exxos's Atari, Amiga & retro forum

I fitted the board to my testing machine and powered on, having done the track cutting patches, but re-reading the forum, I have questions!!
First things first, I just realised that I'm an idiot, because the ROM I ordered a while back for the STF remake, which I was going to use, seems to actually be a TOS 1.02/1.04 ROM going by my receipt. My fault entirely, an error in ordering, but I will at least be able to use it in one of my STFMs somewhere down the road.

Annoyingly, I'm in the same boat as PhilC, I have a TL866II+ and it also shows the 27C4096 as a 40PIN DIL package, and although I have a PLCC to DIL adapter, it doesn't detect the chip. Speaking to exxos it could be the PLCC-DIL adapter doesn't have the power rails connected, so I need to look into that. Doubly annoying is that I have 2 blank 27c4096 chips sat waiting to be programmed! If only I could program them with the images I needed!!!!

I was able to intermittently get it to boot to TOS 1.02, but since the machine has 1.02 installed, I couldn't tell which ROM was in use. I removed the ROM from the IDE board and can get it to boot to the onboard TOS. I did wonder though, does the onboard ROM need to be removed, or is it like with my PAK 68/20 and it doesn't care about onboard ROM and just uses it's own?

I guess the question this brings up, is out of the on board jumpers, is there a guide as to what they are all for, and what should be set please? For example, what is the purpose of select 1 and select 2? What do the jumpers at JP2 do?

Also, the patch that shows the 2 jumpers next to the TOS selector with a cap and resistor connected, is this mandatory? I ask as had no time tonight to do anything other than the track cuts and bodge wires.

I guess I'd better get the ROM sorted first!! Ordered!! Lets see what difference that makes!

The motherboard ROM needs to be removed..

There are no jumpers other than the ROM select one...

And yes the jumpers as icky had them with cap and resistor are needed.. And have to be the exact values as stated.

Tos 104 will work, but Autoboot only works with 206. So you would have to install the driver on floppy and boot from there if using 104.

BTW.. 104 has the rainbow effect Fuji in desktop info...102 its just black.

rubber_jonnie wrote: 10 Apr 2019 22:53
Annoyingly, I'm in the same boat as PhilC, I have a TL866II+ and it also shows the 27C4096 as a 40PIN DIL package, and although I have a PLCC to DIL adapter, it doesn't detect the chip. Speaking to exxos it could be the PLCC-DIL adapter doesn't have the power rails connected, so I need to look into that. Doubly annoying is that I have 2 blank 27c4096 chips sat waiting to be programmed! If only I could program them with the images I needed!!!!

RJ, when we build the ExxosAtari I made the adapter from an eBay dip to plcc adapter purchase. As I recall all the pins were correct except 2. Look at the attached pic and match the 44 PLCC pin names to the dip pin names. I believe all was correct except for 2 wires I had to add.

Cool thanks I will have a look at that.

No plans on using the accelerator for the disk tests. Will have 245's tomorrow and some IDE adaptors and plugin devices Saturday too Monday.

I had the same issue recently with my ROM programmer and the PLCC to DIL adapters. The connections from the DIL pins have 2 pins wired to NC pins on the PLCC socket!

You need a couple of bodge wires to connect the PLCC socket pins together:

PLCC pins 12 and 13 need connecting together and pins 33 and 34 need connecting.

Once I made these changes I was able to program 27c4096 PLCC chips.

Thanks for the advice on the Rom adaptors guys, will do that later today.

If one of you guys is interested there is the HDD / FDD keyboard LED circuit that exxos came up with.

https://www.exxosforum.co.uk/forum/viewt ... =90#p19026

It's untested and as discussed with exxos may need a different mosfet to get it to work. Time to break out the breadboard or some other hackery :)

To connect this to the board the following pins are assigned on the header.

JP2_PIN11 is Keyboard LED - Line out to exxos' LED circuit
JP2_PIN12 is ST LED - Line in from the FDD line on the keyboard connector on the ST motherboard (Pin 3)

exxos wrote: 10 Apr 2019 23:08 The motherboard ROM needs to be removed..

There are no jumpers other than the ROM select one...

And yes the jumpers as icky had them with cap and resistor are needed.. And have to be the exact values as stated.

Tos 104 will work, but Autoboot only works with 206. So you would have to install the driver on floppy and boot from there if using 104.

BTW.. 104 has the rainbow effect Fuji in desktop info...102 its just black.

Cool, thanks. I think my test mobo has soldered in ROM, so will have to work out whether or not I remove it, or go to another board with socketed roms. I'll get the resistor/caps done on the select jumpers too.

I've ordered the correct ROM from you, so I'll look again when I get that.

Icky wrote: 11 Apr 2019 08:28 If one of you guys is interested there is the HDD / FDD keyboard LED circuit that exxos came up with.

https://www.exxosforum.co.uk/forum/viewt ... =90#p19026

It's untested and as discussed with exxos may need a different mosfet to get it to work. Time to break out the breadboard or some other hackery :)

I did spend ages looking for a MOSFET, and I found one, added it to my Farnell order which has normal lost the basket and I forgot about it then.

I have ordered and got some other MOSFETs but I think they were for a different project.. I need to check.. But basically these are SOT23 type packages so a small PCB would have to be done first.. And they have a look on Amazon and and see if I can find a breakout board for it..

Do not use the MOSFET in my simulation circuit! As that circuit is literally just that, simulation circuit not a actual circuit so do not build it with those parts!