coonsgm wrote: Tue Sep 10, 2024 2:05 pm
I'm not too concerned...not a whole lot of reason to ever use two ROM TOS. Working with 6 ROM's is what's needed.
Well actual EPROMs that work with a 2 ROM setup seem to be thin on the ground unless you build some sort of adapter, so for me and my large stock of 27C256's, 6 chip is always the way forwards.
Working is working.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Thanks for this great tutorial Jonnie.
Just wanted to add, much like coonsgm my Mega 1 would not boot until i removed the 74LS11 chip.
As soon as i desoldered it, booted straight away no problems.
I also found a service bulletin that Atari put out and they do say that it needs to be removed.
Strange that it that it worked for you left on the motherboard!
6 rom mega upgrade.jpg (288.04 KiB) Viewed 1870 times
