Dear all, thank you for your assistance. It was the OPTION ROM socket. 👍 👍 After bending all pins a bit to the center and putting a REX classic back into its place it works. Puuh, no further actions necessary. I was not aware of the weakness of the pins, so for the future I´ll be more careful with that. Thanks again for your help Regards Georg
Georg Käter Gangolfsweg 44 D-52076 Aachen Tel. : +49 2408 7194987 Fax. : +49 2408 7196758 Mobil : +49 171 4839954 E-Mail : [email protected] ========== Ihre Nachricht ========================================== von : Brian White <[email protected]> gesendet : Mittwoch, 30. November 2022, 04:03 an : Club100 Listserv <[email protected]> Betreff : [M100] Model 102 - Help needed: OPTION ROM stopped working __________ Originalnachricht _______________________________________ > Sounds like likely a simple mechanical problem of bent pins not making good > contact. > Do all the pins in the socket make good contact with the rom? > You obviously didn't do anything too bad like kill the 5v supply in the > 102 or kill the chip if both the 102 still runs and the chip still works > in other machines. > One thing you can do just to verify the mechanical contact between the > socket and the rom is, just insert the rom and continuity test each pin > from the socet to the rom adapter. There is enough socket pin > still exposed to touch a meter probe to the socket pin whike the rom is > plugged in, and you should be able to get > the other meter probe to touch the pad on the rom adapter without touching > the > socket pin if you're careful, or touch the pin on the chip but remember > to account for the pin re-mapping for some pins. Basically individually test > the continuity from the socket to the chip adapter for each pin. > Another thing you can do to test the electronics feeding most pins > inside the 102 without taking everything apart, is check with a > continuity tester setting on a multimeter, between equivalent pins on > the option rom socket and the system bus connector on the back. Only a couple > pins like /CS and /OE are going to be isolated just to the socket. vcc, > gnd, address and data lines are all shared. > Get the pinouts for both ports from the service manual > https://archive.org/details/tandy102servicemanual/page/n27/mode/2up > Wow, Never noticed the 102 service manual barely even mentions the > option rom socket. No pinout or interface description like all the other > ports. But you can get the pinout from the schematic, top center page > 68, and the system bus over to the right same page. So you can see AD0 > is pin 11 on the optrom and pin 5 on the bus connector. > The ALE, /CS, and /OE pins won't have any copy but the rest will. To test > those few pins you'll need more than a meter, you'll need a scope to tell if > they pulse while you try to access the opt rom. But at least a cheap toy > scope is good enough for these speeds. But that's getting fancy and you can > do the simpler stuff first. __________ Ende Originalnachricht __________________________________ Vertraulichkeitsinformation: Diese Nachricht ist vertraulich. Die Informationen dieser Nachricht sind ausschließlich für die persönliche und vertrauliche Verwendung durch den/die oben genannten Empfänger bestimmt. Wenn Sie kein beabsichtigter Empfänger sind, bitte lesen, kopieren und verwenden Sie die Nachricht nicht. Machen Sie sie nicht anderen zugänglich. Bitte informieren Sie uns umgehend über den Zustellfehler und senden Sie die Originalnachricht per E-Mail an uns zurück. Confidentiality Notice: This message is confidential. The information contained in this message is intended only for the personal and confidential use of the recipient(s) named above. If you are not the intended recipient, please do not read, copy, or use it and do not disclose it to others. Please inform us immediately of the delivery error and return the original message to us via e-mail.
