Hi Jeff, Thank you - I noted my serial # was after the 306000001 mark, and verified the 330 ohm resistors are in fact on my board. I then took a closer look over the board and noticed just about every electrolytic cap leaked. The flipflop near the power supply area was also warm, so I powered it off and may order some caps. I’m thinking at this point a recap before digging into the RS-232 port any further would be a good place to start.
This is a fantastic group, thank you all for the replies! > On Jul 9, 2023, at 7:12 PM, <bir...@soigeneris.com> <bir...@soigeneris.com> > wrote: > > The TPDD1, TPDD2, Backpack, etc. use 19200 successfully. If you can adjust > the intercharacter delay on the TNC is might help. Also note that some early > M100s had the wrong resistors in the output lines for the RS232 port. They > fitted 5.6K from factory but they quickly revised that down to 330ohm as some > devise would not work with it. > > I did a video on the factory mod a while back. A link to the technical > bulletin is in the video description: > > https://youtu.be/KPFnwv_nDD8 > > Jeff Birt > > From: M100 <m100-boun...@lists.bitchin100.com > <mailto:m100-boun...@lists.bitchin100.com>> On Behalf Of Gregory McGill > Sent: Sunday, July 9, 2023 5:40 PM > To: m...@bitchin100.com <mailto:m...@bitchin100.com> > Subject: Re: [M100] Intermittent problem at higher baud rates on RS-232 > interface > > there's no hardware flow control on the 100 with telcom > use a better terminal and hardware flow control at any baud rate over 2400 > > > On Sun, Jul 9, 2023 at 3:19 PM Jesse Bertier <berti...@gmail.com > <mailto:berti...@gmail.com>> wrote: >> First time getting my hands on a model T. I am attempting to connect to a >> TNC at 9600 baud. I have both matched for 8,N,1 and 9600 baud. TNC works >> with other PCs. I’m using TELCOM and set the parameters correctly. What >> happens at 9600 baud is the text coming into the m100 is garbled mostly and >> on occasion some valid words come across. When I set both to 300 baud, >> works perfectly. It seems to be problematic if there’s a solid block of >> text coming in, like a string of 20-30 words for example. >> >> Before I dig into the problem with the service manual and get out the scope, >> does anyone know if these are supposed to work well at 9600 or up to 19,200 >> ? Or, does the buffer or machine get overloaded at higher rates? Is TELCOM >> the issue? >> >> Sent from my iPhone
