exxos's Atari, Amiga & retro forum

After a long battle with this booster, I gave up with it about a year ago. All variations of the 2.X series I abandoned..

Though I had some time tonight, so I have been trying some routing variations with no luck. Issue is as before, 6 layer pcbs = huge costs. Setup charges for 2 layer is <£10, 4 layer £30, 6 layer £123... routing the board on 4 layers is just impossible.

So I thought to remove the onboard ROM as its using the whole data bus and most address bus pins, aka lots of routing along with the cpu.. My STFM ROM board could be used instead... its another pcb, but overall will work out cheaper than a 6 layer PCB.

Also the horrid PLCC socket for the CPU is gone...

Only a very quick draft.. stuff needs moving etc etc etc yet... Overall the PCB can be made smaller, as its 4 layers then thats a huge advantage.


I will need to spend some time to get it to route, but So far only 4 airwires left.. so it's very close....

Very nice Exxos, no issues with having a separate rom card. Under this configuration though will it be possible to have the decoding needed for 2.06?

PaulJ wrote: 23 Oct 2018 23:34 Very nice Exxos, no issues with having a separate rom card. Under this configuration though will it be possible to have the decoding needed for 2.06?

The 206 decoding is done in 2 of the 3 GAL's on the booster board. It will need 1 wire to go to the new ROM board (will design a new one) to bypass the GLUE's ROM chip enable. Easy enough.

exxos wrote: 23 Oct 2018 23:39

PaulJ wrote: 23 Oct 2018 23:34 Very nice Exxos, no issues with having a separate rom card. Under this configuration though will it be possible to have the decoding needed for 2.06?

The 206 decoding is done in 2 of the 3 GAL's on the booster board. It will need 1 wire to go to the new ROM board (will design a new one) to bypass the GLUE's ROM chip enable. Easy enough.

Thats what I figured but I'm ok with a wire to bring the decode over. :thanksyellow: :thanksyellow: :thanksyellow:

Looking good. Is it still running at 16mhz or faster? Still need the buffer board on the mega etc?

Forgottenmyname wrote: 24 Oct 2018 18:53 Looking good. Is it still running at 16mhz or faster? Still need the buffer board on the mega etc?

Its the V2.2 booster design, nothing else.

Moving things about a bit... Still have a break :roll:

I will try doing a bit of routing on the VCC layer , I also really should add in the resistor SIL's as well.

A bit of tweaking later.. Resistor packs also added...

It is now actually routed on 4 layers! The bottom layer still dedicated for GND. Also minimal routing number 5V layer..

I also taking the STFM ROM board, with the use of a SMT ROM socket, hopefully this will physically fit how it is basically looking now.. I will try and check later..

Basically this board would hold TOS104 & TOS206 for use with the new booster design.. I also thought I could add the UBE Switch on to this as well..

NOTE - before anyone gets excited, TOS206 will not function on this ROM board without the booster.

Exxos, looks like it will fit in a mega however the rom card is for a 1040. I suspect I can hack the mega fast rom card to take the decode signal from the accelerator. I'm going to install the clock cleanup and run with it it to make sure no issues arise. looks good!

PaulJ wrote: 25 Oct 2018 14:06 Exxos, looks like it will fit in a mega however the rom card is for a 1040. I suspect I can hack the mega fast rom card to take the decode signal from the accelerator. I'm going to install the clock cleanup and run with it it to make sure no issues arise. looks good!

The MEGA ROM card can be used, just re-route the CE line to the booster instead. Simple enough.

The only reason I am really redoing the STFM one, is I only have 4 in stock, and I want to make the board smaller and cheaper if possible. So while I am at it, I will gear it up for the booster as well.

The only slightly annoying thing about all this, as I will have to stock all the ROM's with TOS104/206 as well :roll: