Hello to all, I own two M102 PPPCG2007A*01 and PLX144FH1X version also. Checked on both connection to RS232 connector and it´s the same. Means PIN20 is connected to PIN4 on M33. Regards Georg ========== Ihre Nachricht ==========================================
von : Bert Put <[email protected]> gesendet : Mittwoch, 19. März 2025, 13:46 an : [email protected] Betreff : [M100] Tandy 102 - Euro PCB layout / schematic & RS232 problem __________ Originalnachricht _______________________________________ > Hello, > I don't have an official schematic but I do have a M-100 that was purchased > in Australia. That M-100 was missing its modem part because Australia uses > CCITT tone pair where USA uses Bell, so the modem was not authorized for use > in Australia. > The IC numbers you quoted for the M-102 (I have one of those as well) are > very close to the modem and UART chips, so I would not be surprised if your > unit has been hobbled in the same way as mine. > I hope that helps! > Regards, Bert > On 3/18/25 18:21, Stephen Adolph wrote: >> I think there is a very good chance the part is the same and it is wired > >> up the same. Hopefully you can confirm pin 2 of M33 connects to R139 > for >> example. Also that pin 11 on M24 connects to pin 3 on the rs232 > port via >> a 6.2k resistor. >>> You get the idea here I'm sure! >> Good luck >> Steve >>> On Tuesday, March 18, 2025, James Reed <[email protected] > >>> <mailto:[email protected]>> wrote: >>> Hi all >>> I've just bought a Tandy 102 and am having a few issues. I'm in the >> UK, and it looks like the one I bought was used in Germany. As a >> result it has the European PCB number PPPCG2007A*01 referenced here: >>> https://bitchin100.com/wiki/index.php?title=Model_and_ROM_information >>> <https://bitchin100.com/wiki/index.php?title=Model_and_ROM_information> >>> Whilst there is no obvious battery leakage, it does have signs of >> corrosion here and there. I have had to replace most of the F key >> switches with new ones as the old ones had very rusty legs, and also >> a few of the keys needed cleaning. >>> The big problem I now have is that the RS232 port transmits data >> fine, but does not receive anything. I noticed that there was some >> quite significant corrosion on pin 20 of the UART (which is where >> the received data is fed), and I've cleaned it up and reflowed the >> solder joint but it still doesn't work. I'm wondering if the trace >> leading from pin 20 was damaged although it's hard to see where it goes. >>> The Tandy 102 service manuals all seem to reference the US edition, >> and the PCB layout does not match mine. The schematic is also for >> the US edition, and shows pin 20 of the UART connecting to pin 4 of >> another chip, M33. There is no continuity between pin 20 and pin 4 >> of M33 on mine, but I'm a bit nervous as to whether the schematic is >> actually correct for the Euro edition I have. >>> So - does anyone know if there is a schematic / PCB layout available >> for the edition I have? >>> If not, does anyone have a Euro edition and would be willing to >> check if pin 20 of the UART does indeed go to pin 4 of M33... or >> somewhere else? >>> It's really frustrating, this unit is in great condition and it's >> almost working... but without this I can't use any TPDD emulators >> etc and it's essentially an ornament. >>> Any help would be most welcome >>> James __________ Ende Originalnachricht __________________________________
