Sorry; how is this any better than the M100ROM on Bitchin100? You have to remove each M100s main board and unsolder the ROM socket? Aside from any considerations of 'keeping it original' that's not everyone's cup of tea, but if you really want to do that then of course you can do it with the M100ROM as well.
On the other hand, the M100ROM is normally a plug-in solution not requiring any mods to the M100 at all; if you really need to reprogram the chip, an adapter is pretty simple, would probably not take much longer to make than unsoldering the M100's socket, and would work for as many (unmodified) M100s as you like. You want to use an EEPROM? DIP 27C256s are dirt cheap and thick on the ground but I don't see why a compatible DIP EEPROM would be a problem. And of course the M100ROM gives you the option of adding TS-DOS or any option ROM of your choice while you're at it for essentially the same cost and assembly time. But to each his/her own I guess; maybe I'm a little biased but personally I'd rather spend 15 minutes or so making a one-time programming adapter (if I in fact ever need one) than removing the main boards in all my M100s and unsoldering and replacing the main ROM sockets... m ----- Original Message ----- From: Brian White To: Model 100 Discussion Sent: Wednesday, June 01, 2016 10:45 PM Subject: Re: [M100] Main rom using 28C256 plcc How many times do I have to write plcc in one mail? :) Physically it's all identical to the previous 27C256 plcc version. I am currently using the 27C256 version in 2 M100's already, so the physical fit is tested. Just to be clear, it requires desoldering the original dip socket and putting this adapter in it's place. And the adapter has a plcc socket on it. So in the end you have a socketed standard 28C256 instead of a socketed non-standard LH535618. And you can re-program the eprom without any special adapters or a test-clip, because the eprom itself comes out by itself. It's only for the early model 100's of course. Later ones you just use a 27C256 DIP with no adapter. -- bkw On Jun 1, 2016 10:10 PM, "Stephen Adolph" <[email protected]> wrote: Nice find. Ebay source or retail? Let us know if there is just enough space. Is the 28c256 a dil package? Or soic? On Wednesday, June 1, 2016, Brian White <[email protected]> wrote: > https://oshpark.com/shared_projects/bCqiBZLI > > This same guy had a 27C256 version, but erasable 27C256 lcc are really hard to find. You can buy OTP parts new, but not erasable. > > So he made a 28C256 version. You can still buy new 28C256 plcc. > > Maintaining a socket of some form is more important than I realised at first because I wasn't aware that eproms and eeproms might lose bits in as little as 10 years. So an eprom/eeprom absolutely will need to be re-flashed again sometime. > > I found these low profile round pin headers to use with it. You need both qualities, round pins and close spacing between the motherboard and the module. > http://www.king-cart.com/phoenixent/product_name=HWS5231 > > Untested yet. I'm ordering now. > > -- > bkw
