Recent content by ejona

Looking at the board in a brochure, the board may be simple enough to reverse engineer from good picture of the front and back, where we can make out the chip markings. From the picture on the brochure, it looks like it uses I/O and interrupts to communicate with the CPU. In the center of this...

@retrobecanes, the first post of the thread is still mostly accurate. The main adjustment is how to produce an image. Options: Current versions of my HFE converters are at https://ejona.ersoft.org/files/floppy/ . I have an NSI converter there. This has been confirmed working...

I've made copies of the original key. PM me to mail you one.

@abzman, the exidy sorcerer looks to use the standard Micropolis format, so the format is the same as the Vector Graphic with VGI files. The only difference for the .dsk is it does not include the (added-later) ECC bytes, which would have just been zero. So instead of the raw sectors being 275...

@abzman, that was helpful for the format. I've added a pm2hfe.py to https://ejona.ersoft.org/files/floppy/ . I have nothing to test it against, so if it doesn't work just go with the original approach using pc2flop and we'll debug it later. If you know of any similar documentation for the DSDD...

@abzman, you'd just need to use a 10 hard sector HFE image. Single density and double density use the same file type for HFEv3. And there's not any real advantage to single-sided HFE. I've attached some blank disks created by mk_hfe.py (10 and 16 sector, 40 and 80 track). Either of the 10 sector...

snhirsch mentioned on the HxC forum a long time ago that it was a logical/software interleaving, so it wouldn't show up in sector headers. And I don't think it would have been documented in the manuals I was looking at.

There was another report of successful FlashFloppy usage with Northstar Advantage, which also included writing. So the main issue was just the small pulse misalignment in HxCFloppyEmulator. So we've seen two successful FlashFloppy usages on each of the Northstar MDS-A-D and Vector Graphic...

I shared my NSI index finding with Jeff, and he's posted a new version of HxCFloppyEmulator with fixed index pulses.

The sound chip is a SN76489 (top-left of schematic). The chip is on ports 18h/19h. A note configuration table is at the end of the programmer's guide. Deramp has a Vector 4 Demo (bootable) disk that includes a nice music demo. My vector-demo (non-bootable) disk does use the speaker in the...

Yeah, I have a good key. I know I have an good original key, but I won't be near it for some weeks. I don't remember the precise state of the keys near me; I think I have a good copy made decades ago.

I expect it is highly similar to the Vector 4. The case and back ports are identical. It uses 96 TPI floppies instead of the 100 TPI that the Vector 4 uses. That would make it similar to the Vector 4-S, which I've not seen much information about, as it was a very late in Vector Graphic's...

I've fixed nsi2hfe's track ordering for the second side. I've put the updated nsi2hfe.py at https://ejona.ersoft.org/files/floppy/ so there's fewer versions floating around. It always uses 0xFB as the second sync byte and has no interleaving. As I mention on the Horizon vs. Advantage thread...

https://deramp.com/downloads/north_star/software/h_harte_disks/HD-18.zip has FluxEngine recordings of three disks: Single_Retry_Test_C2_C3_02-05-83. DSDD. 349 µs wait before preamble. track/head/sector sync byte, using physical track number. No interleaving...

@shirsch's notes seem to be for the Advantage (especially with the note of inconsistent docs). I was digging into the formats for the Northstar single-density controller on the FlashFloppy thread. Interleaved sectors are a pretty big difference with the Advantage, although I don't see that...