BASIC audio files for testing

[Mark]

The tones sound great.

If you play back the 2-tone audio sample you made into the OSI you should see hi & lo coming from pin 5 U63 7474 (rxData).
R57 (near the edge connector) adjusts the center frequency for the tone decoder, if it is cranked too far it will always output 1's or 0's I think.

One reason you are not receiving input could be the ACIA clock is wrong due to the 600 baud mod. You should have a 4800Hz ACIA clock on ACIA pin 3 & 4. (300 baud).

Otherwise ensure U63 pin 5 has a connection to RxData on ACIA.
If you are getting no activity in the audio decoder, check to see if the signal is getting through the op-amp...

[Sideburn]

The tones sound great.

If you play back the 2-tone audio sample you made into the OSI you should see hi & lo coming from pin 5 U63 7474 (rxData).
R57 (near the edge connector) adjusts the center frequency for the tone decoder, if it is cranked too far it will always output 1's or 0's I think.

One reason you are not receiving input could be the ACIA clock is wrong due to the 600 baud mod. You should have a 4800Hz ACIA clock on ACIA pin 3 & 4. (300 baud).

Otherwise ensure U63 pin 5 has a connection to RxData on ACIA.
If you are getting no activity in the audio decoder, check to see if the signal is getting through the op-amp...

Thanks. I was combing through the schematics and was thinking I could put the O'scope on U63 pin 5. I will check these. So it is ok that I do not have a U68 or U67 on the board?

[Sideburn]

OK I am getting closer. U63 Pin 5 is good.. I see High low on scope when playing the hilo.wav

pin 2 of U14 has nothing but when i probe it with the scope I get random characters on the screen.

[Sideburn]

Awesome. I got it working by jumping a wire from U14 pin 2 to U63 pin 5..

"REM Hello World" is dumping down the screen from your audio file

Now I need to figure out why there's no trace going to the ACIA ...

** UPDATE: found the cut trace breaking the connection. Good as new now this board is fully functional.

Thanks for all the help!

-Tavis

[Sideburn]

So I have been trying out the games on your page https://osi.marks-lab.com/software/games.html and I can get a lot to load but unfortunately since I've got that 48 column mod they all come up with the screen split up!

I wonder how much work it would be to put a toggle switch on the board to switch between standard 24 and 48 column...

[bxdanny]

Sideburn,

I put together a ROM image that will let you switch between 24- and 48-character modes with a switch. It would need to be burned to a 2716 EPROM, and the appropriate change(s) made to the board to use that instead of the 2316B masked ROM. (But I guess those were already made if the board starts up in 48-character mode.) Then, the A10 signal to the ROM (pin 19) would need to be disconnected from the system A10 line and connected instead to the switch. You could either use an SPDT switch to connect it to either +5V or ground, or add a pull-up resistor to +5V and just use an SPST switch to ground the pin when desired. Either way, a low on pin 19 will select 24-character mode, and a high will select 48-character mode. To switch modes, flip the switch and hit <Break>.

I am also attaching a ZIP file with a couple of non-trivial programs in KCS .WAV format that will work in either mode, one of them being a game.

Mark,

I am wondering why you made the OSIKCS program use the 22,050 sampling rate (1/2 CD rate), when it would have been possible to use 24,000 and have it match the KCS frequencies. I decided to see if I could make a program that would produce 24,000 samples/second .WAV files from BASIC program listings, and I was able to do it, and used that to produce the files in the attached ZIP. I verified that OSIKCS decodes them back to files identical to the ones they were created from, and I presume that the circuitry on the 600 board will do likewise.

[Sideburn]

Sideburn,

I put together a ROM image that will let you switch between 24- and 48-character modes with a switch. It would need to be burned to a 2716 EPROM, and the appropriate change(s) made to the board to use that instead of the 2316B masked ROM. (But I guess those were already made if the board starts up in 48-character mode.) Then, the A10 signal to the ROM (pin 19) would need to be disconnected from the system A10 line and connected instead to the switch. You could either use an SPDT switch to connect it to either +5V or ground, or add a pull-up resistor to +5V and just use an SPST switch to ground the pin when desired. Either way, a low on pin 19 will select 24-character mode, and a high will select 48-character mode. To switch modes, flip the switch and hit <Break>.

I am also attaching a ZIP file with a couple of non-trivial programs in KCS .WAV format that will work in either mode, one of them being a game.

Mark,

I am wondering why you made the OSIKCS program use the 22,050 sampling rate (1/2 CD rate), when it would have been possible to use 24,000 and have it match the KCS frequencies. I decided to see if I could make a program that would produce 24,000 samples/second .WAV files from BASIC program listings, and I was able to do it, and used that to produce the files in the attached ZIP. I verified that OSIKCS decodes them back to files identical to the ones they were created from, and I presume that the circuitry on the 600 board will do likewise.

Wow that’s awesome! I will put this together tonight. You had already made me a ROM to do 48c for me in my initial repair thread here: viewtopic.php?f=3&t=861&start=10 so my board is already set and using a 2716

When I got it it had a 2708 and I think the problem was I needed to supply 12v to the eprom. In the end it was a change for the better regardless.

I will do a 10k pull-up and then use a push on push off button to toggle it to GND.

* when I used OSIKCS tool I have to use the -B option to add nulls.

Thanks, can’t wait to try it!

[Sideburn]

Sideburn,

I put together a ROM image that will let you switch between 24- and 48-character modes with a switch. It would need to be burned to a 2716 EPROM, and the appropriate change(s) made to the board to use that instead of the 2316B masked ROM. (But I guess those were already made if the board starts up in 48-character mode.) Then, the A10 signal to the ROM (pin 19) would need to be disconnected from the system A10 line and connected instead to the switch. You could either use an SPDT switch to connect it to either +5V or ground, or add a pull-up resistor to +5V and just use an SPST switch to ground the pin when desired. Either way, a low on pin 19 will select 24-character mode, and a high will select 48-character mode. To switch modes, flip the switch and hit <Break>.

I swapped my current rom (the one you gave me: syn600-48c2k.rom) that I am already pulling pin 19 high with this new one and the screen is vertically split. Do I need to do something else? Your other rom is working perfectly. See photo:

IMG_7800.jpeg (1.35 MiB) Viewed 177 times

When pin 19 is low, the prompt is on the right:

IMG_7802.jpeg (1.69 MiB) Viewed 175 times

[bxdanny]

Oops, I forgot that yours was the system with the 2k of video RAM. You'd better put back the previous ROM for now.

I'm not sure what you would want the switch to do. No, one switch will not undo the entire video mod. In general, you'd be better off using the C4P version of games that come in C1P and C4P versions. If they don't read the keyboard directly, they will work. If they do, the keyboard-reading parts will still likely be easier to modify than the screen-writing parts of the C1P versions.

[Sideburn]

Oops, I forgot that yours was the system with the 2k of video RAM. You'd better put back the previous ROM for now.

I'm not sure what you would want the switch to do. No, one switch will not undo the entire video mod. In general, you'd be better off using the C4P version of games that come in C1P and C4P versions. If they don't read the keyboard directly, they will work. If they do, the keyboard-reading parts will still likely be easier to modify than the screen-writing parts of the C1P versions.

Ahh ok, I will try some C4P files. When I put the the previous ROM back in I noticed that it doesn't seem to matter whether I pull A10 high or low. Does that make sense?