This is a post of a message from the Usenet newsgroup, comp.sys.atari.st about installing TOS 2.06 in a 1040ST without the TEC board. It seemed to work for the author of this post, but there are no guarantees when 'hacking' your computer... - - - - - - - - - - - - - - - post follows - - - - - - - - - - - - - - - - - - Well, thanks to everyone who replied to me about where to shove and where to get TOS 2.06 I have gotten it to work in my 1040ST without a TEC. The solution requires 10 wires from the GLUE chip, 3 TTL devices (<$1) and 5 pins of each ROM lifted. The circuit I used is shown below: TOS 2.06 Address Decoder and DTACK Generator: (19,XX) ROM2_>--------------------------+ +--------+-----+--------+ | | Chip | +5V | Ground | 74F138 | +--------+-----+--------+ +--------------+ | | 74F138 | 16 | 8 | (11,52) A23>---|a0(1) q0(15)|o- | | 74F08 | 14 | 7 | (10,51) A22>---|a1(2) q1(14)|o- | | 74F06 | 14 | 7 | (09,50) A21>---|a2(3) q2(13)|o- | 74F08 +--------+-----+--------+ | q3(12)|o- | _______ (12,06) AS_>--o|e1(4) q4(11)|o- | \ \ (08,48) A20>--o|e2(5) q5(10)|o- +--o\a(1) \ (55,09) R/W_>---|e3(6) q6(9)|o- ) y(3))o--------> CE_ | q7(7)|o---*-----o/b(2) / +--------------+ | /______/ | +5V | _|_ | 330 Ohm | | | | | | |_| | 4 /| 3 | 2 /|1 | 74F06 (Must be open collector) (50,10) DTACK_<-------o< |---*---< |o-+ \| \| +5V 74F08 | ____ +--|4 \ | 6 )-------------------------->BA17 (05,45) A17>------------|5__/ +5V 74F08 | ____ +--|9 \ | 8 )-------------------------->BA16 (04,44) A16>------------|10_/ Note: Numbers in parenthesis on the left are (GLUE pin,68000 pin). Parts needed are: 1 74F138 1 74F08 1 74F06 Different families (LS, ALS, AS) may be substituted for the above parts. The buffer that drives DTACK_ must be open collector or if a 7406 part can't be found a tri-state buffer can be used as long as it is used like the example below: 74LS244 +-------------+ | oe(1)|o-------- to pin 7 of 74F138 DTACK_<----------|y0(18) i0(2)|---+ | | | +-------------+ | | GROUND I have been working on a document that explains in detail how I installed TOS 2.06 (the mechanics is the main deal). When I finish it, I would like to place it in the archive but I don't know how. Could some one please tell me how to submit a text file. Also, if anyone would like a copy of the current document just send me email and I'll send you what I have. Bye Ted Rossin