HIC-1 board redesign and improvement | MSX Resource Center (Page 7/8)

By Wierzbowsky

Guardian (3648)

25-05-2022, 20:06

Glad to hear! Did you also test the tape loading/saving? Does the sound work as intended?

By Wierzbowsky

Guardian (3648)

28-05-2022, 16:50

Has anyone else succeeded in building the HIC board kit and installing it into your MSX? Does all functionality work as intended? As I said earlier, the project it not going to be public unless I know that my HIC redesign is confirmed to be working.

By Warchild

Paragon (1298)

28-05-2022, 17:52

Hi Alexey, I’ve not installed the HIC board yet. It’s expected to be done this summer with help of a friend (he lives far from me so we’ll meet on holidays). I’m sorry it will take some time.

By vaj_Lehenak

Champion (352)

03-06-2022, 19:25

Hello, sorry for the wait.

The sound also works very well, the tape I can't test it.

thank you very much

By Wierzbowsky

Guardian (3648)

14-08-2022, 17:11

The files for the HIC board v1.0 project are now released into the RBSC's repository for non-commercial use. For commercial production licensing please contact me by mail. The repository can be found here:

https://github.com/RBSC/HIC_Board

By sdsnatcher73

Enlighted (4298)

14-08-2022, 20:30

Cool! Great job Alexey. My A1F is working very well with this board (although I believe it is a slightly earlier version )

By Wierzbowsky

Guardian (3648)

14-08-2022, 22:03

sdsnatcher73 wrote:

Cool! Great job Alexey. My A1F is working very well with this board (although I believe it is a slightly earlier version )

Your board is functionally identical to the one that I released to the public with the only exception - it has HC04 chip instead of the original 4069UBF. Which proves that the dependency on the original 4069 chips no longer exists.

By Jipe

Paragon (1625)

18-09-2023, 18:53

there is a problem with this card made by RBSC with the FM sound of the HB-F1XDJ
it saturates the sound of PSG
in the original HIC of the HB-F1XDJ the 0 ohm resistor on the pin 18 input is replaced by a 220 k to adapt the sound level
this resistance does not exist on the HIC of RBSC the signal is shunted directly
to correct the problem you must unsolder the shunt on R14 in the MSX and replace it with a 220 K resistor

thank you to the members of rbsc for correcting their circuit and implementing this 0 ohm resistor in their HIC

By Wierzbowsky

Guardian (3648)

18-09-2023, 20:59

After comparing to 2 original schematics I've indeed found an error in my board:

For some reason the bug was only found after testing on F1XDJ. On a few other machines it worked just fine. The fix of the existing board is easy - replace C20 with 39pF, cut one trace and connect 2 pads:

@Jipe, will this fix the problem?

By Jipe

Paragon (1625)

19-09-2023, 07:10

C20 is not the problem
on a MSX2+ the pin 18 is a input for FM sound chip YM2413
you miss HIC_J2 on your board on the wire of RESI
HIC_J2 is a resistor with value 224 (220k) on the HIC for HB-F1XDJ