Posted By
Paradroid90
on 2014-09-04
03:30:20
|  New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Hello, Everyone
Hope you are all well. Although I have been relative newbie when it comes to the plus4, I have been in the retro community, mainly in the C64 scene for the last couple of years. Recently I acquired a plus4 that needed some TLC, Now the work has been completed with a SD2IEC installed internally I am looking forward to see what the Plus4 scene has to offer  . It is great to see the homebrew scene is thriving, and please keep up the good work. I must admit I have come across a couple of issues with loading certain .d64 and .prg files. Either from my 1541 disk drive or my SD2IEC certain images are refusing to load. The demo Threeve (Which I love by the way ) is refusing to load from my 1541 or SD2IEC. I have tried every image on the plus4 world and the pouet with no success  . Is it I am doing something wrong or is this a known glitch? Thanks for your support in advance everyone.
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Posted By
MIK
on 2014-09-04
13:18:27
 | Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Hi and a warm welcome.
I still don't have one of these drives yet so can't comment as to why, however...
Some Demo's can be 1551 only meaning they will only run on that drive or under emulation so it's always worth asking if you have no luck. Hopefully some one knows.
There might be the odd .PRG file still out there that has been saved wrong meaning it will be one bite out in memory once loaded so won't work. This is not something an emulator worries about and why they do work on them. On the real machine a small handful of say 12k games may of been saved from $1000-$4000 which is a common mistake which back in the early days you would see a lot when it should of been saved from $1001-$4000.
In cases like this if a .PRG fails to work once loaded from Basic then after a reset, enter the Machine code MONITOR,
M(SHIFT)O
and then type: L"FILE NAME",8
Type X to return back to Basic once it's loaded and hopefully typing RUN will make it work.
If you ever find a prg like this then load it in to Yape, it will say where it is loaded in memory, (from $XXXX and too $XXXX), then just re-save it where Yape says it should be saved from and too. Yape will want to save from $1001 correcting the mistake.
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Posted By
Paradroid90
on 2014-09-04
13:39:16
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Thanks for the warm welcome MIK, and you support has been great thank you. I tried running the Threeve prg file via the monitor as suggested (Thanks for that tip, never knew that ) but still crashed .
I have never used Yape before but I will give this a bash with the Threeve prg file and see where that takes me.
Any further suggestions would be appreciated
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Posted By
Paradroid90
on 2014-09-04
14:38:37
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Mmmmmmmmm still getting the same issue when I re-saved the prg file to the address requested....I will try another prg file to see if I can some success
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Posted By
JamesC
on 2014-09-04
16:44:09
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
The copy of Threeve on Plus/4 World works correctly in Yape. It even works under NTSC -- music is a little faster than PAL mode, but it displays properly.
At this point I'm wondering if there was a download problem in your copy of the program file. Redownload it from this site, verify that it works in Yape, then move to your SD card for testing on the real machine.
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Posted By
Paradroid90
on 2014-09-05
02:21:51
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Thanks for the feedback James, All of the .prg's run fine in Yape I have found. Re-save with the address given by Yape and it still will not load? Like I say Threeve is not the only .prg that will not load. Laser Squad, Elite+4 (Although Elite+ will run) or Head over Heels will not load any .prg I have donwloaded . C16 Images on the whole run fine with no issues. On boot up the bytes free is correct at 60671. Could some memory or a IC Chip be causing this issue? Once again I thank you all in advance
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Posted By
KiCHY
on 2014-09-05
03:46:33
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Hi,
Since we're talking about PRG files, we can exclude the 1541/1551 turbo loader issues. What do you mean under ".prg will not load" and "refusing to load" descriptions exactly?
You enter DLOAD"THREEVE" and it says file not found, or loads it but after RUN it crashes?
Maybe the original prg filename causes the problem, is it possible that the SD2IEC can't handle some characters or converts them to another? You can anytime rename the problematic prg files to "a.prg" to test this theory
Mentioning that all C16 games run correctly and has problems with selected Plus/4 files may sign memory problems. I'm sure we have a HW diagnostics prg somewhere...
Bests,
KiCHY
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Posted By
Paradroid90
on 2014-09-05
06:30:54
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Hi Kichy
Thanks once again for your feedback.
