>Date: Mon, 13 Jan 2003 08:19:39 -0800 >From: Gamba <[EMAIL PROTECTED]> > >>This seems to make it much more difficult to adapt the IIci ROMs to >>the SE/30. >>Jeff Walther > >I have seen 3 variations of the SE/30 rom simms.
>On two of the three I was able to identify the base part number of the chips: >1..Apple part numbers HN62321 series.. > base ROM part number HN6231, which is (128K X 8). > The package is SOIC-32. > >Correction, the package on these is PLCC-32, not SOIC-32 >Assuming the IIci ROMS are (128K X 8), you could copy the code from them, >into new ROM chips (1..) above. Yes, the IIci ROMs are 128K X 8 in a DIP package. Most any PLCC-32 128K X 8 chip should work. All the ones I've seen have the same pinout with the variation being only in WE and VPP or the analogous pins. Since the device will be used for read-only once it is on the SE/30 ROM module, the placement of above pins shouldn't matter as long as they aren't tied active. I have a bunch of Atmel AT49F010 on hand, which is what I plan to use. I guess the only thing that could trip this up, is if there is some significant variation in timing or wave-form from the older OTP EPROMs. >But of course you would need that particular SE/30 ROM simm. >If I have an extra and if above makes sense, you can have it. That is a very kind offer. Number 1 above is the one that would make this project work if you have one available. I would be happy to send you this SE/30 ROM module in exchange. Shall I contact you off list? >>Assuming the IIci ROMS are (128K X 8), > >And I just checked, they are (128K X 8). >So, because the 27C010 is EPROM instead of Mask ROM, seems like you could >just copy the code from the IIci chips into new 27C010s and put those >27C010s into the appropiate SE/30 ROM simm. Apple appears to have used One Time Programmable EPROMs for a fair number of these modules. But any non-volatile storage device of the correct capacity and pinout will probably work. The pinouts of Mask ROMs, EPROMs, EEPROMs and Flash of the same capacity, organization and package type tend to be the same regardless of the underlying technology. So, for example, while the mask ROMs in Apple's 7200,. x500 and x600 machines might be a Macronix MX23C8100 or equivalent Sharp or Samsung KM23C8100 ROM, one can substitute an Atmel AT49F8192-90RC or Hyundai HY29F800BG Flash memory if it is programmed with the appropriate code. >A handy URL that I ran across is ><http://www.spies.com/~arcade/schematics/ROMref.txt> That's very cool. I don't have any arcade games, but I'm glad someone is keeping those old things going. I really liked some of the old ones. Gamba, thanks again for the information. Please let me know about the ROM module. Jeff Walther -- Compact Macs is sponsored by <http://lowendmac.com/>. Support Low End Mac <http://lowendmac.com/lists/support.html> Compact Macs list info: <http://lowendmac.com/lists/compact.shtml> The FAQ: <http://macfaq.org/> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive:<http://www.mail-archive.com/compact.macs%40mail.maclaunch.com/> --------------------------------------------------------------- >The Think Different Store http://www.ThinkDifferentStore.com ---------------------------------------------------------------
