This brings a question to mind. The Tandy 200 and NEC 8201 (and 8300) have multiple banks. Since the 27c512 is identical to the 27c256 ROM with the exception of pin 1 which is for address 15. Could a 27C512 be inserted with pin 1 bent to stick out to the side and then a wire run from pin 1 to the enable pin of bank 2? So switching banks also switches OptRoms? I have read an article about installing a switch to do this but I wasn't sure if this could be done by taping the existing hardware. Kurt
On Tue, Sep 11, 2018, at 9:36 AM, Mike Stein wrote: > > Another simple approach that's often used is to have an adapter with > an (E)EPROM large enough to hold several ROM images and a physical (or > logical) switch to select among them (essentially what my adapter > does, but with only one OptROM image).> > Unfortunately there's very little vertical clearance in these babies > so there's not much room to use the old trick of stacking several > chips with the select lines brought out the side. I haven't looked at > my T102 but in the M100 there is enough room for one piggy-backed > chip which would give you at least three 32KB OptROM images, but it > does lift the keyboard slightly unless you remove the socket; > depending on the socket used you might also gain some clearance if > you trim the IC leads.> > Another approach to using several and/or larger ROMs is to make a > little board that puts the chips upside down in the space beside the > system ROM; as a matter of fact the plan with this prototype board > was to add another RAM or ROM socket beside the existing one:> > > > > > ----- Original Message ----- > From: "Greg Swallow" <gswal...@mchsi.com> > To: <m...@bitchin100.com> > Sent: Tuesday, September 11, 2018 9:34 AM > Subject: Re: [M100] call for programs and games > > > Multiple ROMs would be easy enough with a REX. Of course if the REX > > goes, you could be out of luck.
