Search found 69 matches

by ThomH
Wed May 17, 2017 2:11 pm
Forum: Emulators
Topic: Yet Another
Replies: 41
Views: 6475

Re: Yet Another

Hi again; quick drop-in to say that the video issues that presented themselves on a Mac Pro are now resolved. I'd made an error in mapping between buffers such that I was unintentionally relying very heavily on floating point rounding going one way rather than another. So it could easily have surfac...
by ThomH
Tue Feb 21, 2017 8:09 pm
Forum: Technical questions
Topic: Does anybody have the WD1793 data sheet?
Replies: 6
Views: 2100

Re: Does anybody have the WD1793 data sheet?

Do you need a chip? I have a lot of 8877 chips used in the Cumana. They aren't directly compatible and need some different capacitors or something but if you're stuck it might be possible to substitute. Oh, no, but thanks for the offer! It was merely academic interest pursuant of emulation. Sadly I...
by ThomH
Tue Jan 31, 2017 8:26 pm
Forum: Emulators
Topic: Yet Another
Replies: 41
Views: 6475

Re: Yet Another

Not seeing any issues with graphical glitches on my MBPro ... I feel like probably there's a piece of state I'm failing properly to initialise, or something like that. Based on trying the various emulated machines, it's seemingly processing data correctly and outputting it to the right place but pu...
by ThomH
Mon Jan 30, 2017 1:40 pm
Forum: Emulators
Topic: Yet Another
Replies: 41
Views: 6475

Re: Yet Another

I wrote my first emulator on a laptop with something like a Pentium 133 as the main CPU so please don't complain with your highly powered computer... ;-) Good work with the latest release :) I suspect I may have had a Pentium 200 in mine but my point was more: I can't just throw on a Linux virtual ...
by ThomH
Sat Jan 28, 2017 4:20 pm
Forum: Emulators
Topic: Yet Another
Replies: 41
Views: 6475

Re: Yet Another

I wrote my first emulator on a laptop with something like a Pentium 133 as the main CPU so please don't complain with your highly powered computer... ;-) Good work with the latest release :) I suspect I may have had a Pentium 200 in mine but my point was more: I can't just throw on a Linux virtual ...
by ThomH
Sat Jan 28, 2017 4:03 am
Forum: Emulators
Topic: Yet Another
Replies: 41
Views: 6475

Re: Yet Another

Do you have any plan for releasing Windows and Linux versions of the emulator? I definitely want to. I just don't currently have great access to either type of system; I'm developing on a five-year old MacBook Air which means limited everything, including hard disk space. But I've attempted to keep...
by ThomH
Wed Jan 11, 2017 2:54 am
Forum: AY sound chip
Topic: "music" in Xenon meteors noise
Replies: 22
Views: 11085

Re: "music" in Xenon meteors noise

For the record, an example of my emulator's current attempt at AY playback is here and attached in lossless form — it's the opening of Barbitoric (with disk access gaps). The windowing filtering gives some very non-square wave forms such as the below, based on some real maths, so hopefully I'm alrea...
by ThomH
Sun Jan 08, 2017 2:25 am
Forum: AY sound chip
Topic: "music" in Xenon meteors noise
Replies: 22
Views: 11085

Re: "music" in Xenon meteors noise

Obviously an emulator will miss the analog part (filter & so on) that are not impossible to emulate but really time consuming to get something accurate.. Mine has a filter; it creates a wave at the chip's clock rate then performs a windowing filter to reduce it to your computer's sampling rate. But...
by ThomH
Sat Jan 07, 2017 8:16 pm
Forum: AY sound chip
Topic: "music" in Xenon meteors noise
Replies: 22
Views: 11085

Re: "music" in Xenon meteors noise

Obviously an emulator will miss the analog part (filter & so on) that are not impossible to emulate but really time consuming to get something accurate.. Mine has a filter; it creates a wave at the chip's clock rate then performs a windowing filter to reduce it to your computer's sampling rate. But...
by ThomH
Thu Jan 05, 2017 11:10 pm
Forum: AY sound chip
Topic: "music" in Xenon meteors noise
Replies: 22
Views: 11085

Re:

Perhaps a sound signature of the inventor of the AY? Some instructions not listed in the 6502 runs correctly, the engineers hide us something... In fact, it seems related to the way random number are generated. The noise generator is mainly a random function, and since on computer random is never r...
by ThomH
Tue Jan 03, 2017 5:07 pm
Forum: Hardware hacks and extensions
Topic: Announcing... the AtmoStrat !
Replies: 41
Views: 5732

Re: Announcing... the AtmoStrat !

I'm well behind the time but, if it's of any help at all, the only difference you'd need to make in video output to produce interlaced graphics rather than progressive is to ensure that every other vertical sync ends halfway through a horizontal line. So it'd either need a ULA modification or some w...
by ThomH
Tue Jan 03, 2017 1:25 pm
Forum: Tape and floppy disk converters
Topic: Barbitoric has incorrect CRCs?
Replies: 15
Views: 2320

Re: Barbitoric has incorrect CRCs?

Could you check these ones: - http://www.pouet.net/prod.php?which=64343 - http://www.pouet.net/prod.php?which=65688 they will probably fail to, if they do, then it means I probably forgot to call the compute crc somewhere in the FloppyBuilder :) I got: OricTech.dsk: Completed; 84 tracks found, 2856...
by ThomH
Tue Jan 03, 2017 2:18 am
Forum: Tape and floppy disk converters
Topic: Barbitoric has incorrect CRCs?
Replies: 15
Views: 2320

Re: Barbitoric has incorrect CRCs?

Further on this, I'm finding that quite a few of the PC-produced pieces of work that are slightly older have incorrect CRCs but none of the things imported from a real Oric or that are more recent (including 1337 and Space: 1999). I've also filed a bug against Oricutron alleging that it doesn't chec...
by ThomH
Mon Jan 02, 2017 10:45 pm
Forum: Tape and floppy disk converters
Topic: Barbitoric has incorrect CRCs?
Replies: 15
Views: 2320

Re: Barbitoric has incorrect CRCs?

I definitely think that would be an appropriate test. In the meantime, I'll just confirm the testing I've done. You'll see that it prints a little status report on how many CRCs it felt the need to fix after being run. That being the case: 1337.dsk: Completed; 32 tracks found, 1088 CRCs checked, 0 f...
by ThomH
Mon Jan 02, 2017 7:16 pm
Forum: Tape and floppy disk converters
Topic: Track reading (Sedoric / FDC)
Replies: 42
Views: 15793

Re: Track reading (Sedoric / FDC)

Oh! Wait! A distant spark fired, and I remembered the smart solution to two-drive copying. Not originally mine, so no credit due, alas. A common feature of the Oric disk interfaces is to use one controller chip to support multiple drives. But neither of the WD chips used by the Microdisc or the Jasm...