Best description I can give when loading Threeve is that I have not changed the file name or altered the addresses via Yape. So a clean download
Through both Jiffy Dos and standard kernel, the demo starts to load, screen goes black but when it has finished the load, with Threeve for an example the screen goes white with a lilac border which I know it should do, but does not go no further and hangs/crashes.
It does this whether it is loaded on the SD2IEC or my 1541 Drive.
Sorry if I seemed vague before in my description, and thanks for your support in advance
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Posted By
MIK
on 2014-09-05
08:14:24
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Sorry if you know everything I'm going to say already, but just in case so it's covered from your point of view...
Adding to what KiCHY was saying with the file names. In short as I'm sure you know on C64 that files names should be no longer than 16 characters including the .prg extension on a real machine.
Also some modern day characters used on PC/Mac can cause problems with old 8bit machines such as the underscore symbol.
example: DEMO_OF_THE_YEAR_2014_SYS4112.PRG
The whole file name is way too long for 8bit machines including the extension so will cause problems and also the gaps that use _ in them will be a problem if they remain in the file name even if it's shorter such as A_B.PRG once copied over to the real machine.
Anything you see with an SYS address added to the file name of something you have downloaded is the start code for that program. Most files RUN is good to start a program if there is no SYS in the file name, however on C16/Plus4 some may have machine code data in memory where the start of BASIC is located so these have a jump code that start the program. DEMO_SYS4112.PRG once loaded would require you to type SYS4112 to start the program from Basic.
If you see anything with a G code in the file name such as GAME_G2000.PRG then from Basic your need to enter the machine code monitor and type: G2000
Obviously emulation ignores long file names and the underscore symbol _, or rather accepts them. Don't forget to remove the _ when being used on a real machine.
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Posted By
JamesC
on 2014-09-05
08:44:54
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Test your RAM with this program. If it finds a bad memory location, it will "crash" just like the programs you are trying to load.
10 TI$ = "000000"
20 FOR X = 16384 TO 64767
21 POKE X,0 : POKE X,128 : POKE X,255
22 PRINT X, TI$
23 NEXT X
Also: where did you get your JiffyDOS? There's a buggy beta out on the 'net. The more reliable one (still not perfect, but less buggy) costs money. Can you completely remove JiffyDOS and put the factory Kernal back in, so we can be sure you're not encountering a JiffyDOS bug?
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Posted By
Paradroid90
on 2014-09-05
09:21:46
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Once again guys thanks for your feedback and help.
I will try the program listed by James this afternoon and give you some feedback.
Thanks for the tips on the filenames MIK, and I am making sure the filenames are within the 16 character limit
I will keep you all posted
Once again thanks for your support
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Posted By
Paradroid90
on 2014-09-05
14:53:58
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Thanks for the great little program, and it has worked a treat
Run it under JIffydos and the original kernal and it stops at the same point and drops the Plus4 into the monitor
Screen displays
63952 004304
BREAK
PC SR AC XR YR
; 2D6D 31 10 00 F6
I assume that there is a problem with this memory location?
Any thoughts guys
Thanks once again for your support
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Posted By
siz
on 2014-09-05
15:28:48
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
I think it's not a problem with the memory. BASIC stores the variables downwards from the end of available memory ($fd00 in case of a 64k machine) and your cycle reached and overwritten one of the variables (most probably TI$) and generates some garbage which breaks the BASIC program execution. 
Edit: to answer your original question: try to switch off JiffyDOS (if it's switchable or swap back the original KERNAL if not) and try out software with that. I found some compatibility issues with JiffyDOS in case of a few programs.
Edit2: I've checked Threeve in YaPE with JiffyDOS ROM image for both the plus/4 and 1541 from a D64 image and it loads and works fine with JiffyDOS. Try stock KERNAL.
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Posted By
Paradroid90
on 2014-09-05
16:32:34
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Hi Siz, thanks for your support.
I tried to load Threeve with and without the JIffy DOS kernal switched on and still get the same result. I will try and dig out the original kernal chip and see that helps.
Thanks for all your help
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Posted By
JamesC
on 2014-09-05
19:35:14
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
@Siz - only TI$ is held at the top of memory in my ram-test. Numeric variables are held immediately after the end of BASIC program code.
TI$ is re-calculated from the jiffy clock on each request, it's not updated from the string pointer in RAM. Proof: run the ram-test for a few seconds, then pop into MONITOR, set 07F8 to 80 (so we can see RAM under ROM), and look at FCF8-FCFF. Change them all to FF, exit the monitor, and then PRINT TI$.
