exxos's Atari, Amiga & retro forum

So I obviously got confused with those 3 Hsync lines :(

The fix is simple to do.. Lift pin 8 out of the socket on the LS04 U51 (or cut it off) .. and wire link on the bottom of the socket pins 8 & 9... so that will bypass that inverter...

Its going to a while before I get all the parts together to build my board.. still waiting for the board to make the trip across the pond and parts I have ordered. So if processor signals look good I think I would plug in the diagnostic cartridge and a 9600 baud terminal (terminal emulator) to the serial port. There's a better chance to get a meaningful interaction out of the serial port. Do not need board video or keyboard to have an a interaction. Big issue would be if a good serial setup was present in the 6850. Just a thought.. :D

But the serial port has had a total re-design, it hasn't been tested either :)

And the serial port on the ST is done by the MFP, not the ACIA (they are use for MIDI and Keyboard).

I've boxed up my board and bits to send off tomorrow for assembly.. Don't really know how long that will take, maybe a couple of weeks I guess..

I guess we really need to see if someone else as this video sync fault or not.. I mean really even a broken system should still output stable video frame..

Will do the video mod soon, I did notice that there were two inverted signals on the monitor port but then we had a power cut, so didnt get a chance to note which ones.

I did see 15Khz and 60Khz out of the Glue.

Hopefully have more time later on or tomorrow.

Forgottenmyname wrote: 17 Sep 2018 18:55 Will do the video mod soon, I did notice that there were two inverted signals on the monitor port but then we had a power cut, so didnt get a chance to note which ones.

I did see 15Khz and 60Khz out of the Glue.

The inverters are not actually used (well shouldn't be) there were for the modulator... just I didn't notice there was 3 HSYNC signals going on.. but the monitor port goes syncs go direct to the GLUE without buffering... so I might actually add buffers on those on a later revision (if it doesn't break something that is).

All other signals come from the shifter directly.. so monitor output should be good.. at least it has a black screen and white border, so looks like the RGB buffers I re-designed are working.. so that is at least something...

Forgottenmyname wrote: 17 Sep 2018 18:55 I did see 15Khz and 60Khz out of the Glue.

Assuming you have a PAL TOS, that means TOS didn't execute and/or the machine is being kept in RESET. One of the first things it does is to set 50Hz.

It does mean GLUE is working as it should :D

troed wrote: 17 Sep 2018 19:28

Forgottenmyname wrote: 17 Sep 2018 18:55 I did see 15Khz and 60Khz out of the Glue.

Assuming you have a PAL TOS, that means TOS didn't execute and/or the machine is being kept in RESET. One of the first things it does is to set 50Hz.

It does mean GLUE is working as it should :D

That is a good point actually... I sent out PAL versions of the ROM.. Peoples monitors really need to support 50 & 60Hz.. mine does :P

I'm checking around the video and don't see any other mistakes anywhere..

See, I learn something new every time I turn this board on, which is one of the reasons I got it 8-)