Hi, I have a US M100 but Stephen wanted to be sure I had a US model before he sold me the REXCPM, and he said it wouldn't work in a European model. He didn't mention selling me a 'European' version so I assume one didn't exist back then.
I think there are some hardware differences as well, and he sent me some pictures. Jonathan >----Original Message---- >From : b.kenyo...@gmail.com >Date : 2022-02-04 - 03:06 (CEST) >To : m...@bitchin100.com >Subject : Re: [M100] Tandy Model 100/102 modem pickup line > >Wow, ok, I hadn't considered that someone had replaced the main rom. >All bets are off in that case. > >I would not be surprised if the modem doesn't work at all with the wrong >rom installed. The main rom has to match the hardware and the North >American main rom does not match the European hardware, and the modem is >definitely one of the things, like the keyboard, which is different >between countries. > >You only do something hacky like that fully accepting that you are >breaking some things in order to get some other things. But you didn't >make that choice, you're stuck with something someone else did and then >sold to you. > >I would definitely start with putting the unit back to stock condition, >meaning put an EU main rom back in and remove the rex#, just as a first >diagnostic step just to establish a baseline even if you want to go back >to the hacked-up condition later. > >Did the seller at least supply the original rom with the unit? If not, >it might be taped inside. > >I don't know of any copies of the EU rom for download. Asking here or on >two facebook groups is probably your best chance to find one. >https://www.facebook.com/groups/Model.T.Computers > >This one in particular has a lot fewer, but mostly European members: >https://www.facebook.com/groups/olivettim10 > >I think it can be dumped out the serial port with a BASIC program, so >anyone should be able to dump it for you without having to desolder the >chip or use an eprom burner. I'll try to find the basic program for >dumping the rom out the serial port, that way you can make it as easy as >possible for someone to do the favor by having some directions ready to go. > >If the REX# really is incompatible with the EU main rom, and Steve can't >produce an EU version of the REX# firmware, then you'll probably just >have to choose one or the other for that unit, either have the hardware >all work properly, or have REX# on that unit. > >-- >bkw > >On 2/3/22 17:40, Cedric Amand wrote: >> Thanks, i'll try all that. >> I must admit I don't fully understand what the REX# does, as I've only >> use it to make backups of the RAM, but it's features go way beyond that, >> so it's unclear to me if - for example - the tsdos that comes with would >> be "US minded". >> >> From what I understand, the original owner (which may even be in this >> list) had to replace the belgian/european ROM with another ROM, most >> likely a US one, to be able to use the REX# ( that's what I got from >> what he told me, don't quote me on this ) >> >> All these changes could, maybe, break my modem. >> >> However i've been looking at the schematics of the modem part and all of >> this is as simple as can be, it's really purely analog in many areas, >> and there is no way on earth any of this is software controller. I mean >> : the thing doesn't care if the dial tone is 440, 600 Hz or anything (at >> least looking at the hardware I see no way this would be measured, even >> less handled by software) >> >> So if I take for granted my M102 is a Belgian.european one (it' has the >> sticker of the telco!), I guess the electronics where adapted to our >> particular voltages. >> What could be a possibility if that some of these are now out of spec >> >> One final comment ; if I hit F4 (TERM) in TELCOM, the M102 starts to >> emit an awful noise (like if it was connected to a data line !) it does >> that even when the M102 is not connected to anything ( I mean, no wire >> connected to it at all) It is also, afaics, completely crashed (i have >> to reset/reboot) >> Is that "normal" ? >> That would point to a problem with ROM/REX... >> >> >> thanks again for taking the time to help weirdo that wants his analog >> modem to work :) >> >> >> >> Le jeu. 3 févr. 2022 à 23:32, Brian K. White <b.kenyo...@gmail.com >> <mailto:b.kenyo...@gmail.com>> a écrit : >> >> I can tell you one thing for sure, the REX has no effect on the modem. >> >> But you can prove that to yourself by just removing it. It doesn't hurt >> anything and it won't even lose it's programming. Just pop it out, and >> see that it made no difference. >> >> Have you tested the line with a plain analog telephone? >> >> Have you verified the modem cable doesn't have a broken wire? >> >> Since you are talking about dialing vs answering, is the the ANS-ORIG >> switch in the ORIG position? (Answer vs Originate) >> >> Measure the voltage between tip & ring when the the modem is >> on-hook. It >> should be 48vdc >> >> Measure the current on either tip or ring when the modem is >> off-hook. It >> should be about 20ma, at around 9vdc (actually a wide range from 3 >> to 12) >> > > >-- >bkw >
