wtm@neoucom.UUCP (Bill Mayhew) (07/04/86)
///// Hi, I just got in an Apple 2E/enhanced computer that is replacing an older vanilla Apple 2E in an lab application that we are running. The application uses an ADC driven by interrupts to look at a process every 100 cpu clocks. Everything was fine when we used regular Apple 2s and 2Es. Now our application bombs, as the monitor ROM (under DOS 3.3) seems to do something that regularly shuts off interrupts for 250-300 uS. I haven't received any tech info on what goodies the enhanced version has yet. (I thot it was just a new CG ROM with the mouse characters, but they must've reworked the EF and/or CD ROMS too). For my application, I don't give a hoot about the mouse support. What I was wondering, does anybody know if I can de-enhance my computer by putting old ROMs in it? Anybody happen to know if the EF and CD ROMs can be replaced with 2764s? It would save us a lot of time to burn our own. Thanx in advance to any respondants. Bill Mayhew Division of Basic medical Sciences N. E. Ohio Universities' College of Med. 4209 SR 44 Rootstown, OH 44272 USA (216) 325-2511 ...!allegra!neoucom!wtm (or something like that?)
kamath@reed.UUCP (Sean Kamath) (07/06/86)
In article <222@neoucom.UUCP> wtm@neoucom.UUCP (Bill Mayhew) writes: >///// >Hi, > > I just got in an Apple 2E/enhanced computer that is >replacing an older vanilla Apple 2E in an lab application that we >are running. The application uses an ADC driven by interrupts to >look at a process every 100 cpu clocks. > > Everything was fine when we used regular Apple 2s and 2Es. >Now our application bombs, as the monitor ROM (under DOS 3.3) seems >to do something that regularly shuts off interrupts for 250-300 uS. > Hmmmm. Strange. The new roms are actually much better about letting interrupt through. The old roms would turn off interrupts for too long in 80 column mode, thereby loosing characters at 1200 baud or above. I wonder if it's because the new interrupt routines push the a reg on the stack. No, I guess it stil shoves it in $45 as well. Frankly, I'd figure out where it bombs specifically. The new roms are worth it. I think so, anyway. > I haven't received any tech info on what goodies the >enhanced version has yet. (I thot it was just a new CG ROM with >the mouse characters, but they must've reworked the EF and/or CD >ROMS too). Like I said, the roms have better interrupt handling. They also read lower case, you can search for a address, value or character in memory, as well as input characters. The mini assembler is also there. It's just plain cooler :-) The only thing they screwed up on royally was not putting the new op-codes into the disassembler...:-( But I got a fix for that:-) > > For my application, I don't give a hoot about the mouse >support. What I was wondering, does anybody know if I can >de-enhance my computer by putting old ROMs in it? Anybody happen >to know if the EF and CD ROMs can be replaced with 2764s? It would >save us a lot of time to burn our own. Yes, the roms are staight 2764's. No problem. Drop 'em right in. Leave the 65c02, though. And maybe the CharGen rom. > > Thanx in advance to any respondants. > >Bill Mayhew >Division of Basic medical Sciences >N. E. Ohio Universities' College of Med. >4209 SR 44 >Rootstown, OH 44272 USA (216) 325-2511 >...!allegra!neoucom!wtm (or something like that?) ________________________________________________________________________________ Sean Kamath UUCP {ihnp4,decvax,ucbcad,hplabs}!tektronix!reed!kamath US Snail: Box 395 Reed College, Portland, OR 97202 (503) 239-7458
ranger@ecsvax.UUCP (Rick N. Fincher) (07/07/86)
> Everything was fine when we used regular Apple 2s and 2Es. > Now our application bombs, as the monitor ROM (under DOS 3.3) seems > to do something that regularly shuts off interrupts for 250-300 uS. > > support. What I was wondering, does anybody know if I can > de-enhance my computer by putting old ROMs in it? Anybody happen > to know if the EF and CD ROMs can be replaced with 2764s? It would > save us a lot of time to burn our own. > This is an odd problem since the manual for the new ROMs claims that the new monitor does not disable interrupts for an extended period. The old ROMs would disable interrupts for extended periods while 80 col screen updating was going on because the old ROMs couldn't tolerate interrupts except in main memory. The new Roms support interrupts in Aux memory by saving the memory state in effect when the interrupt occurred and setting the machine to a known state before going to the interrupt handling routine. This shouldn't take anywhere near 250-300 usecs though. With the new ROMs the accumulator is no longer saved in location $45, it is put on the stack instead. This location is used by DOS 3.3 and the monitor so storing the accumulator here trashed things. Your application probably uses a modified version of DOS to avoid this proble problem. If your application is looking for the contents of the accumulator at $45 it will not work with the new ROMs. You should have gotten the manual "About your enhanced Apple IIe: Programmers Guide" when you upgraded, if not see you dealer for a copy. It will help you modify your code to work with the new interrupt handler. If you are using commercial software call the manufacturer and see if they have a new version. If you really want the old ROMs back, see Don Lancaster's column "Ask the Guru" in Computer Shopper. From about January to May of this year he had a series of articles on installing both sets of ROMs in your IIe and switching between them. He had detailed in- structions on burning ROMs for the Apple. (Sorry I can't be more precise on the dates of those articles, but you can call Don for help, his number is in his column). Rick Fincher