@Paradroid - yes, you have a bad memory location. Probably several. Here's how to tell:
a. Power down your Plus/4, leave it a minute or so (or put the original Kernal in!), then turn it on.
b. Type MONITOR and press Return.
c. Type M 07F8 07F8 and press Return.
d. Cursor up to the first 00 after 07F8 and change it to 80. Press Return.
e. Type M F9D0 and press Return.
f. Look for non-00 and non-FF values. Keep typing M and pressing Return until you reach FD00 -- at this point you're in the ACIA, not RAM, so we can ignore anything above FCFF.
We know F9D1 is bad, as it crashed the ram-test (the last number displayed was the last good byte). Odds are you'll see either 8-16 bad bytes in a row, or a quickly noticable pattern.
If you see no non-00, non-FF values, then power down, put JiffyDOS back in, and repeat this procedure. There's a chance that JiffyDOS itself is corrupting these values. (As I said before, JiffyDOS is buggy....)
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Posted By
Paradroid90
on 2014-09-06
03:16:47
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Thanks James your a Star
I will try that next and let you know how I get on later today
Thank you all for your help and kind welcome
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Posted By
SVS
on 2014-09-06
05:48:48
 | Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
If I can add some words,
BREAK
PC SR AC XR YR
; 2D6D 31 10 00 F6
The Break status means that system running has met a $00 instead of a valid 8501 code. Look at $2D6B: the value is surely a $00. The problem is why system has jumped to that location, that is not inside O.S., during its operations: this could even means a problem in the ROM.
Check the SP too (it should be shown after the "PC SR AC XR YR" of the break message. If it is too low (say under $B0) problem is the ROM.
Another check to do is, after the break, to test color keys (CTRL+1, CTRL+2, etc.). If the colors are not the standard ones, then it is confirmed the stack was overflow (and it should not).
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Posted By
Paradroid90
on 2014-09-17
02:03:46
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Hi everyone
Just to give you a quick update, just to say my plussy is now with my tech guru, and he is reviewing the memory and possible JIffy DOS issues for me
Once again thank you for all your help............Much Appreciated
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Posted By
MIK
on 2014-09-17
11:52:05
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Cool, hope everything turns out a-ok. All the best!
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Posted By
Paradroid90
on 2014-12-18
11:39:06
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Hi Guys sorry for reviving this old thread, but I recently got my Plussy back from my tech guru and tested the ram and found no faults.
I got the old girl out and tried James C idea
I got the following non 00 FF values
F9F8 - 44 8 Column
FA79 - 47 7 Column
FAFA - 46 6 Column
FAFB - 46 5 Column
FB7C - 6E 4 Column
FBFD - 04 4 Column
FC7F - 42 1 Column
FCF8 - 36 2 Column
30 3 Column
36 4 Column
37 5 Column
31 6 Column
05 7 Column
I presume FCF8 is correct as in basic registered 60671 which is total basic bytes free
Sorry I no good with HEX I am afraid, so is this normal ??
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Posted By
JamesC
on 2014-12-18
15:00:12
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Yes, the values starting at FCF8 are correct, if you just powered up the machine and went into MONITOR.
The other locations should be 00 or FF if you have the factory Kernal in. If JiffyDOS is switched in, JD could be storing things in those locations. (It shouldn't, but it's buggy.)
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Posted By
Paradroid90
on 2014-12-19
11:19:52
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Thanks for the Update James.
Jiffy DOS kernal still installed but the instructions were run in non Jiffy DOS mode.
I take it this indicates there is a problem with my JIffy DOS
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Posted By
JamesC
on 2014-12-19
15:10:56
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
It seems so. The easiest way to verify would be to remove JiffyDOS from the motherboard socket, putting the factory Kernal back in.
When you switch JiffyDOS off using its switch, you're not flipping back to the factory Kernal -- you're only turning off the JiffyDOS enhancements. Since the Kernal (on the JD rom) was patched to accomodate JiffyDOS, any patches that aren't turned off may still be buggy. Hence dropping the original (factory) Kernal back in for diagnosis purposes.
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Posted By
Paradroid90
on 2014-12-20
12:33:48
| Re: New to Plus4 scene - Introduction and SD2IEC and 1541 loading issues
Shame I do not have the original kernal chip now If anyone has a spare which I can use to test it would be appreciated
Once again thanks for your help James
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