exxos's Atari, Amiga & retro forum

REQUIREMENTS

STE DUALTOS PCB and FAST ROM.


STEP 1

Solder the thin wire as shown in the image below.

NOTE - This needs to be a 74F257. Some STE's may have a 74S257 chip for U405. This chip does not output correct TTL voltages to drive the booster. As such the machine will likely be unstable or not boot.


STEP 2

Route the wire similar to below.



STEP 3

The 5 SIL resistors should be removed. I have sockets in my motherboard as shown below, but resistors should simply be removed when fitting the booster as they are on the booster board. The booster *might* work with the original SIL's but I don't recommend leaving them in other than initial testing.

If the booster board has the "472" number stamped on the resistor packs then there is no need to remove the motherboard SILs assuming they are the original values (generally 10K or 4.7K depending on motherboard revision)

Please also check P100 on the motherboard is a 1.2K value (122J on the resistor pack). If it is not that value then it must be replaced.


STEP 4

Insert the "Dummy CPU". This may be a tight fit, but do not force it.


STEP 5

Trim the wire as required and solder to the bottom of the board as shown below.


STEP 6

Using a torch, carefully align and push down the booster into the socket.


STEP 7

Solder the white wire as shown below.


Check your work and you should be able to power on without any issues. Use GB6 to verify operation.

When closing the case with metal shielding, use the spacer as shown below. This will keep pressure on the board.

KNOWN ISSUES

Machine will not boot without pressing the reset button.

Solder a 22uF capacitor across C100 or replace it with a higher value.


Machine is unstable.

Mostly down to bad connections, or Parity simms which will result in problems like the video below.





2024 UPDATE - 1712 SHIFTER RELATED ISSUE
Various issues (even on stock machine) with the 1712 shifter.
https://exxosforum.co.uk/atari/last/1712fix/index.htm

FAQ

Q) Do I have to use the "Dummy CPU" part ?
Yes. Without it the pressure of the socket contacts will start to bend the pins. When this happens booster will pop out of the socket and be virtually impossible get to stay in otherwise.

Q) How do I enable 8MHz mode
Connect the SW pad on the booster some 0v somewhere to disable the boosters 32Mhz mode and enables 8MHz mode.

Q) Can I use different wire ?
Short answer,No. You should use the thin wire which is supplied in the kit. Using different wire can cause stability issues or worsen video interference.

Q) Can I use different simms other than the exxos brand ones?
Yes. The only known requirement for memory is that they are not parity simms.

Q) Ultra satan is unstable after fitting the booster.
You need to do the DMA fixes. See topic 3. https://www.exxosforum.co.uk/forum/viewt ... =17&t=1585 Also not removing the motherboard SIL's can cause new DMA issues.

2024 STE V1 SERIES DMA ISSUE ALPHA FIX:

(see bottom of the page)

https://exxosforum.co.uk/atari/last/V1STE/index.htm

This fix is to only be applied if you have DMA related issues *only* when the booster is used, be it in 8MHz or 32MHz mode.


STORE LINK
https://www.exxosforum.co.uk/atari/store2/#0290