https://gist.github.com/bkw777/52d85d89eeff8445cc667685d05ea94d
includes some links to sources as well as specs 26 awg or 0.4mm bkw On Tue, Nov 28, 2023, 8:59 PM Mike Stein <[email protected]> wrote: > I probably missed it and can't easily find the previous discussion, > but what diameter wire do you suggest? I see the hole size 0.6mm/24 > mil but not the wire gauge. > > Thanks! > > On Tue, Nov 28, 2023 at 7:56 PM Brian K. White <[email protected]> > wrote: > > > > You have lost me. > > > > If you want to dump or re-write the flexrom, you can just do it it it's > > programming adapter. > > > > I thought you wanted to dump the original rom? > > > > And if you want to avoid all the hardware actions while changing the > > main rom, that's exactly what REX Classic allows. It's purely software > > once you set that up, and even if you botch both primary and secondary > > images, you only need to open the option rom compartment instead of the > > whole machine to revert to the internal eeprom. > > > > If you have a soic-28 test clip, you *might* be able to program the > > eeprom without removing from the machine. Mostly it should be ok, the > > board allows the programmer to drive /WE for instance, it's definitely > > ok to program the chip directly with a test clip if the board is not > > installed in the machine. But but one thing I don't know is, if the > > board is installed in the machine, all the pins are connected to the > > bus. Mostly that should be ok but one thing I don't know is what happens > > when the programmer tries to provide power on the vcc pin? Does it power > > up the whole machine? Even with the memory power switch turned off, > > which normally kills everything, this would be injecting power to the > > rail from a point "inside the walls". > > > > If you're worried about the legs, and you're right that it would be a > > pain to repair a loose one after the frame was cut away, I now actually > > prefer gold plated plain brass wire. > > https://gist.github.com/bkw777/52d85d89eeff8445cc667685d05ea94d > > > > The advantages are, > > - just wire, no special shapes to cut off or anything, no single special > > supplier > > - a few feet makes hundreds of 6mm legs > > - the wire is round, so there is no problem with it rotating when > > loosened and resoldered > > - gold plated > > - repair/replacement of a broken leg is trivial > > > > The disadvantages are, > > - each leg has to be soldered individually, no one-piece connector or > > frame like with a normal pin header > > - no simple supplier to point to, it's such a generic thing that there > > is no part number or such, except in large quantities from bulk > > suppliers. The various suppliers (for small quantities) I've found have > > all been transient like Etsy or Ebay links that don't work a year later. > > And it's easy to end up with gold colored aluminum wire or brass wire > > that isn't gold plated (which starts tarnishing within a year), since no > > one selling the stuff is writing their descriptions for electronics use. > > I have also gotten wire from aliexpress that was thinner than claimed, > > which ends up being too thin and weak despite you buying the correct awg > > or mm number. > > > > But if you do get some, then you have a lifetime supply after that. > > > > The preloaded bom carts with the pcbs have the sil leadframes just > > because it's an actual part that can be ordered normally along with > > everything else, and is both a little cheaper and a little more > > convenient to solder than the MillMax or Keystone micro pins which could > > also be ordered as part of the bom. > > > > -- > > bkw > > > > On 11/28/23 13:32, runrin wrote: > > > This is a good idea, but I've already got my new EEPROM in there and > > > every time I remove it and put it back in, I get worried I'll break off > > > one of the legs and have to resolder it. > > > > > > The leadframes used to make DIP pins on Brian's FlexROM adapter board > > > work well, but I really don't want to have to replace them when I > > > inevitably break one off. > > > > > > Would you use a BASIC script to do this Mike? Just a loop to PRINT each > > > byte to the COM port? > > > > > > On Tue, Nov 28, 2023 at 11:45:10AM -0500, Mike Stein wrote: > > >> Why not just dump it out of the M100 directly? > > >> > > >> On Tue, Nov 28, 2023 at 9:50 AM Brian K. White <[email protected]> > wrote: > > >>> > > >>> On 11/27/23 11:48, runrin wrote: > > >>>> Do you know if it's possible to dump the original ROM using the > > >>>> programming adapter for the FlexROM 100? > > >>> > > >>> Maybe. > > >>> > > >>> There are two things to worry about and I'll just think out loud > right here. > > >>> > > >>> 1 > > >>> The programming adapter presents a pinout for a 28C256, not a 27C256 > or > > >>> mask rom. Those are only a couple wires different, but then again, > since > > >>> it's just for reading, and the read cycle is the same, you could just > > >>> tell the programmer that it's reading a 28C256 (force it, override > chip > > >>> id detection), and that won't hurt the rom. > > >>> > > >>> 2 > > >>> Pin 23. The programming adapter routes pin 27 from the programmer > (/WE > > >>> if a 28C256 were in the programmer) to pin 23 of the DIP socket, > which > > >>> is ALE on the LH535618 rom, but the flexrom board connects it to the > /WE > > >>> pin on the actual 28C256 on the board. > > >>> > > >>> I *think* what you want to do is take a DIP-28 socket and bend out > pin > > >>> 23, connect the bent-out pin 23 to pin 27, put the modified socket > into > > >>> the programming adapter and then the old rom into the modified > socket. > > >>> Then tell the programmer to read a 28C256 and ignore chip id. The > socket > > >>> is just to avoid bending the leg on the old chip. > > >>> > > >>> IE, feed /CE from the programmer to both /CE and ALE on the chip, and > > >>> don't connect anything to /WE at the programmer. > > >>> > > >>> But, at that point it's almost simpler to just make the entire > adapter > > >>> manually with two dip sockets and wires. Especially since it's a > > >>> one-off. In that case, use a 27C256 pinout and tell the programmer to > > >>> read a 27C256 instead of 28C256. > > >>> > > >>> But if your chip has any of these part numbers, then it's already > been > > >>> dumped. > > >>> > https://bitchin100.com/wiki/index.php?title=Model_and_ROM_information > > >>> > > >>> -- > > >>> bkw > > >>> > > > > -- > > bkw > > >
