techknight Posted October 11, 2014 Author Report Share Posted October 11, 2014 Fixed. RAM.pdf Quote Link to post Share on other sites
techknight Posted October 11, 2014 Author Report Share Posted October 11, 2014 CPLD code is done, now its just a matter of waiting for the PCBs, assembly, JTAG programming, and test... Quote Link to post Share on other sites
techknight Posted October 11, 2014 Author Report Share Posted October 11, 2014 Ordered the PCBs, which pretty much depleted my budget. Soon as I get some extra cash, I can order up the parts from digikey to finish the boards. Quote Link to post Share on other sites
eraser Posted October 12, 2014 Report Share Posted October 12, 2014 techknight, just in case nobody said it recently, you are awesome! Quote Link to post Share on other sites
olePigeon Posted October 12, 2014 Report Share Posted October 12, 2014 Huzzah! Too awesome. Quote Link to post Share on other sites
Paralel Posted October 13, 2014 Report Share Posted October 13, 2014 ...(send 2-self addressed mailed planes to yourself and open one up to see it and keep the other sealed until a "judge needs to see it," and keep both together)... I can say, with true and absolute certainty, that this hasn't been accepted as evidence in patent court for at least 40 years, if not longer. Quote Link to post Share on other sites
olePigeon Posted October 15, 2014 Report Share Posted October 15, 2014 I think Elfen missed a step. It has to be notarized because it needs a witness to the contents. Quote Link to post Share on other sites
techknight Posted October 16, 2014 Author Report Share Posted October 16, 2014 (edited) Here is my CPLD code in a nutshell: Chip Select/Bank Select Signals.A20, A21, A22, A23 Address line decode. The chip is hooked up between A0 and A18, or A1 to A19 if you look at the portable bus. Base RAM:0000 = No chip selected, all lines off = 0 Extended RAM:0001 - Chip 1 Select ON, Lower Bank ON = 10010 = Chip 1 Select ON, Upper Bank ON = 2 0011 = Chip 2 Select ON, Lower Bank ON = 3 0100 = Chip 2 Select ON, Upper Bank ON = 4 0101 = Chip 3 Select ON, Lower Bank ON = 5 0110 = Chip 3 Select ON, Upper Bank ON = 6 0111 = Chip 4 Select ON, Lower Bank ON = 71000 = Chip 4 Select ON, Upper Bank ON = 8 When I say Upper/Lower bank, I mean just toggling A20 high or low. Since the macintosh portable has base RAM at 512K-Word, or 1MB, I decided to break the expansion down into 1 meg chunks as well. Since the toshiba chips are 1M-Word, or 2Mbytes, just deciding where A20 is determines if I am working with the first 512kword, or the second 512kword. Edited October 16, 2014 by techknight Quote Link to post Share on other sites
techknight Posted October 17, 2014 Author Report Share Posted October 17, 2014 Quote Link to post Share on other sites
bigmessowires Posted October 17, 2014 Report Share Posted October 17, 2014 I just want to say this is very cool. I was going to offer some suggestions, but everything already looks great to me. Quote Link to post Share on other sites
techknight Posted October 17, 2014 Author Report Share Posted October 17, 2014 Your input would be appreciated. This is my first ever CPLD project. Quote Link to post Share on other sites
NJRoadfan Posted October 17, 2014 Report Share Posted October 17, 2014 (edited) You could always use a i8042 to control the A20 line. Is there any benefit to mapping the full 9MB? Isn't the 68000 limited to addressing 8MB max with the typical Macintosh memory mapping? Edited October 17, 2014 by NJRoadfan Quote Link to post Share on other sites
techknight Posted October 17, 2014 Author Report Share Posted October 17, 2014 (edited) the portable is an oddball. All RAM is mapped up until you run into ROM. Rom doesnt begin at 40 0000 as on the SE/Plus,etc. it begins at A0 0000 or 90 0000. Something like that. Why would I use an i8042? thats a keyboard controller. Edited October 17, 2014 by techknight Quote Link to post Share on other sites
NJRoadfan Posted October 18, 2014 Report Share Posted October 18, 2014 Why would I use an i8042? thats a keyboard controller. Ask IBM, seemed to work for them (It was a joke) That means the Portable can do something no other 24-bit addressing Mac can do, access more than 8MB of RAM. Neat. Quote Link to post Share on other sites
Paralel Posted October 18, 2014 Report Share Posted October 18, 2014 You think Apple meant for it to address that much memory, or it's just a fluke/oversight/they didn't care that it could be made to address that much? Quote Link to post Share on other sites
techknight Posted October 18, 2014 Author Report Share Posted October 18, 2014 the GLU allows addressing up to 5MB. a PDS card can address it all up to 9MB. Quote Link to post Share on other sites
CC_333 Posted October 19, 2014 Report Share Posted October 19, 2014 But, if I understand correctly, your card will allow more RAM in the RAM slot than the 5 MB the GLU limits it to, correct? c Quote Link to post Share on other sites
techknight Posted October 19, 2014 Author Report Share Posted October 19, 2014 i hope so. Quote Link to post Share on other sites
CC_333 Posted October 19, 2014 Report Share Posted October 19, 2014 By way of some special pass through connector in the ROM slot that breaks out the needed extra address lines? How will that be done, exactly? Or did you solve that by doing all the encoding/decoding/etc. on the card? I will definitely be interested in one when it's ready. ...And a new back lit ribbon cable for the LCD (or a decent repair of the current one). c Quote Link to post Share on other sites
techknight Posted October 20, 2014 Author Report Share Posted October 20, 2014 Youll see.... the address decoding and chip select is all done on the CPLD thats on the RAM card. I carried a tap for DTACK, and address strobe/AS. that way, I can just bring those 2 wires over to the adjacent slot to get full decode. Quote Link to post Share on other sites
trag Posted October 20, 2014 Report Share Posted October 20, 2014 Eagerly awaiting the test results -- and I don't even have a Portable. I just have pent up project pressure (PUPP). I had this project in mind for years. It's wonderful to see it get done even if I'm not involved (other than pulling a box out of the attic). Quote Link to post Share on other sites
techknight Posted October 20, 2014 Author Report Share Posted October 20, 2014 Well, i am just waiting on PCBs. Plus waiting to refill my expendable budget to get parts from digikey. Quote Link to post Share on other sites
aplmak Posted October 21, 2014 Report Share Posted October 21, 2014 Techknight.... I don't know if this helps but I just found an 8MB PDS RAM card in my collection!!!!!!!! This gives you the full 8MB.. It's plugged into a 5126.. I don't know if there is more if you plug it in a 5120 but I will try... Look at the pics... It says Sunland Micro Systems Matt Quote Link to post Share on other sites
aplmak Posted October 21, 2014 Report Share Posted October 21, 2014 Same total ram on 5126 and 5120... But curious... Could I put in the PDS ram and a regular RAM card?? Or will it just see the max of 8MB?? Matt Quote Link to post Share on other sites
Paralel Posted October 21, 2014 Report Share Posted October 21, 2014 (edited) It's one or the other, if I'm not mistaken. The max is 9 MB, not 8, according to the legwork that TN has done. Edited October 21, 2014 by Paralel Quote Link to post Share on other sites
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