Sony HB-F1XD booting to MSX-DOS issue - Floppy drive light on?

Supporter (8)

14-02-2021, 02:06

Hi folks,

I have a HB-F1XD that was working great last year, until being packed away for a move for a few months. On power up, (with or without the MegaFlashROM inserted) without shift being held down to bypass the floppy drive, it will just boot to a blue screen with no prompt and the FDD in use light will stay on indefinitely. It will boot to BASIC if shift is held, but I can't seem to get anything else beyond that. I can also access the MegaFlashROM menu by holding up.

I'm fairly new to the platform so perhaps there is something obvious I'm missing, but I remember the setup being pretty much fine before being packed away for the move this past fall. Any places I should start troubleshooting?

Thanks so much!

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Par meits

Scribe (6576)

14-02-2021, 03:38

Check if the smd caps on the hic1 board (below the diskdrive) are still in tact. The originals will blow and cause nasty unpredictable situations...

Par WhiteCrow

Supporter (8)

14-02-2021, 03:53

The original leaky ones have been replaced, thankfully!

Par sdsnatcher73

Enlighted (4307)

14-02-2021, 05:47

Sounds like the drive is not connected properly (this usually happens if the cable is turned 180 degrees). Not sure if that is possible inside such tight cases. There may also just be an issue with the drive, these are direct drive models but there may be a capacitor causing issues on the drive.

Par WhiteCrow

Supporter (8)

14-02-2021, 07:28

Yeah, the more I look at it, the more it looks like it's a drive problem. I'm not really using the FDD due to having a MegaFlashROM cart - is there a way to get into MSX-DOS while bypassing the FDD system altogether?

Par sdsnatcher73

Enlighted (4307)

14-02-2021, 07:54

You could replace the mask rom with an eprom where you remove the disk rom, that would disable it permanently.

Par WhiteCrow

Supporter (8)

15-02-2021, 21:50

sdsnatcher73 wrote:

You could replace the mask rom with an eprom where you remove the disk rom, that would disable it permanently.

Any tips on how to work with the mask rom or links to any files? I probably have an eprom of large enough size hanging around, but is there a specific type that is a drop in replacement? I haven't gotten deeply into the technical side of the MSX enough to know the specifics of romhacking for it, but I really appreciate the help so far. Would love to get this going again!

Here's a link to a quick video I made of what it's booting to if that helps - maybe I'm missing something simple.

https://www.youtube.com/watch?v=GWR2hpQy5IY

Par st1mpy

Paladin (947)

15-02-2021, 22:37

Do you have any floppy disks to see if the drive is working?

Par WhiteCrow

Supporter (8)

16-02-2021, 05:00

st1mpy wrote:

Do you have any floppy disks to see if the drive is working?

Yep, I tried both to boot off a floppy in the original drive, and I even removed the FDD and connected a known working Gotek FDD to USB which gave the same result.

Par sdsnatcher73

Enlighted (4307)

16-02-2021, 06:30

Okay, from this thread, which is about a 2+ upgrade for the F1XD but has some detail about the ROM, we can learn:

The mask ROM inside the XD is 128kB or 1Mbit in size
Only 64kB is used
It is pin compatible with 27C512 (64kB)
The order of the content is Main BIOS, Sub BIOS, BDOS

So if you burn a 27C512 with an MSX2 Main BIOS and Sub BIOS only (leave the last 16kB all FF). If I may suggest you could use FRS’s msx2newdrv BIOS as it has some nice improvements.

Par sdsnatcher73

Enlighted (4307)

16-02-2021, 08:10

Oh to be clear, the 27C512 does not have the exact same pinout as the mask ROM but the differences are negligible (for details check the mentioned thread) and for the use case in the F1XD it will work as a drop in replacement.