Nice to see another Queensland local on the forum.

I have soldered PAD1 to IC5 pin 19 and same results. No floppy and no SatanDisk. As I said the inverter chip is working as far as I can see and sending 0v to IC6 pin 19. AAEAEC27-0CC4-400C-A605-D04C60CE78D6.jpeg I will try this on my other H4 tomorrow and see if I get the same result or not. Time fo...

Can I confirm which way the inverter is expected to work. Looking at the SN74LVC1G04 pinouts, the feed from PAD1(FDCS) is the input and the inverted output is sent to IC6 pin 19.

So the 5v from GAL pin 7 to PAD1 shows 5v and thus IC6 pin 19 is 0v. It looks like the inverter is working correctly?

PAD1 is not shorted to GND. Have checked both in the H4 and out.

I have double-checked my soldering on the fix PCB and everything looks fine but the fix PCB stops both floppy and SatanDisk working when installed in my H4. Some testing with my multimeter. With PAD1 disconnected from the GAL pin 7, I see 5v on IC6 pin 19 (HDCS), 0v on PAD1 on the fix PCB and 5v on ...

Okay have the DMA Buffer fix PCB installed and PAD1 is connected to pin 7 (FDCS) on the 1.44mb GAL socket. I have EmuTOS running, my SatanDisk in and powered from 12v on one of the 4 pin power headers. SatanDisk works and floppy both work fine with the IC6 jumpers in place prior to testing this fix ...

exxos wrote: ↑

Mon Jan 20, 2020 9:56 am

It goes to FDCS on the DMA.

Thanks for confirming. Pin 7 on the 1.44mb GAL is labelled as FDCS in the schematic so this looks as good a place as any to connect to. Will give it a go.

Okay back to the DMA H4 Buffer fix PCB. I now have one assembled and ready to test. Can someone confirm where the PAD1 on the fix PCB connects to on the H4 board? Does it connect to the 1.44mb GAL socket pin 7 (as per @Icky inverted IC bodge)?

Okay, programmed HN27C4096G chip is working as dual boot TOS 1.04/EmuTOS 0.9.12. Some initial shots on my H4: 714844C7-5F7B-4F64-B8C1-029F062C025E.jpeg ECA7554D-D26A-4194-AC49-8291F3F6EB28.jpeg F8F144A8-FD01-4BE6-8972-3525016EB8A6.jpeg Interestingly the RTC date is way out under EmuTOS showing 1990....

I was thinking to try EmuTOS on one of my boards but I have no idea how to convert the IMG to work in a 27C4096 ROM chip. The plan was to replace TOS 1.02 in the dual boot ROM chip. I have downloaded the 192kb EmuTOS IMG file but when I open it in my ROM programmer the bytes look to be swapped aroun...