senior_falcon Posted September 22, 2017 Share Posted September 22, 2017 (edited) In XB there are 24 bytes from >FFE8 to >FFFF that are not used by Extended BASIC. Why are these bytes reserved? Is there any reason they cannot be used as a mailbox to pass information between different XB programs? Edited September 22, 2017 by senior_falcon Quote Link to comment Share on other sites More sharing options...
RXB Posted September 22, 2017 Share Posted September 22, 2017 Many years ago I read something about >FFE8 to >FFFF being assigned to a TI memory expansion concept mentioned in the XB ROM source that I lost. It did not explain anything about it or how it worked. But it did mention a DEBUGGER CARD being used to demo the use. 1 Quote Link to comment Share on other sites More sharing options...
senior_falcon Posted September 22, 2017 Author Share Posted September 22, 2017 It was reserved for some purpose and that makes as much sense as anything. Load interrupt uses >FFFC and >FFFE, but that's the only use I can see in that area. Quote Link to comment Share on other sites More sharing options...
+acadiel Posted September 23, 2017 Share Posted September 23, 2017 Corcomp Load Interrupt Card. I had modded it a while back to remove the 5V from the sidecarts I was dumping. LOL. Power up, go into Mini Mem, give the side car 5V, and the dump the DSR and 32K space :-) If you used it as intended, and pressed the button, it would go to >FFFC and jump to that address’ contents, I believe. 1 Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted September 23, 2017 Share Posted September 23, 2017 I think the RAM Trap used that space as well. . . Quote Link to comment Share on other sites More sharing options...
+InsaneMultitasker Posted September 23, 2017 Share Posted September 23, 2017 Millers Graphics documentation doesn't show any use for that space. I wonder if the space below the load interrupt vector was used in an older version of XB, or for some specific future function that was never implemented. I use memory from >A000 up as my mailbox space in many programs. For example, my BBS software uses >a000->a500 (just over 1k) for various buffers and information passing. Since upper memory usage is determined by program size plus numeric variable run-time space, it is relatively easy to ensure my program 'modules' never cross into that area. 1 Quote Link to comment Share on other sites More sharing options...
ralphb Posted September 24, 2017 Share Posted September 24, 2017 According to Thierry: "As mentionned above, the five registers of the floppy disk controller map in the memory area >FFF0-FFFF. The addresses are different for read operations than for write operations". Quote Link to comment Share on other sites More sharing options...
senior_falcon Posted September 24, 2017 Author Share Posted September 24, 2017 According to Thierry: "As mentionned above, the five registers of the floppy disk controller map in the memory area >FFF0-FFFF. The addresses are different for read operations than for write operations". That must be a misprint. The assembly code examples on that page all show the registers stored at >5FF0 to >5FFF. Which makes sense because the disk system will work without memory expansion. 1 Quote Link to comment Share on other sites More sharing options...
+Lee Stewart Posted September 24, 2017 Share Posted September 24, 2017 According to Thierry: "As mentionned above, the five registers of the floppy disk controller map in the memory area >FFF0-FFFF. The addresses are different for read operations than for write operations". I always wondered why TI Forth (and fbForth by inheritance) stayed clear of >FFF2 – >FFFF. The 82-byte Terminal Input Buffer (>FFA0 – >FFF1) is the highest memory used. Perhaps this is the reason—or not (per Harry's post above). ...lee [Edits in this color.] Quote Link to comment Share on other sites More sharing options...
+Lee Stewart Posted September 24, 2017 Share Posted September 24, 2017 That must be a misprint. The assembly code examples on that page all show the registers stored at >5FF0 to >5FFF. Which makes sense because the disk system will work without memory expansion. That makes even more sense in light of the table immediately following that statement. When I first read it, that disparity puzzled me. ...lee Quote Link to comment Share on other sites More sharing options...
senior_falcon Posted September 24, 2017 Author Share Posted September 24, 2017 That makes even more sense in light of the table immediately following that statement. When I first read it, that disparity puzzled me. ...lee Plus, if you do a search for >5FF it occurs 41 times on that page with instructions like: MOVB @>5FF0,R6 Read FDC status register RDY MOVB R0,@>5FF8 Send command to FDC command register etc. Quote Link to comment Share on other sites More sharing options...
Airshack Posted September 25, 2017 Share Posted September 25, 2017 Millers Graphics documentation doesn't show any use for that space. Which Millers Graphics docs? Link? Sent from my iPhone using Tapatalk Pro Quote Link to comment Share on other sites More sharing options...
+InsaneMultitasker Posted September 25, 2017 Share Posted September 25, 2017 (edited) Which Millers Graphics docs? Link? Sent from my iPhone using Tapatalk Pro I thought I typed the reference. Ah well. It was Millers Graphics The Smart Programmer monthly newsletter. I was reading the real, printed document. Edit: Just got back home; the memory layout I looked at is in the March 1984 issue. Edited September 25, 2017 by InsaneMultitasker Quote Link to comment Share on other sites More sharing options...
