you can build a Quad if you want.. it's up there. no instructions however.
On Thu, Jun 16, 2016 at 11:50 AM, Stephen Adolph <[email protected]> wrote: > that rex does not work. I will pull it down. it was for visibility only.. > > On Thu, Jun 16, 2016 at 11:26 AM, Brian White <[email protected]> wrote: >> Crap I'm sorry Mike! >> >> But the question was about an option rom not the main rom. A dip28 chip just >> about fills all available volume in the option rom socket. If you need to >> add anything else to the board, it will be difficult. There is a little room >> on the edge, and there is about 1/10" of height across the bottom. Can you >> make a 27C256 both usable and re-programmable within those constraints? >> Would it need a jumper and resistor like 28C256 does? >> >> As for rex, now that Stephen has put a version of rex up on osh park I plan >> to try to build one and we'll see. I've already ordered a set. >> >> If it costs more in parts, that's a potential reason. >> >> If it's more difficult to build, then that is a potential reason. It was >> easy to do the soic option rom, and the through-hole plcc socket main rom, >> and your own dip28 main rom. The qfp legs are finer than soic, but still >> look doable, but that tsop chip...well we'll see, maybe it's fine. >> >> If it requires special software or hardware to program the cpld, that is a >> protential reason. I can program an eprom using small purely open source >> software and $30 hardware. For the fpga in the MISE, I got a ByteBlaster for >> $25 and the programming software was free, but it was a large download of >> proprietary software, and was not easy to get working on the linux netbook I >> like to use for stuff like this where possible. I don't know yet what it >> takes to program the cpld on the rex, but I'm guessing it will be doable and >> within reason like those examples. >> >> If there is any software incompatibility, that is a potential reason. >> >> If it conflicts with the option rom socket, then that is a potential reason. >> >> On Jun 15, 2016 10:41 PM, "Mike Stein" <[email protected]> wrote: >> >> So it's become *Stephen's* M100ROM board now? ;-) >> >> I don't see any reason myself why you couldn't make a re-programmable Option >> ROM adapter using a 27C256 EPROM but I'm not going to get into another >> discussion; I am curious though why, with the various other options >> including REX, you'd want one? >> >> Personally, I still think an Option ROM adapter using a RAM chip would be >> nice; I wonder if the FigTronix one could be adapted... >> >> m >> >> ----- Original Message ----- >> From: Kurt McCullum >> To: Model 100 Discussion >> Sent: Tuesday, June 14, 2016 2:30 PM >> Subject: Re: [M100] Adapter Board >> >> Thanks for all the information. The list is once again a wealth of >> knowledge. I'll look into the other boards. >> >> Kurt >> >> >> On Tuesday, June 14, 2016 10:18 AM, Brian White <[email protected]> wrote: >> >> >> A 27C256 is problematical in the option rom socket because you can't >> reprogram it once you solder it. Or at least it would be pretty hard to >> squeeze the couple extra components to handle the Vpp pin so that it is tied >> to Vcc (or gdn or no-connect, I forget what it needs right now, other than >> that it should *not* be connected to any of the socket legs) during normal >> run-time operation, but not tied to Vcc and instead *is* routed to an edge >> contact for programming. The 28C256 board can do it because the chip is SOIC >> package and there is physically room for the parts. >> There is no such thing as a SOIC 27C256, or at least not an erasable one. >> Burning and soldering a chip as a one-way trip is not really hobbyist >> friendly. You risk wasting $6 chips and having to de-solder, clean, and >> resolder chips on the board for every mistake or testing another rom. >> It's different if you're producing 100 copies of the same thing to sell. You >> don't care about re-writing then. But in that case you have the resources to >> just whip up your own new board any time you want. A few different similar >> board designs are public that you can download and copy, and even the cad >> software is free (kicad). Edit and upload to osh park and order as set for >> $6. >> But I suggest just use the SOIC v2.0 28C256 board. And get the option rom >> programming adapter v2 at the same time. And some singlenrow machined round >> pin headers for the programming adapter. >> Or use the m100 board (Stephen's, not FigTroniX) and use the option rom >> feature on that. It goes in the main rom socket inside, not in the option >> rom socket, and it can provide both a main and option rom in one uv-erasable >> 28 pin dip 27C512. >> -- >> bkw >> On Jun 14, 2016 11:42 AM, "Stephen Adolph" <[email protected]> wrote: >> >> ah sorry I missed that. yah it is for main rom socket. not optrom. >> but it can provide optrom. >> >> On Tue, Jun 14, 2016 at 11:35 AM, Kurt McCullum <[email protected]> >> wrote: >>> Would it just need to be cut down to fit into a 102 or 200 optrom slot? I >>> suppose since the 200 has a regular socket for its main ROM it might work >>> as >>> is. >>> >>> >>> >>> On Tuesday, June 14, 2016 8:20 AM, Stephen Adolph <[email protected]> >>> wrote: >>> >>> >>> the M100ROM board supports 27C256.. >>> >>> On Tue, Jun 14, 2016 at 10:58 AM, Kurt McCullum <[email protected]> >>> wrote: >>>> There have been a few new adapter boards for the OptRom slot of the >>>> 100/102/200. I notice that none of them support a standard 27C256 EPROM. >>>> I >>>> know these boards used to be available, along with the wrap around >>>> flexible >>>> circuit boards used by Traveling Software. Does anybody know of an >>>> OSHPark >>>> design that exists? >>>> >>>> Kurt >>> >>> >> >> >>
