Vhd interface for victor hc90/95

Page 12/13
5 | 6 | 7 | 8 | 9 | 10 | 11 | | 13

By popolon_

Champion (310)

popolon_'s picture

09-12-2022, 18:05

In HC-95 schematics (in msxpro web site) there is pinouts for 96-pin slot, but pinout numbers for all three lines (a,b,c) are in wrong order, shuold be other way around (from up to down: 32 ... 1). Also it seems MSX slot picture has pinout numbers mirrored (left <-> right).

But the real question is about JVCREQ signal. Because there is drawns JVCREQ signal as only pull up resistor to +5V, so constant high signal if the connected card in 96-pin slot does not alter it. So card will set it, and not HC-95 side? If that is right, then why this VHD card only reads this JVCREQ signal as input signal? It reads the signal in case there would be some other card that would set his JVCREQ as low, and then this VHD card needs whole address (0xFFBC- 0xFFBF) to access VHD ports . But when standalone (or other card do not set the JVCREQ to low), then this VHD card needs only I/O address (0xBC- 0xBF) to access VHD ports. So what is the point to have this differentiation?

By gdx

Enlighted (5997)

gdx's picture

11-12-2022, 11:07

I don't know. I just guess JVCREQ and JVCACK are also active low as BUSREQ and BUSACK.

By popolon_

Champion (310)

popolon_'s picture

13-12-2022, 21:44

now i updated the pcb with the missing reset line also to github: https://github.com/popolonx/MSX_STUFF/tree/main/vhd_c9d_card

By popolon_

Champion (310)

popolon_'s picture

05-01-2023, 15:45

Now that pcbs arrived, i can try what happens when IF-C9D is plugged to Victor HC-7 cartridge port...

IMG_20230105_1640519612.jpg

By popolon_

Champion (310)

popolon_'s picture

07-01-2023, 12:09

VP commands seems to work in Victor HC-7 cartridge slot with IF-C9D connected via adapter.

IMG_20230107_1257052532.jpg
IMG_20230107_1256500062.jpg
IMG_20230107_1259598102.jpg
IMG_20230107_1300106362.jpg

By matten

Supporter (4)

matten's picture

10-01-2023, 02:32

That 's amazing Popolon_ !
I am the buyer of the auction with the Sharp X1 interface in 2022 https://www.remambo.jp/auction/item/g1057073564#photo
So far i have 3 VHD games:
Time gal MSX (i dumped the audio cassette on archive.org)
Road Blaster sharp X1 ((i dumped the audio cassette on archive.org))
Thunder Storm (i have the version with just the movie vhd, no software included)
Do you have any vhd cassette tape you can also dump on archive.org for the community and the future please?
I have everything to play Sharp X1 Vhd so far.
For Msx i only lack the interface like everybody!

By popolon_

Champion (310)

popolon_'s picture

10-01-2023, 08:31

Yes, i have Thunder storm cassette for MSX and X1. And VHD interpreter cassette for X1. But i do not have that X1 side interface(tried to bid to that same auction...), only Sharp VHD X10B player. Can you matten take photos inside that VO-20PC unit? As one dream is to also replicate that X1 side interfaces. And then upload the cassettes...

By gdx

Enlighted (5997)

gdx's picture

10-01-2023, 09:46

Is it the CAS or WAV format? I looking for the CAS files.

By popolon_

Champion (310)

popolon_'s picture

13-01-2023, 18:15

Now i also made initial cartridge version schematics and pcb based on C9D card:
https://github.com/popolonx/MSX_STUFF/tree/main/vdh_cartridg...

By popolon_

Champion (310)

popolon_'s picture

27-01-2023, 08:56

Now cartridge pcb arrived.
IMG_20230127_0901040242.jpg

If only somebody could dump the rom from IF-7900 cartridge, so we could get the whole VHD basic. And to get pictures from inside about the PCB. After that the missing interface to read program data from VHD disk would be easier.
However I am not holding my breath to get any pictures inside that IF-7900...

Page 12/13
5 | 6 | 7 | 8 | 9 | 10 | 11 | | 13