+Lee Stewart Posted September 25, 2017 Share Posted September 25, 2017 Which Millers Graphics docs? Link? I thought I typed the reference. Ah well. It was Millers Graphics The Smart Programmer monthly newsletter. I was reading the real, printed document. ...on the WHTech site under ..\magazines\smartprogrammer. ...lee 1 Quote Link to comment Share on other sites More sharing options...
RXB Posted September 25, 2017 Share Posted September 25, 2017 (edited) I always wondered why TI Forth (and fbForth by inheritance) stayed clear of >FFF2 – >FFFF. The 82-byte Terminal Input Buffer (>FFA0 – >FFF1) is the highest memory used. Perhaps this is the reason—or not (per Harry's post above). ...lee [Edits in this color.] Hmm I told you guys it was for a future expansion paged memory created by TI, but never made it past set up stage. It was mentioned on the side notes handwritten from my old XB ROM source I got from TI. Edited September 25, 2017 by RXB 1 Quote Link to comment Share on other sites More sharing options...
Airshack Posted September 26, 2017 Share Posted September 26, 2017 It was mentioned on the side notes handwritten from my old XB ROM source I got from TI. Hey Rich, Are these handwritten notes scanned and archived anywhere? I can't remember reading this anywhere else? -j Sent from my iPhone using Tapatalk Pro Quote Link to comment Share on other sites More sharing options...
RXB Posted September 27, 2017 Share Posted September 27, 2017 (edited) Hey Rich, Are these handwritten notes scanned and archived anywhere? I can't remember reading this anywhere else? -j Sent from my iPhone using Tapatalk Pro I hand typed in all 5 inches of pages of the source including the handwritten notes and uploaded them to GENIE and the KEEP and other BBS. I also mailed copies to numerous people after they asked for them on DISKs. My computer SCSI Hard drive crashed and I lost all copies but to make matter worse I loaned the original hard copy to a buddy that lost them in a Portland Oregon flood. So no unless someone has them from these copies I made we no longer have this source. Edited September 28, 2017 by RXB 1 Quote Link to comment Share on other sites More sharing options...
senior_falcon Posted September 27, 2017 Author Share Posted September 27, 2017 That's discouraging! Do you still have the original hard drive? I had a hard drive crash and lost some pictures. I was lucky-it was the circuit board on the drive that failed. I got an identical drive on ebay and swapped out the board and was able to retrieve the pictures. 1 Quote Link to comment Share on other sites More sharing options...
Airshack Posted September 27, 2017 Share Posted September 27, 2017 Wondering if those files are sitting around on some internet archive somewhere? Sent from my iPhone using Tapatalk Pro Quote Link to comment Share on other sites More sharing options...
RXB Posted September 28, 2017 Share Posted September 28, 2017 That's discouraging! Do you still have the original hard drive? I had a hard drive crash and lost some pictures. I was lucky-it was the circuit board on the drive that failed. I got an identical drive on ebay and swapped out the board and was able to retrieve the pictures. Sorry no I have extensive software on the Mac and Windows side to recover drive data and it was totally gone or corrupted beyond recovery. Quote Link to comment Share on other sites More sharing options...
RXB Posted September 28, 2017 Share Posted September 28, 2017 Wondering if those files are sitting around on some internet archive somewhere? Sent from my iPhone using Tapatalk Pro I have repeatedly asked the community to search archives for it including WHT FTP that had a copy uploaded to it.....no replies. Quote Link to comment Share on other sites More sharing options...
sparkdrummer Posted September 28, 2017 Share Posted September 28, 2017 Any idea of the file names Rich? Quote Link to comment Share on other sites More sharing options...
RXB Posted September 28, 2017 Share Posted September 28, 2017 Yea all of them named XBROMSRC1 and 2 or XBROMS1 and 2. 1 Quote Link to comment Share on other sites More sharing options...
sparkdrummer Posted September 28, 2017 Share Posted September 28, 2017 Well, I looked in all my stuff for those files - I came up empty. I came across some files that say IMYXB3 text and dsks - which are in a folder entitled RXB v2001 source - I don't suppose these are what you're looking for. Quote Link to comment Share on other sites More sharing options...
RXB Posted September 28, 2017 Share Posted September 28, 2017 (edited) Well, I looked in all my stuff for those files - I came up empty. I came across some files that say IMYXB3 text and dsks - which are in a folder entitled RXB v2001 source - I don't suppose these are what you're looking for. Sorry no this was done just before I released RXB 2001, at the time I think it was RXB version 5.55 released. Edited September 28, 2017 by RXB Quote Link to comment Share on other sites More sharing options...
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