Sierra
Replies: 15
Views: 1798

Re: Oricutron and Mac Sierra and High Sierra

Sorry, to be clearer about prejudice: my day job for almost a decade was iOS development, both in iOS-first organisations where everything tended to be smooth and easy and in the furthest possible thing you can get from an iOS-first organisation, where there was a natural desire to plug iOS developm...
by ThomH
Tue Apr 03, 2018 3:51 pm
Forum: Emulators
Topic: Oricutron and Mac Sierra and High Sierra
Replies: 15
Views: 1798

Re: Oricutron and Mac Sierra and High Sierra

It might say more about my abilities than anything else, but I find that keeping up to date with Xcode is a worthwhile aim in itself just because the surrounding tooling is always improving. E.g. the latest version of the runtime analysis tools pointed out the undefined behaviour in (heavily simplif...
by ThomH
Sat Mar 31, 2018 9:39 pm
Forum: Emulators
Topic: JOric
Replies: 51
Views: 1743

Re: JOric

I think most fairly, it is designed to be memory mapped, but to a CP1610, which has a multiplexed bus. So the extra level of indirection on most machines is implemented just because it's the easiest way of dealing with that.
by ThomH
Thu Mar 29, 2018 6:50 pm
Forum: Emulators
Topic: JOric
Replies: 51
Views: 1743

Re: JOric

Unfortunately I don't think there's a quick shortcut to test disk titles because many of them, if not most, talk to the controller directly. I would dare imagine you can implement your WD to jump directly to any requested sector and stream its bytes exactly as the CPU reads them but the Oric disk fi...
by ThomH
Thu Mar 29, 2018 6:09 pm
Forum: Games
Topic: Wolfenstein / DOOM for Oric : has this been done?
Replies: 15
Views: 821

Re: Wolfenstein / DOOM for Oric : has this been done?

Do you have pointers to what you call run-slice? I assume you are referring to a particular algorithm but a cursory search does not give any useful results. Oh, sorry — it's actually the much lesser-seen Bresenham algorithm. Much easier to derive though: If the target line is (x, y) and, for agumen...
by ThomH
Wed Mar 28, 2018 8:35 pm
Forum: Games
Topic: Wolfenstein / DOOM for Oric : has this been done?
Replies: 15
Views: 821

Re: Wolfenstein / DOOM for Oric : has this been done?

I guess you could use a small window and squeeze a double buffer into text mode, but I guess then you're probably at 64x48 or somewhere around that? I strongly suspect that's the equivalent of what the Vic Doom is doing, from looking at the window size. Otherwise all I can think of is keeping the wa...
by ThomH
Wed Mar 28, 2018 8:03 pm
Forum: Games
Topic: Wolfenstein / DOOM for Oric : has this been done?
Replies: 15
Views: 821

Re: Wolfenstein / DOOM for Oric : has this been done?

Haha, so the amount of time I spent persuading myself that it's really a multiply by cosine rather than a divide was actually a substantial proportion of the original time spent on the demo!

I should spend my time firing up an assembler rather than drawing pictures.
by ThomH
Wed Mar 28, 2018 7:22 pm
Forum: Games
Topic: Wolfenstein / DOOM for Oric : has this been done?
Replies: 15
Views: 821

Re: Wolfenstein / DOOM for Oric : has this been done?

I assume that it's not all that helpful to make the standard recommendations? don't associate angles one-to-one with screen columns — build a table of casting angle per column slice as an offset from the centre ahead of time as a function of atan, because you're solving for the angle inside a right-...
by ThomH
Wed Mar 28, 2018 5:16 pm
Forum: Games
Topic: Wolfenstein / DOOM for Oric : has this been done?
Replies: 15
Views: 821

Re: Wolfenstein / DOOM for Oric : has this been done?

I've not seen one. I definitely think something like that would be easily within the Oric's scope, and as to reproducing Doom in the sense that the other 8-bit versions do, the algorithm isn't even that hard I think: they don't do variable height sectors and the Spectrum Doom in particular is heavil...
by ThomH
Tue Mar 27, 2018 2:56 pm
Forum: Emulators
Topic: Steam/GOG
Replies: 11
Views: 4712

Re: Steam/GOG

That probably raises some questions about the Microdisc ROM, and similarly might lead to the same queries re: the Jasmin or any other disk system you've provided a compatible boot sector for, but it would substantially reduce the list of potentially interested parties. If it definitively removed any...