If you have a spare 24pin IC socket, bend out pin 18 to isolate it and put it between the 2316 and your programmer socket, and you might be able to read the H5 - H7 ROMs that way; if not, try connecting that 2K resistor between the bent-out pin 18 and pin 24. Pleasant dreams ;-) m ----- Original Message ----- From: "MikeS" <dm561@torfree.net> To: <cbm-hackers@musoftware.de> Sent: Friday, May 13, 2011 3:06 PM Subject: Re: PET 2001 fix Part 3 - RAM/ROM board etc. > The ROM numbers and locations look good, but I would expect H1 to H4 to > all > read OK. Why not try putting your respective 2716 equivalents into H1 and > H3, leaving the originals in H2, 4, 5, 6 and 7. > > BTW, can you program 2532s and do you have any? > > m > > ******************* > > ----- Original Message ----- > From: "Philip Lord" <random6000@mac.com> > To: <cbm-hackers@musoftware.de> > Sent: Friday, May 13, 2011 2:39 PM > Subject: Re: PET 2001 fix Part 3 - RAM/ROM board etc. > > > Don't worry, I'm not insulted at all. > > I believe I have the following ROM set (I'll double check in the morning): > > Location Part Number > ------------------------------ > H1 901447-09 > H2 901447-03 > H3 901447-05 > H4 901447-06 > H5 901447-02 > H6 901447-04 > H7 901447-07 > > And I have followed the above convention for placement. 09, 03, 05, 06, > 02, > 04 and 07 in that order. > > When I read the original ROMs in my burner I got the following: > > H1 - full of 00's > H2 - good > H3 - full of FF's > H4 - good > H5 - full of FF's > H6 - full of FF's > H7 - full of FF's > > so is it possible that H5, H6, ad H7 were not read correctly by my > programmer. H3 also shows full FF's, but H1 read as full 00's...Could it > be > that H1 is the only one that is indeed dead? > > I'll remove the two 6520 PIAs, and I'll take a look on VCF for the > voltages > thread. > > Thanks again for your time. > > Phil > > On May 14, 2011, at 3:17 AM, MikeS wrote: > >> Sorry, emails crossed and you answered my question before I asked it ;-) >> >> A crude way would be to measure the voltage on the various 6502 pins, >> especially the Reset, Sync and Ready pins. >> >> There's a thread on VCF right now that might be relevant. >> >> m >> >> ----- Original Message ----- From: "Philip Lord" <random6000@mac.com> >> To: <cbm-hackers@musoftware.de> >> Sent: Friday, May 13, 2011 1:55 PM >> Subject: Re: PET 2001 fix Part 3 - RAM/ROM board etc. >> >> >> Thanks André, >> I only have limited tools. Logic probe, eprom burner and multimeter. >> >> I'll have to snag the keyboard out of my working pet to try the 'LOAD' >> test. >> What other ways can I test if the CPU is working? >> >> Phil >> >> >> On May 14, 2011, at 2:39 AM, André Fachat wrote: >> >>> >>> >>> Looking at the further discussion, you are concentrating on the video >>> part, but is the CPU actually running ok? I didn't see that, may be I >>> overlooked it. But you mentioned burning new ROMs as the original ones >>> were dead. >>> >>> If the cpu is not running ok, this could explain the random characters >>> on >>> one side and also the "snow", as some random code would not wait for the >>> vertical retrace when writing to the screen memory. >>> >>> Did you try checking for example with a tape and typing LOAD and >>> pressing >>> the Play button that the tape starts turning? >>> >>> I'd concentrate finding why the CPU isn't working and looking at the >>> video later. >>> >>> André >>> >>> >>> -------- Original-Nachricht -------- >>>> Datum: Fri, 13 May 2011 19:27:34 +0200 >>>> Von: "André Fachat" <afachat@gmx.de> >>>> An: cbm-hackers@musoftware.de >>>> Betreff: Re: PET 2001 fix Part 3 - RAM/ROM board etc. >>> >>>> >>>> -------- Original-Nachricht -------- >>>> >>>>> So now I have a screen of random and slightly deformed characters >>>>> (seems >>>>> like the same or similar character layout on each start up though), >>>>> with >>>> a >>>>> pixel flicker through them. I've put pics and a short video up on the >>>> same >>>>> page here: >>>> >>>> Sorry to chime in so late only. The pixel flicker might be from the >>>> fact >>>> that the CPU accesses the video RAM. The oldest PETs had video RAM with >>>> max >>>> 1MHz operation only, so when the CPU accesses the video RAM the video >>>> display presented "snow". The CPU controlled access to the video RAM by >>>> sampling >>>> the vertical retrace on a VIA pin (VIA Port B ($e840, 59456), bit 5). >>>> This >>>> could relate to the fact that characters seem stable when the machine >>>> resets (switching off?) >>>> >>>> Maybe the VIA has a problem here? >>>> >>>> On a side note: the fact that switching this vertical retrace off >>>> resulted >>>> snow, but also faster screen output - no wait anymore - a certain POKE >>>> was >>>> found to make that VIA input pin an output - accidentally destroying >>>> some >>>> newer models, the "killer poke". >>>> >>>> André >>>> >>>> -- >>>> NEU: FreePhone - kostenlos mobil telefonieren und surfen! >>>> Jetzt informieren: http://www.gmx.net/de/go/freephone >>>> >>>> Message was sent through the cbm-hackers mailing list >>> >>> -- >>> Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir >>> belohnen Sie mit bis zu 50,- Euro! https://freundschaftswerbung.gmx.de >>> >>> Message was sent through the cbm-hackers mailing list >> >> >> Message was sent through the cbm-hackers mailing list >> >> Message was sent through the cbm-hackers mailing list > > > Message was sent through the cbm-hackers mailing list > > > Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2011-05-13 20:00:24
Archive generated by hypermail 2.2.0.