Fitting the STE V1 32 MHz booster with socket
Posted: Mon Aug 28, 2017 8:10 pm
Hi,
just want to share my experiences. Have no problems with soldering in the complete stuff, wasn´t complicated IMHO. And some good manuals online, too. But one thing I don´t like: I´m not a fan of directly soldering in PCBs such PCBs...
So I try to use a "socket". I take all the parts in the D.I.Y. kit and mount the male header with the thicker and shorter pins towards the STE mainboard. Then I take some precision female single row header, cut them in the needed stripes and it fits... absolutely perfect! The upper shielding sits absolutely without any pressure over the whole booster PCB. Take a look here:
2nd goal... you can also plug one of the "funky" PLCC sockets into these headers to test the old 8 MHz CPU quickly, if anything went wrong.
Another thing to share... after installing the STE booster the system starts, but a lot of graphic disturbation oocurs, mostly during I/O processes. I take a look at the 32 MHz signal on Pin 1 of the 22V10 GAL and it was... horrible. Approx low voltage 1,76V, approx high voltage 2,21V... this is more analogue than TTL
So I replace the 74S257 with an 74AHCT257 and all fine. Now typical Low is 1,1V and high peak is 3.4V... this is much more as it should be.
Best regards, Jurgen
just want to share my experiences. Have no problems with soldering in the complete stuff, wasn´t complicated IMHO. And some good manuals online, too. But one thing I don´t like: I´m not a fan of directly soldering in PCBs such PCBs...
So I try to use a "socket". I take all the parts in the D.I.Y. kit and mount the male header with the thicker and shorter pins towards the STE mainboard. Then I take some precision female single row header, cut them in the needed stripes and it fits... absolutely perfect! The upper shielding sits absolutely without any pressure over the whole booster PCB. Take a look here:
2nd goal... you can also plug one of the "funky" PLCC sockets into these headers to test the old 8 MHz CPU quickly, if anything went wrong.
Another thing to share... after installing the STE booster the system starts, but a lot of graphic disturbation oocurs, mostly during I/O processes. I take a look at the 32 MHz signal on Pin 1 of the 22V10 GAL and it was... horrible. Approx low voltage 1,76V, approx high voltage 2,21V... this is more analogue than TTL
So I replace the 74S257 with an 74AHCT257 and all fine. Now typical Low is 1,1V and high peak is 3.4V... this is much more as it should be.
Best regards, Jurgen