Digging up an old thread: Hi! (Also hoping this doesn't come through twice; if it does, apologies for the 2nd copy.)
Sorry for not responding for a while, seems I misconfigured procmail and all the m100 list messages got redirected to some obscure mailfolder... so hency my reply half a year later. Ah well, this turned out to be a long-term project after all. After some feedback from the list last time I posted, I got kinda demotivated - seems the audience here isn't that interested in the keychain-size M100 I had in mind... perhaps I could scale things up, add ports, ...? and I kinda lost sight of what I wanted to do. Meanwhile, some other things also happened in life, caused me to drop the project. When I got my time back, other interesting stuff got a higher priority, and before you know, a year passes. I recently found the PCB of this project back in a drawer. I have a nice 3d-printer on order, so one of the things I worried about (the mechanics of a tiny DIY physical keyboard) will be something I can iterate on way faster that way. I also started working on an emulator for the Model 100 - I know about VirtualT and others, but I haven't found an emulator that was easy to strip down to run on a microcontroller, and I don't mind building something from scratch; as coding goes, emulators are pretty fun to do. At the moment, it still runs on a PC and it already boots the ROM - I can't check anything else as I haven't hooked up a keyboard yet. I also decided I would keep on doing what I originally had in mind - a tiny keychain-sized but otherwise fully functional Model 100. I am sure you guys would like to see all sorts of bells and whistles and other sizes, but to be real - I'm doing this as a hobby next to a full-time job and I'm not going to be in any state to mass-produce this thing any time soon. By creating what I want and then releasing the schematics, sources and drawings under an open-source license, hopefully others can customize that and build whatever they want. Plan is perhaps to change chips - the old design had an STM32, for ultra-low power so the M100 would work forever on a rechargable coin cell, but I work for Espressif and we make some really nice WiFi chips that are powerful enough to easily emulate a M100. With some hackery I may be able to combine WiFi with the M100 OS in such a way that documents on the tiny M100 will automatically get synced with a server. That way, it would actually be usable - you have a small keyboard to type out whatever thoughts you have, or work on a small BASIC program on the go, and when you come home, the files will already be accessible on your laptop. It could also work as a modem, allowing you to Telnet into all the BBSses, MOOs etc that are out there. This solution will be a tad more power-intensive, but with a bit of luck I'll still get more run-time out of a tiny LiIon than the original M100. Cheers, Jeroen On 8/22/19 5:34 AM, Comet wrote: > Hello Jeroen, > > We haven't heard from you lately.?? The model 100 bus and option ROM > port are useful, as are the bar code reader port, etc. > I highly recommend that you ensure that your sound emulation is good > -- music/sound processing is one of the "killer apps" for me.?? :-) > > On 6/2/2018 4:04 AM, Jeroen Domburg wrote: >> Hi all, >> >> TL;DR: I'm building a tiny M102. >> >> Let me first re-introduce myself on this list. Hi, I'm Jeroen, also >> known as Sprite_tm on the wider Internets. I was on this list around >> 2001, which is way longer ago than I thought it was. At that time, I >> wanted to see if I could convert the Olivetti M10 I bought at a flea >> market to accept M100 roms. I actually succeeded: took but a small >> conversion routine for the different keyboard layout to make the M100 >> ROM work in the M10. Talked to Rick Hanson at that time to ask if he >> could send me some ROM images. I'm sad to read he has passed a while >> ago... always seemed like such a pleasant guy in the email >> conversations. >> >> Anyway, why am I back? I nowadays live in Shanghai, doing electronics >> stuff, and recently I directed my hobby into re-making the machines I >> enjoyed back in the days This already has resulted in a matchbox-sized >> Game Boy >> (https://hackaday.com/2016/11/28/tiniest-game-boy-hides-in-your-pocket/), >> >> and a tiny Macintosh Plus (http://spritesmods.com/?art=minimacplus). >> >> Now, I decided to see if I could do something similar to this: make a >> tiny version of the TRS80 Model 100 or 102 (haven't decided yet). The >> plan is to use a newfangled low-power STM32 ARM processor for this; the >> processors that are around nowadays are actually pretty quick (80MHz), >> have a fair amount of RAM (64K, twice what the M100 had at maximum >> capacity!) and are even more efficient than the 80c85 (a few micro-amps >> per megahertz). Also, they have a bunch of peripherals integrated, so I >> can get away with not much more than that chip. >> >> Here in China, it's actually pretty easy to get the basic parts for >> this. The most important part, obviously, are the LCD and the keys, so I >> decided to start there. I found a nice and tiny (and cheap!) 256x64 >> display, which could be a nice stand-in for the 240x64 LCD in the >> original hardware. To test it out, I connected it to my laptop and did a >> hack to get VirtualT outputting data to it: >> http://j0h.nl/AqkB >> (And yes, it's a bad picture... I shouldn't take pics in bad lighting >> around midnight, I guess. For reference, the purple thing underneath is >> a credit-card sized metro transportation card.) >> >> For the keyboard, I decided to go with the bare metal domes you >> sometimes see in somewhat cheap-ish but still ok feeling keyboards for >> remote controls, old-school brick phones etc. The nice thing is that >> these domes are about US$0.005 each. The bad thing is that they need a >> specific PCB layout to work... so I had to make a PCB for this. Luckily, >> this is also cheap-ish here, although the gold-plating set me back a few >> quid more than I'd liked, and I'll probably re-spin these because they >> have a few mistakes in them. The keyboard part seems to work, however. >> Here it is while building it up: >> http://j0h.nl/AaoB >> >> And here is where I am now. I've used kapton to hold down the rubber >> domes, and I can actually already type on this; the domes are all well >> worth the half a cent each I paid for them, nice and clicky. I also >> installed the microprocessor and USB-port, and at this stage I can blink >> the power LED, so at least the hardware seems mostly okay. >> http://j0h.nl/AKsB >> http://j0h.nl/B6wB >> >> >> So, why am I posting this? I dunno, I like writing about this I guess, >> and maybe you guys have some good ideas for continuing. I'm pretty sure >> I can write the emulator without too much effort. The USB port is >> probably going to be used for a serial port; I may also use it to upload >> things like option ROMs. (The microcontroller has 256K of flash, so I >> should be able to fit a few.) I also need to think about a case: I have >> a pretty kick-ass Formlabs 3d-printer at work, but my workshop does not >> have many mechanical tools. In the end, I'll also add a LiIon battery: a >> tiny 150mAh one probably is long enough to let the entire thing actively >> work for 80 hours or so. >> >> Hope a project like this is appreciated on this list; if not, I'll >> happily keep working on this in silence. My experience with the M100 is >> nil, however, so if you people see things I missed to make it an even >> better M102 replica, I'd love to hear this. >> >> Cheers, >> Jeroen >> >> >> >> >> >> >> >
