I see that my Model 100 is one of the ones so afflicted. Is there any reason to not do the repair?
On Fri, 13 Jan 2023 at 14:14, Stephen Adolph <[email protected]> wrote: > >> Hmm. 3 of my 10 M100 have this defect. > Good to know!! > >> >> On Friday, January 13, 2023, <[email protected]> wrote: > > >> Some of the original M100s have the wrong resistors in part of the RS232 >> handshake circuit. The voltage drop is so high that with the signal looped >> back it is just barely sufficient. The Backpack eavesdrops to know when to >> power itself back up and this minuscule additional load is too much. The >> symptom is that the Backpack responds once and then stops. > > >> I have tried to attach a tech bulletin that Tandy put out back in the day >> that describes the fix but it was too large. I zipped it up with the M200 >> andM600 tech bulletins here: >> https://1drv.ms/u/s!AtH4vpaZnzX7lq9GsKp0I4qvY59yCw?e=yAcrwQ The >> alternative is to set both lookback switches away from the dot. The >> Backpack does not eavesdrop in this configuration so it can't wake itself >> up. You can adjust the timeout to compensate. > > >> This is only the third M100 I've com across with this issue. I have one >> of them too 😊 At some point in the future I'll do a video on the fix per >> the Tandy tech bulletin. > > >> Jeff Birt > > >> -----Original Message----- > > From: M100 <[email protected]> On Behalf Of Philippe Van >> Lieu > > Sent: Friday, January 13, 2023 2:02 PM > > To: [email protected] > > Subject: [M100] Backpack-Plus with REXCPM help > > >> Hello everyone! I recently bought the Backpack-Plus for the M100, and I >> LOVE the thing. I want to thank you Jeff Birt/soigeneris for making this >> wonderful device to help keep these classic machines alive! > > >> That said, I'm having an issue getting it to work properly on my >> REXCPM-powered M100. Fortunately the Backpack works fine on my normal > > M100 so I figure the Backpack isn't the issue, but every time I try to run >> it on TS-DOS on my REXCPM'd M100, I get a "device not ready" error albeit >> after working only once beforehand. > > >> I read the instructions and tried to adjust the timeout/sleep settings to >> something like 5 minutes via the CLI, but that didn't affect it. I also >> read the "Use with CP/M-100 and REXCPM", but that's just the initial >> installation instructions. I also saw the suggestion of using TS-DOS v4 or >> higher, but that also didn't have a positive effect. > > Finally, a saw the paragraph on page 45 about making sure that the LOOP >> switch is set to LOOP in order to ensure TS-DOS keeps the Backpack-Plus >> awake, but neither that nor power cycling the Backpack-Plus woke it up. > > >> So I'm at a loss on what I can do to get it working. I went through the > > M100 mailing list archive, and it sounds like other REXCPM users haven't >> had any issues using the Backpack... so I suspect that maybe I'm doing >> something wrong. I'm open to any suggestions, and I thank you ahead of time >> for your help! > > >> --- Philippe > > >> >> >> >> >>
