I won't begin to know how to make a card, but if any of you decides to make some Grey scale adapters please let me know and I'll pitch in, i would love to get my hands on one.
I read somewhere that you can use a Mac IIFX ROM Simm. The screen will show some lines for a few seconds during start up but that is the only difference between the Mac IIsi ROM SIMM and the IIfx. I remember reading, most of the ROM SIMMS for the Mac IIsi are not removable, only a few are and that is why it is easier to find a Mac IIFX ROM SIMM. Hope this helps Abel On Mon, Mar 2, 2009 at 3:04 PM, Derek Morton <[email protected]> wrote: > > I seem to recall having this conversation in a previous thread a few > years ago (was Stuart Bell involved?). Perhaps the best solution is > to make more than a single boIard design (ROM SIMM, XCeed Grey Scale > adapter, PDS adapters, etc) and run them through as a flat. When I > did board design (in a past life), we typically got 5 flats as a > minimum run (1 flat costs the same as 5) with each flat being > approximately 64 square inches of material... Tooling is where your > money goes. The negative is that all your boards need to be the same > thickness, so your grey scale adapter would also end up as a .047 > (3/64"). Not really an issue except the board is less stiff. Keep > in mind that if you need to go multi-layer, the costs go up as well. > I have used the proto services a few times, the boards worked, but I > was none too impressed by the quality of the actual board... Things > didn't line-up properly... Tracks were connected, but there were > often slight offsets where track segments met. But for the price... > > Is it really worth doing except for the intellectual challenge? Who > knows? Unless enough people agreed to buy, or enough use was found > for the flat (to amortize the cost over multiple projects), it would > make this hobby quite expensive... Although judging by the prices on > eBay now... It already is. > > Derek > > On Mar 2, 2009, at 10:09 AM, trag wrote: > > > > > > > > > On Mar 1, 6:58 am, Raymond Ingles <[email protected]> wrote: > >> On Sat, Feb 28, 2009 at 11:12 PM, Derek Morton > >> <[email protected]> wrote: > > > >>> Couldn't we just strip the ROMs from a IIsi and move them to > >>> a ROM simm (make our own)? > >> > >> Should be doable, given the parts. > > > > The place where this project bogs down is at the circuit board for the > > ROM SIMM. There are three basic choices: > > > > 1) Make your own: If you aren't already set up to do this, it will > > cost you more than the other alternatives. You can trade time for > > money to an extent, so you might be able to do it with less actual > > cash expenditure, if your time has no value. > > 2) Buy a few using a commercial proto-type service: Printed circuit > > board services typically have two services relevant to us hobbyists. > > One of those is proto-typing. Send them your design and for $30 - > > $50 per board they'll send you a few copies. There is usually a > > minimum purchase that makes this outlay $100 - $200 for 2 - 4 boards. > > However, most proto services are not available for this project > > because the board specifications in proto service are very limited and > > one of the limitation is .062" thick board only. The Mac II family > > ROM SIMM is .050" or .047" thick. > > 3) Order 200 using a commercial board fabrication service: The other > > board service relevant to us hobbyists is just plain old printed > > circuit board fabrication. If you order about 200 printed circuit > > boards to serve as ROM SIMMs in the Mac II family, the cost will be in > > the neighborhood of $600, or $3 per board. $3 per board is very > > affordable. However, do you think you could ever sell 200 of them? > > 100? How about 50? > > > > Keep in mind these are just the circuit boards. You must still obtain > > ROM chips and solder them to the boards. > > > > This is the main difficulty in making ROM SIMMs. I have a circuit > > board design ready to go--although on reflection there are some > > changes I would make now--but the above economic realities mean that > > I'll probably never have it fabricated. > > > > Jeff Walther > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/vintage-macs?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
