Search found 238 matches
- Wed Jan 22, 2020 11:46 pm
- Forum: Technical questions
- Topic: Jasmin time
- Replies: 33
- Views: 24568
Re: Jasmin time
Have you tested the clock signal on the Jasmin? Just as a random guess, but has it possibly drifted into overclocking territory? That'd directly affect the speed it wanted data when writing, but might not be sufficiently far to cause an issue when reading. I guess you could also read track after wri...
- Wed Jan 22, 2020 7:14 pm
- Forum: General Discussion
- Topic: New Guy here from USA
- Replies: 14
- Views: 7769
Re: New Guy here from USA
If you can handle either Bulgarian or ROM swapping (is it socketed?), don't rule out the Pravetz 8D. It seems to be much more readily available than the Atmos, and cheaper too. It's a full Oric clone, with no hardware differences documented that I'm aware of. Right now I see six for a search on ebay...
- Wed Jan 22, 2020 3:58 am
- Forum: General Discussion
- Topic: New Guy here from USA
- Replies: 14
- Views: 7769
Re: New Guy here from USA
I'm an ex-pat, so it counts for less, but that makes at least two of us in the USA. I am located in Northern California... and you? TJ I was in the Bay Area when I first moved over, but nowadays I'm in New York. So on the one hand I sort of miss it during winter, but on the other I enjoy actually h...
- Tue Jan 21, 2020 9:34 pm
- Forum: General Discussion
- Topic: New Guy here from USA
- Replies: 14
- Views: 7769
Re: New Guy here from USA
I'm an ex-pat, so it counts for less, but that makes at least two of us in the USA.
- Sun Jan 19, 2020 4:18 am
- Forum: General Discussion
- Topic: SCSI harddrives...
- Replies: 7
- Views: 4957
Re: SCSI harddrives...
If it's any help, SCSI command 4 is 'format unit' but the ECMA spec explicitly says: "The FORMAT UNIT command ensures that the medium is formatted so that all data blocks can be accessed. There is no guarantee that the medium has or has not been altered." So to my reading, an individual SC...
- Fri Jan 17, 2020 3:53 pm
- Forum: Emulators
- Topic: Clock Signal — an Oric emulator for macOS and Linux
- Replies: 170
- Views: 159070
Re: Clock Signal — an Oric emulator for macOS and Linux
actually, follow-up query on the Jasmin: if you can select arbitrarily many then how do you deselect drives? Drive 0 -> 0x3FC, Drive 1->0x3FD, Drive 2->0x3FE, Drive 3->0x3FF To select a drive write 1 to the corresponding address and 0 to deselect. Cool, thanks! I'm going to hold back on iss's sugge...
- Fri Jan 17, 2020 4:53 am
- Forum: Emulators
- Topic: Clock Signal — an Oric emulator for macOS and Linux
- Replies: 170
- Views: 159070
Re: Clock Signal — an Oric emulator for macOS and Linux
Most importantly: the BD-DOS spin-down issue is 'fixed' (in the sense: I've taken a different guess at the sort of RDY it's expecting from the drive) in a new release . Otherwise: Sync 60Hz is out of sync because it is genuinely out of sync. The simulated Oric produces a real 1d video signal with ap...
- Fri Jan 17, 2020 4:01 am
- Forum: Operating systems, utilities and other serious software
- Topic: Is BD-DOS lost to time?
- Replies: 94
- Views: 66745
Re: Is BD-DOS lost to time?
Some more quick observations on this, relevant to yesterday's botched release: The boot ROM performs: seek to 0, read boot sector, check for errors (including drive not ready). Somewhere between then and the command prompt, the logic changes to: (i) issue a force interrupt and check for drive not re...
- Thu Jan 16, 2020 6:15 am
- Forum: Emulators
- Topic: Clock Signal — an Oric emulator for macOS and Linux
- Replies: 170
- Views: 159070
Re: Clock Signal — an Oric emulator for macOS and Linux
It's late in the day, so I'll be quick: I've uploaded a new release that takes a shot at Byte Drive 500 emulation. EDIT: it appears there’s a dangling bug with drive spin-up on the Byte Drive; it’ll happen the first time but not subsequently. Either issue all of your DOS commands really quickly, bef...
- Thu Jan 16, 2020 4:59 am
- Forum: Operating systems, utilities and other serious software
- Topic: Is BD-DOS lost to time?
- Replies: 94
- Views: 66745
Re: Is BD-DOS lost to time?
Further notes, probably the final for today: The boot sector accesses $0311 and $0317 only. It has a check for BASIC 1.0 (at 04a5–04aa in the disassembly above). Therefore either $0311 or $0317 must disable the disk ROM, and the other must do something else. It seems safe to respond to either and ig...
- Thu Jan 16, 2020 2:37 am
- Forum: Operating systems, utilities and other serious software
- Topic: Is BD-DOS lost to time?
- Replies: 94
- Views: 66745
Re: Is BD-DOS lost to time?
Fabrice's notes are a little vague on what accesses other than to the WD do (at least when read through automated translation), so I am brute-forcing the problem, with slightly weird results. Per Fabrice, the accesses other than to the WD are probably to Apple/Pravetz-esque soft switches. I seemed t...
- Tue Jan 14, 2020 11:36 pm
- Forum: Operating systems, utilities and other serious software
- Topic: Is BD-DOS lost to time?
- Replies: 94
- Views: 66745
Re: Is BD-DOS lost to time?
Fantastic, amazing! I'm sure we can figure it out from the ROM and a disk image. Given that the intention of the Byte Disk was to be the disk drive for every platform, showing only the relevant files on each, it might also be fun to try to figure out the on-disk format. There's possibly non-Oric ver...
- Tue Jan 14, 2020 9:18 pm
- Forum: Operating systems, utilities and other serious software
- Topic: Is BD-DOS lost to time?
- Replies: 94
- Views: 66745
Re: Is BD-DOS lost to time?
Probably the actual easiest thing for answering these sort of questions for myself would be to learn French.
Pulling on that thread there seem to be articles in both CEO-Mag #154 and 155. So a quick subscription to that is probably the best plan.
Pulling on that thread there seem to be articles in both CEO-Mag #154 and 155. So a quick subscription to that is probably the best plan.
- Tue Jan 14, 2020 4:11 pm
- Forum: Operating systems, utilities and other serious software
- Topic: Is BD-DOS lost to time?
- Replies: 94
- Views: 66745
Is BD-DOS lost to time?
BD-DOS, for the Byte Drive 500, is mentioned on the Wikipedia Oric page and reported on non-Oric forums as though it were primarily an Oric device. It appears in photographic form in CEO-Mag #272.
Has anyone preserved BD-DOS and/or any technical information for potential emulation?
Has anyone preserved BD-DOS and/or any technical information for potential emulation?
- Mon Jan 13, 2020 4:56 pm
- Forum: Tape and floppy disk converters
- Topic: Track reading (Sedoric / FDC)
- Replies: 62
- Views: 69621
Re: Track reading (Sedoric / FDC)
I've just discovered possibly the most egregious of false sync situations: On track 41, the ID mark for any normally-written floppy will be [sync] A1 * 3, FB 29. The final nine bits of that sequence are 000101001, which MFM encodes to: 01 01 00 10 00 10 01 00 1x, i.e. the C2 sync followed by 00 1x. ...